parenteral preparation

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ยาเตรียมที่ใหโดยการฉีด Parenteral Preparation บทนํา (Introduction) ยาเตรียมที่ใหโดยการฉีด คือ การใหยาที่ไมผานทางเดินอาหาร โดยทั่วไปจะหมายถึงการฉีดยาทีตําแหนงตาง ของรางกาย (parenteral route) ดังตอไปนี1. การฉีดเขาหลอดเลือดดํา (intravenous route) 2. การฉีดเขาหลอดเลือดแดง (intraarterial route) 3. การฉีดเขากลามเนื้อ (intramuscular route) 4. การฉีดเขาใตผิวหนัง (subcutaneous or hypodermic route) 5. การฉีดเขาในระหวางชั้นของผิวหนัง (intracutaneous or intradermal route) 6. การฉีดเขาชองทอง (intraperitoneal route) 7. การฉีดเขาในไขสันหลัง (intrathecal route) 8. การฉีดเขาชองปอด (intrapleural route) 9. การฉีดเขาขอตอกระดูก (intraarticular route) 10. การฉีดเขาหัวใจ (intracardiac route) ฯลฯ ยาที่ใหโดยวิธีฉีดตาง นีจะอยูในรูปของยาน้ํา ซึ่งอาจจะเปนแบบยาน้ําใสไมมีตะกอน หรือยาแขวน ตะกอนก็ไดแลวแตวิธีฉีด ที่สําคัญคือไมวาจะเปนยาเตรียมแบบใดและใหโดยวิธีใด ยาเตรียมนั้นจะตองทําให ปราศจากเชื้อ ยาจึงมักจะมีราคาแพงกวายาที่ใหโดยการรับประทาน การดูดซึมยาจากการฉีดจะรวดเร็วแนนอน และสมบูรณกวาการรับประทาน ยาจะออกฤทธิ์เร็วกวาดวย ขอเสียที่สําคัญคืออันตรายจากการฉีดยาจะเกิดได งายกวา รุนแรงกวา และแกไขไดยากกวาการรับประทาน การฉีดเขาหลอดเลือดดํา จะไดรับยาในเลือดสูงอยางรวดเร็ว ยาจะไปที่หัวใจและถูกสงไปตามสวน ตาง ของรางกายอยางเร็ว จึงเปนวิธีที่ใชในกรณีที่ตองการผลของยาเร็วหรือทันที แตถาเกิดอันตรายจากยาก็ จะเกิดอยางเร็ว จนในบางครั้งอาจจะแกไขไมทัน การฉีดยาเขาหลอดเลือดดําจึงตองฉีดชา ผูสั่งใชยาตองมี ความรูดีเรื่องยา สามารถกําหนดขนาดยาที่จะใหไดอยางถูกตอง และรูวิธีแกไขหากเกิดอันตรายจากยาขึ้นมา (โดยทั่วไปแลว ขนาดยาที่ฉีดเขาหลอดเลือดดําจะนอยกวาขนาดยาที่ใหโดยวิธีอื่น เนื่องจากยาจะไปสู เปาหมายโดยตรงโดยไมผานการดูดซึมและการเปลี่ยนแปลงยา ตรงกันขามกับขนาดยาที่ใหแบบรับประทาน ซึ่งจะตองใหในขนาดที่มากกวาวิธีอื่น เพราะตองผานขั้นตอนการดูดซึมยา การเปลี่ยนแปลงและมีโอกาส เกิดปฏิกิริยากับสารอื่น ไดมากกวาวิธีฉีด) ยาที่จะฉีดเขาหลอดเลือดดําจะตองเปนยาน้ําใสไมมีตะกอน ปริมาตรของยานั้นใหไดตั้งแตขนาดนอย จนถึงปริมาตรมาก ได ซึ่งจะมากกวาวิธีฉีดอื่น การฉีดเขากลามเนื้อ จะใหผลชากวาฉีดเขาหลอดเลือดดํา แตเร็วกวาการรับประทาน จะเร็วกวา การฉีดเขาใตผิวหนัง เนื่องจากกลามเนื้อมีเลือดมาเลี้ยงมากกวา แตก็เร็วกวาไมมากนัก ยาบางชนิดจึงมี รายงานวาการฉีดเขากลามเนื้อและฉีดเขาใตผิวหนังใหผลในเวลาใกลเคียงกัน การฉีดเขากลามเนื้อเหมาะ

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ยาเตรียมที่ให้โดยการฉีด

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Page 1: Parenteral Preparation

ยาเตรียมที่ใหโดยการฉีด

Parenteral Preparation •บทนํา (Introduction)

ยาเตรียมที่ใหโดยการฉีด คือ การใหยาที่ไมผานทางเดินอาหาร โดยทั่วไปจะหมายถึงการฉีดยาที่ตําแหนงตาง ๆ ของรางกาย (parenteral route) ดังตอไปนี้

1. การฉีดเขาหลอดเลือดดํา (intravenous route) 2. การฉีดเขาหลอดเลือดแดง (intraarterial route) 3. การฉีดเขากลามเนื้อ (intramuscular route) 4. การฉีดเขาใตผิวหนัง (subcutaneous or hypodermic route) 5. การฉีดเขาในระหวางชั้นของผิวหนัง (intracutaneous or intradermal route) 6. การฉีดเขาชองทอง (intraperitoneal route) 7. การฉีดเขาในไขสันหลัง (intrathecal route) 8. การฉีดเขาชองปอด (intrapleural route) 9. การฉีดเขาขอตอกระดูก (intraarticular route) 10. การฉีดเขาหัวใจ (intracardiac route)

ฯลฯ ยาที่ใหโดยวิธีฉีดตาง ๆ นี้ จะอยูในรูปของยาน้ํา ซึ่งอาจจะเปนแบบยาน้ําใสไมมีตะกอน หรือยาแขวนตะกอนก็ไดแลวแตวิธีฉีด ที่สําคัญคือไมวาจะเปนยาเตรียมแบบใดและใหโดยวิธีใด ยาเตรียมนั้นจะตองทําใหปราศจากเชื้อ ยาจึงมักจะมีราคาแพงกวายาที่ใหโดยการรับประทาน การดูดซึมยาจากการฉีดจะรวดเร็วแนนอน และสมบูรณกวาการรับประทาน ยาจะออกฤทธิ์เร็วกวาดวย ขอเสียที่สําคัญคืออันตรายจากการฉีดยาจะเกิดไดงายกวา รุนแรงกวา และแกไขไดยากกวาการรับประทาน การฉีดเขาหลอดเลือดดํา จะไดรับยาในเลือดสูงอยางรวดเร็ว ยาจะไปที่หัวใจและถูกสงไปตามสวนตาง ๆ ของรางกายอยางเร็ว จึงเปนวิธีที่ใชในกรณีที่ตองการผลของยาเร็วหรือทันที แตถาเกิดอันตรายจากยาก็จะเกิดอยางเร็ว จนในบางครั้งอาจจะแกไขไมทนั การฉีดยาเขาหลอดเลือดดําจึงตองฉีดชา ๆ ผูส่ังใชยาตองมีความรูดีเรื่องยา สามารถกําหนดขนาดยาที่จะใหไดอยางถูกตอง และรูวิธีแกไขหากเกิดอันตรายจากยาขึ้นมา (โดยทั่วไปแลว ขนาดยาที่ฉีดเขาหลอดเลือดดําจะนอยกวาขนาดยาที่ใหโดยวิธีอื่น ๆ เนื่องจากยาจะไปสูเปาหมายโดยตรงโดยไมผานการดูดซึมและการเปลี่ยนแปลงยา ตรงกันขามกับขนาดยาที่ใหแบบรับประทาน ซึ่งจะตองใหในขนาดที่มากกวาวิธีอื่น ๆ เพราะตองผานขั้นตอนการดูดซึมยา การเปลี่ยนแปลงและมีโอกาสเกิดปฏิกิริยากับสารอื่น ๆ ไดมากกวาวิธีฉีด) ยาที่จะฉีดเขาหลอดเลือดดําจะตองเปนยาน้ําใสไมมีตะกอน ปริมาตรของยานั้นใหไดตั้งแตขนาดนอย ๆ จนถึงปริมาตรมาก ๆ ได ซึ่งจะมากกวาวิธีฉีดอื่น ๆ การฉีดเขากลามเนื้อ จะใหผลชากวาฉีดเขาหลอดเลือดดํา แตเร็วกวาการรับประทาน จะเร็วกวาการฉีดเขาใตผิวหนัง เนื่องจากกลามเนื้อมีเลือดมาเลี้ยงมากกวา แตก็เร็วกวาไมมากนัก ยาบางชนิดจึงมีรายงานวาการฉีดเขากลามเนื้อและฉีดเขาใตผิวหนังใหผลในเวลาใกลเคียงกัน การฉีดเขากลามเนื้อเหมาะ

Page 2: Parenteral Preparation

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สําหรับกรณีที่ตองการผลเร็ว แตไมจําเปนตองทันที และในกรณีที่ตองการใหยาออกฤทธิ์อยูไดนานโดยการเตรียมยาใหสามารถจับ (deposit) อยูกับเนื้อเยื่อบริเวณที่ฉีดแลวรางกายคอย ๆ ดูดซึมยาเอาไปใช ยาเตรียมจะอยูในรูปแบบยาน้ําไมมีตะกอนหรือยาแขวนตะกอนได การฉีดเขาใตช้ันผิวหนงั ยาเตรียมจะเปนแบบยาน้ําใสไมมีตะกอน หรือยาแขวนตะกอนก็ไดเชนกัน แตควรเปนสารที่ไมระคายเคือง ปริมาตรที่ฉีดนอยกวาการฉีดเขากลามเนื้อ การดูดซึมยาจะชา บอยคร้ังที่พบวาไมเร็วไปกวาแบบรับประทาน แตเปนวิธีที่จะใหเมื่อตองการใหยาออกฤทธิ์ทีละนอยแตนาน หรือในรายที่ไมสามารถใหยาแบบรับประทานได หรือกรณีที่ไมตองการใหรางกายตอบสนองตอยาเร็วเกินไป การรับประทานยา การฉีดเขาหลอดเลือดดํา การฉีดเขากลามเนื้อ และการฉีดเขาใตผิวหนังเปน 4 วิธี ที่ใชบอยกวาวิธีอื่น ๆ ซึ่งมักจะใชในกรณีพิเศษเทานั้น เชน การฉีดเขาในระหวางชั้นผิวหนังจะใชเมื่อตองการทดสอบการแพยาหรือภูมิคุมกันโรค การฉีดเขาไขสันหลังสําหรับยาบางชนิดที่ไมสามารถผาน blood brain barrier ได หรือการฉีดเขาชองทองที่มักจะใชกับสัตวทดลองเพื่องานวิจัย เพราะเปนวิธีที่เกิดติดเชื้อไดงาย เปนตน ขนาดของยาและปริมาตรยาชนิดเดียวกันที่ใหตาม 4 วิธีดังกลาวนี้จะไมเทากัน ดวยเหตุผลตามที่เคยกลาวไวบางแลว ขอควรทราบอีกขอหนึ่งคือ สําหรับยาบางชนิดถาใหโดยวิธี ตาง ๆ กัน จะใหผลในการรักษาตางกันไปดวย เชนยา magnesium sulphate พบวาถาใหโดยการรับประทานยาจะไมถูกดูดซึมผานทางเดินอาหาร และใหผลเปนยาระบาย แตถาฉีดเขาหลอดเลือดดํายาจะไปออกฤทธิ์กดระบบประสาทกลางและคลายกลามเนื้อลายได •คุณสมบัติของยาฉีด การเตรียมยาฉีดนั้น ตองทําใหปราศจากเชื้อ สารที่จะนํามาใชจะตองมีความสะอาดและบริสุทธิ์สูง และตองใชขบวนการผลิตที่พิเศษ จึงจะผลิตยาที่มีคุณภาพและความปลอดภัยตอผูปวย ซึ่งคุณสมบัติที่ดีของยาฉีดควรเปนลักษณะดังนี้ 1. มีความปลอดภัย (Safety) ยาฉีดที่ดีตองมีความปลอดภัย และไมเปนอันตรายตอผูปวย โดยสารที่นํามาผลิตและภาชนะบรรจุจะตองไดรับการตรวจสอบวาไมทําปฏิกิริยา หรือปลอยสารที่ไมตองการออกมา และตองไดรับการตรวจสอบ โดยการใชในสัตวทดลองกอน 2. ปราศจากเชื้อ (Sterility) ยาฉีดตองไมมีเชื้อจุลินทรียปะปนตั้งแตเริ่มขบวนการผลิต จนถึงนํายาไปใช 3. ปราศจากไพโรเจน (Free from pyrogen) ไพโรเจนเปนผลิตภัณฑที่ไดจากขบวนการมีชีวิตของจุลินทรีย เมื่อเกิดขึ้นในยาเตรียมและนําไปฉีดเขารางกายจะทําใหมีอาการหนาวสั่น หรืออุณหภูมิของรางกายสูงขึ้นเหมือนเปนไข 4. ใส (Clarity) ยาฉีดตองปราศจากเศษผงใด มิฉะนั้นอาจจะไปอุดตันเสนเลือดฝอย ซึ่งจะเปนอันตรายตอรางกาย ยกเวนยาฉีดพวก suspension และ emulsion ซึ่งจะใหไดเฉพาะทางกลามเนื้อลายเทานั้น

Page 3: Parenteral Preparation

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5. มีความคงตัว (Stability) ยาฉีดตองมีความคงตัว ดีทั้งทางกายภาพและทางเคมี รวมทั้งภาชนะที่บรรจุ ตองมีความคงตัวตั้งแตเริ่มผลิต เก็บรักษาและเมื่อนําไปใช •ชนิดของยาฉีด 1. ยาฉีดในรูปสารละลายพรอมที่ใชฉีดไดเลย ชื่อยาจะขึ้นตนดวยชื่อยา ลงทายดวยคําวา injection เชน insulin injection 2. ยาเปนผงแหงหรือของเหลวขน เมื่อนํามาใชตองเติมตัวทําละลายที่เหมาะสมลงไป จะไดสารละลายใหมีคุณสมบัติเปนยาฉีดได ชื่อยาจะขึ้นตนดวยคําวา Sterile แลวตามดวยชื่อยา เชน Sterile procaine Hydrochloride ถายานั้นมีสวนผสมของยาอื่น นอกเหนือจากตัวยาสําคัญ จะมีชื่อขึ้นตนดวยชื่อยาตามดวยคําวา For injection เชน Erythromycin For injection 3. ยาฉีดที่อยูในรูปยาแขวนตะกอน ซึ่งมียาแขวนลอยอยูในของเหลวที่เหมาะสม หามฉีดเขาเสนเลือดและไขสันหลัง มีชื่อขึ้นตนดวยคําวา Sterile ตามดวยชื่อยา และลงทายดวยคําวา Suspension เชน Sterile Hydrocortisone Acetate suspension 4. ยาเปนผงแข็ง เมื่อใชใหเติมตัวทําละลายที่เหมาะสม จะไดยาแขวนตะกอนที่มีคุณสมบัติเปนยาฉีดได มีชื่อขึ้นตนดวย Sterile ตามดวยชื่อยา ลงทายดวย For suspension เชน Sterile chloramphenicol for suspension 5. ยาที่อยูในรูป Emulsion มีคุณสมบัติเปนยาฉีดได ใชฉีดไดเลย หามฉีดเขาเสนเลือด และไขสันหลัง มีชื่อขึ้นตนดวย Sterile ตามดวยชื่อยา ลงทายดวยคําวา emulsion เชน Sterile phytonadion Eulsion •สวนประกอบของยาฉีด

1. ตัวยาสําคัญ 2. ตัวทําละลาย ไดแก

Water for injection Sterile water for injection\Bacteriostatic water for injection Oil for injection เชน น้ํามันพืช (น้ํามันงา, น้ํามันเมล็ดฝาย เปนตน)

3. สารอื่น ๆ ที่เติมลงไปเพื่อจุดประสงคเฉพาะ เชน 3.1 เพื่อชวยละลายตัวยา 3.2 เพื่อชวยใหยามีความคงตัวทั้งกายภาพและเคมี 3.3 เพื่อคงสภาพปราศจากเชื้อโดยเฉพาะยากลุม Multiple dose 3.4 เพื่อลดความเจ็บปวดหรือระคายเคืองขณะฉีด เชน เติม Xylocain 1% Hydrocortisone,

Heparin เล็กนอย ใน Amphotericin B 3.5 เพื่อใหยาแขวนตะกอนกระจายอยูได เชน

Sodium carboxymethylcellulose Polyvinylpyrrolidone Methylcellulose

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•ภาชนะบรรจุ แบงเปน

1. Vial ใชบรรจุยาทีเปนผงแข็ง กอนใชตองเติมตัวทําละลายที่เหมาะสม 2. Ampule บรรจุยาที่เปนของเหลวใชฉีดไดเลย หรืออาจจะแบงเปน

1. Single-Dose container เปนยาที่เมื่อเปดใชแลว จะตองใชใหหมดภายในครั้งเดียว หรือถาใชไมหมดก็ใหทิ้งสวนที่เหลือไป มีปริมาตรไมเกิน 1000 ml. ยาที่ฉีดเขาไขสันหลังตองบรรจุใน Single-dose container เทานั้น 2. Multiple-dose container เปนยาที่แบงใชไดหลายครั้ง มักเติมสารกันเชื้อจุลินทรีย •การเขียนฉลากยาฉีด

1. ชื่อตํารับยา 2. ความเขมขนหรือรอยละของตัวยาสําคัญ 3. ปริมาณของตัวยาสําคัญ สําหรับยาที่อยูในรูปผงแหง 4. ปริมาตรของของเหลวที่ใชเติมลงในยาที่อยูในรูปผงแหง 5. ทางยาฉีด 6. การเก็บรักษา ที่อุณหภูมิใด กันแสงหรือไม 7. วันหมดอายุของยานั้น 8. ผูผลิต ผูแทนจําหนาย เลขทะเบียนการผลิต

•การเตรียมยาฉีด

1. ชั่งสาร 2. ละลายในน้ํากระสายยาและปรับปริมาตร 3. กรองผาน membrane filter 4. บรรจุในภาชนะและปดผนึก 5. Autoclave ที่ 121 องศาเซลเซียสเปนเวลา 15 นาที 6. ตรวจสอบคุณภาพและปดฉลาก

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•ตัวอยางยาฉีดที่ใชในทางสัตวแพทย

Ivermectin

Overview Parasitic diseases are common in animals. Parasites can affect the skin, ears, stomach and intestines, and the internal organs including the heart, lungs and liver. Several drugs have been developed to kill or prevent parasites such as fleas, ticks, mites and worms. Ivermectin and related drugs are among the most effective of these. Ivermectin is a parasite control drug. Ivermectin causes neurologic damage to the parasite, resulting in paralysis and death. Ivermectin has been used to prevent parasite infections, as with heartworm prevention, and to treat infections, as with ear mites. Ivermectin is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Brand Names and Other Names This drug is registered for use in animals only. Human formulations: None Veterinary formulations: Ivomec® (Merial), Zimectrin® (Farnam), Eqvalan® (Merial), Heartgard® (Merial), Iverhart® (Virbac) and various generic preparations Uses of Ivermectin Ivermectin is used to control skin parasites, gastrointestinal parasites and parasites within the bloodstream. Ivermectin prevents development of heartworm disease in dogs and cats. Ivermectin can be used in an extra-label manner to kill microfilaria (microscopic offspring) in heartworm infected dogs. Ivermectin is not effective against tapeworms and liver flukes. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, ivermectin can cause side effects in some animals. Ivermectin should not be used in animals with known hypersensitivity or allergy to the drug. Ivermectin should be used with caution in collie breeds or collie mixed breeds due to potential toxic effects. This is particularly true when using higher doses. Ivermectin should not be used in dogs that are positive for heartworm disease except under strict supervision of a veterinarian. Prior to starting a heartworm prevention containing ivermectin, the dog should be tested for heartworms. Ivermectin generally should be avoided in dogs less than 6 weeks of age. Ivermectin is relatively safe, but overdoses can occur if massive amounts are given or if the drug is given to heartworm positive dogs. Signs of overdose, including stumbling, tremors, blindness, disorientation or weakness, generally occur within 12 hours of overdose. In heartworm positive dogs, supportive treatment for shock may be required.

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How Ivermectin Is Supplied Ivermectin is available in 10 mg/ml and 2.7 mg/ml injectable form; 0.153 percent and 1.87 percent paste form; 10 mg/ml liquid oral form and 68 mcg, 136 mcg and 272 mcg tablets. Heartgard Plus® and Iverhart® are available in various concentrations of ivermectin combined with pyrantel pamoate. Dosing Information Medication should never be administered without first consulting your veterinarian. The dose for ivermectin varies from species to species and also depends on the intent of treatment. General dosing guidelines follow. For dogs: Dose is 0.0015 to 0.003 mg per pound (0.003 to 0.006 mg/kg) once a month for heartworm prevention; 0.15 mg per pound (0.3 mg/kg) once, then repeat in 14 days for skin parasites; and 0.1 mg per pound (0.2 mg/kg) once for gastrointestinal parasites. For cats: Dose is 0.012 mg per pound (0.024 mg/kg) once monthly for heartworm prevention. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

Chlorpromazine Overview Chlorpromazine belongs to a class of drugs known as phenothiazine derivatives. Other related drugs in this class include acepromazine and prochlorperazine. The exact mechanism of action of the phenothiazine derivatives is not completely understood. The drugs work by somehow blocking dopamine receptors in the nervous system and may even inhibit the release of dopamine. These drugs are thought to affect the part of the brain responsible for controlling body temperature, metabolic rate, vomiting, blood pressure and alertness. Compared to other phenothiazines, chlorpromazine has moderate sedative effects and moderate to strong anti-vomiting effects. Chlorpromazine is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug. Brand Names and Other Names This drug is registered for use in humans only. Human formulations: Thorazine® (SKF), Ormazine® (Hauck) and various generics. Veterinary formulations: None

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Uses of Chlorpromazine Chlorpromazine is used to reduce nausea and vomiting. Infrequently, chlorpromazine may be used as a sedative. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, chlorpromazine can cause side effects in some animals. Chlorpromazine should not be used in animals with known hypersensitivity or allergy to the drug. Chlorpromazine should be avoided in animals with glaucoma, low blood pressure or shock. This drug should be used with caution in animals with liver disease, heart disease or older patients. Chlorpromazine may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with chlorpromazine. Such drugs include certain narcotics, barbiturates, propranolol, epinephrine and some anti-diarrheal medications. Constipation, sedation and low blood pressure may occur after administration of chlorpromazine. In cases of overdose, chlorpromazine can cause tremors and drooling. How Chlorpromazine is Supplied Chlorpromazine is available in 10 mg, 25 mg, 50 mg, 100 mg and 200 mg tablets. Chlorpromazine is also available in 30 mg, 75 mg, 150 mg, 200 mg and 300 mg extended release capsules. An oral solution is available in 2 mg/ml syrup and 30 mg/ml concentrate, both in 120 ml bottles. Rectal suppositories of 25 mg and 100 mg are available. Injectable chlorpromazine is also available in 25 mg/ml concentration in 1 ml and 2 ml ampules as well as a 10 ml bottle. Dosing Information Medication should never be administered without first consulting your veterinarian. To treat nausea and vomiting in dogs, chlorpromazine is dosed at 0.12 to 0.25 mg per pound (0.25 to 0.5 mg/kg) subcutaneously or intramuscular every 6 to 24 hours. It can also be given intravenous at a dose of 0.02 to 0.05 mg per pound (0.05 to 0.1 mg/kg) every 6 to 8 hours as needed. To treat nausea and vomiting in cats, chlorpromazine is dosed at 0.005 to 0.012 mg per pound (0.01 to 0.025 mg/kg) intravenous every 6 to 8 hours as needed. If vomiting is not severe, chlorpromazine can be administered orally at a dose of 0.05 to 1 mg per pound (0.1 to 2.2 mg/kg) 1 to 4 times daily. For sedation, chlorpromazine is dosed at 1.5 mg per pound (3 mg/kg) by mouth once or twice daily. The injectable sedative dose is 0.25 mg per pound (0.5 mg/kg) intramuscular or intravenous once or twice daily. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

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Terbutaline Sulfate Overview Terbutaline is a drug that stimulates type 2 beta-adrenergic receptors. Beta-receptors are cell membrane targets that modify organ activity when stimulated by norepinephrine, epinephrine or related drugs. Stimulation of beta-2 receptors in smooth muscle causes the muscle to relax. This muscle relaxation results in dilation of the airways and blood vessels and can slow down or halt premature uterine contractions and labor. Terbutaline predominately stimulates beta-2 receptors in the airways and uterus, causing these muscles to relax. The major use of terbutaline in pets is in the treatment of bronchial disease such as asthma and bronchitis. Terbutaline is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug. Brand Names and Other Names This drug is registered for use in humans only. Human formulations: Brethine® (Novartis), Bricanyl® (Hoechst Marion Roussel) and various generic preparations Veterinary formulations: None Uses of Terbutaline The primary use of terbutaline in animals is to assist breathing in specific airway diseases through its bronchodilation effects. Terbutaline has been used as an adjunct treatment for bronchitis, collapsing trachea, asthma and mild heart failure. Little information is available on the effects of halting premature labor in animals and this is not a routine use of terbutaline in animals. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, terbutaline can cause side effects in some animals. Terbutaline should not be used in animals with known hypersensitivity or allergy to the drug. Terbutaline should be used cautiously in animals with diabetes, high blood pressure, overactive thyroid gland (hyperthyroidism), animals taking thyroid supplement (L-thyroxine) or those with a seizure disorder or epilepsy. Terbutaline should be avoided if any heart rhythm abnormalities are present. Terbuatine may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with terbutaline. Such drugs include certain antidepressants and anesthetics. Adverse effects are generally related to the dose of terbutaline and can include tremors, increased heart rate or nervousness.

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How Terbutaline Is Supplied Terbutaline is available in 2.5 mg and 5 mg tablets. It is also available in 1 mg/ml injectable form as well as an inhaler form. Dosing Information Medication should never be administered without first consulting your veterinarian. For dogs and cats, the injectable form of terbutaline is dosed at 0.005 mg per pound (0.01 mg/kg) every 4 to 6 hours. For dogs, the tablet form of terbutaline is dosed at 1.25 to 5 mg per dog three times per day. For cats, the tablet form of terbutaline is dosed at 0.05 to 0.1 mg per pound (0.1 to 0.2 mg/kg) twice daily. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

Doxapram Overview Doxapram is a drug that stimulates the central nervous system. An important aspect of the drug is its effect on the brain's respiratory system. Doxapram affects breathing by directly stimulating the brain's breathing center. Even though in certain situations doxapram can temporarily increase breathing rates and increase the amount of air inhaled, this does not result in increased oxygen in the blood. Doxapram also increases the work necessary to breathe, thus consuming any additional oxygen and producing additional carbon dioxide. The effects of doxapram, if any are to occur, are usually seen within 2 minutes of administration. Doxapram should not be used as a substitute for cardiopulmonary resuscitation and artificial respiration. If used in CPR, it should only be used as an adjunct to standard treatment. Doxapram is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Brand Names or Other Names This drug is registered for use in animals only. Human formulations: Dopram (Robins) Veterinary formulations: Dopram-V (Fort Dodge)

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Use of Doxapram Doxapram is used to stimulate breathing during and after anesthesia or to speed awakening after anesthesia. For newborns, doxapram is used to initiate or stimulate breathing following difficult births and cesarean sections. Precaution and Side Effects While generally safe and effective when prescribed by a veterinarian, doxapram can cause side effects in some animals. Doxapram should not be used in animals with known hypersensitivity or allergy to the drug. Doxapram should not be used in animals with a history of seizures, head trauma or heart failure. This drug should also be avoided in animals with severely high blood pressure, asthma, heart rhythm irregularities, airway obstructions or hyperthyroidism. Doxapram may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with doxapram. Such drugs include muscle relaxants and some anesthetics. Side effects associated with doxapram include high blood pressure, heart rhythm irregularities, seizures or hyperventilation. How Doxapram is Supplied Doxapram is available in 20 mg/ml injectable concentration in 20 ml vials. Dosing Information Medication should never be administered without first consulting your veterinarian. To stimulate breathing following anesthesia, doxapram is dosed at 0.5 to 2.5 mg per pound (1 to 5 mg/kg) intravenous. To stimulate breathing in newborns, doxapram is dosed at 1 to 2 drops under the tongue per baby or 0.1 ml intravenous in the umbilical vein. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects.

Ampicillin Overview Ampicillin is an antibiotic related to penicillin used to treat and prevent bacterial infections. As with similar penicillin drugs, ampicillin kills bacteria by inhibiting production of the bacteria cell wall. Other related drugs include penicillin G, amoxicillin and ticarcillin. Many bacteria develop resistance to ampicillin. Ampicillin is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

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Brand Names and Other Names This drug is registered for use in humans and animals. Human formulations: Totacillin-N® (SK-Beecham), Polycillin-N®, Omni-pen® Veterinary formulations: Polyflex® (Fort Dodge), Amp-Equine® (Pfizer) Ampicillin is supplied by numerous drug companies with a variety of trade names and various generic formulations. Uses of Ampicillin Ampicillin is prescribed to treat or control infections caused by susceptible bacteria. Infections treated with ampicillin often include wounds, skin infections, tooth abscesses and bladder infections. Ampicillin is not effective against infections caused by viruses or parasites (such as worms). Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, ampicillin can cause side effects in some animals. Ampicillin should not be used in animals with known hypersensitivity or allergy to the drug. Ampicillin may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with ampicillin. It is common for animals to develop diarrhea or loose stools following treatment with oral ampicillin because this antibiotic can change the bacterial population of the pet’s intestinal tract. If your pet has diarrhea, notify your veterinarian. Ask if the medication should be changed. How Ampicillin Is Supplied Ampicillin is available in 250 mg and 500 mg capsules and also comes in different liquid oral suspensions (liquids that should be gently shaken). Ampicillin is also available in various injectable concentrations. Dosing Information Medication should never be administered without first consulting your veterinarian. The typical dose of ampicillin ranges from 5 to 10 mg per pound (11 to 22 mg/kg) three or four times a day. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

Percorten-V® Overview Addison’s disease – more properly known as hypoadrenocorticism – is a deficiency of hormones (cortisol, aldosterone) normally produced by the adrenal glands. Consequences of

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this disorder can include extreme weakness, shock, vomiting, diarrhea, disturbances of blood potassium and sodium, abnormal heart rhythms and death. Hypoadrenocorticism in dogs is an autoimmune disease that leads to destruction of the adrenal gland cortex (outer layers) and a deficiency of vital hormones. One of the hormones produced by the adrenal glands and absent in Addison’s disease is aldosterone. This hormone assists the kidney in retaining needed sodium and getting rid of excess potassium. Deficiency of the hormone increases sodium loss in the urine, reduces blood pressure and increases blood potassium. High blood potassium can be dangerous, leading to fatal cardiac arrhythmias. Treatment of Addison’s disease requires replacement of missing hormones. It is essential to replace aldosterone with a similar hormone. Desoxycorticosterone is an injectable replacement (hormone) belonging to a class of drugs known as mineralocorticoids steroids. Desoxycorticosterone is also called DOCP. DOCP acts on the kidney to increase the absorption of sodium and facilitates excretion of potassium from the body. The effects of DOCP last between 21 and 30 days following injection. DOCP is not effective if kidney function is significantly impaired. DOCP is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Brand Names and Other Names This drug is registered for use in animals only. Human formulations: None Veterinary formulations: Percorten-V® (Novartis Animal Health) Uses of Desoxycorticosterone Desoxycorticosterone is used to treat Addison’s disease in dogs. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, desoxycorticosterone can cause side effects in some animals. Desoxycorticosterone (DOCP) should not be used in animals with known hypersensitivity or allergy to the drug. DOCP may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with desoxycorticosterone. Such drugs include furosemide, insulin, digoxin and amphotericin B. DOCP use should be avoided in animals with heart failure or kidney failure. Since DOCP is available only as an injection. Soreness and inflammation at the site of injection is a potential adverse effect. Overdose of DOCP leads to increased thirst and urination, fluid retention and possible weakness. How Desoxycorticosterone Is Supplied Desoxycorticosterone is available as a 25 mg/ml injection. Dosing Information Medication should never be administered without first consulting your veterinarian. Initially, desoxycorticosterone is dosed at 1 mg per pound (2.2 mg/kg) every 25 to 30 days. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

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Aminophylline Overview When the smooth muscle in the airways contracts, air flow into and within the lungs is impeded. This condition is often referred to as bronchospasm and occurs in disorders such as asthma. Aminophylline relaxes the smooth muscles in the airways and provides relief from obstructive airway diseases, such as asthma. It also acts as a central nervous stimulant. Aminophylline belongs to a class of drugs called bronchodilators. Related drugs include theophylline. Aminophylline is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. This drug is not approved for use in animals by the Food and Drug Administration (FDA) but may be prescribed legally by veterinarians as an extra-label drug. Brand Names and Other Names This drug is registered for use in humans only. Human formulations: Various generic preparations exist. Manufacturers include Abbott, Balan, Bioline, Roxane, Searle and URL. Veterinary formulations: None Use of Aminophylline Aminophylline is used to open the airway in the treatment of bronchitis and asthma. Aminophylline has been used to stimulate the central nervous system and to treat apnea in neonates. It has also been used as a cardiac stimulant in heart failure. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, aminophylline may cause side effects in some animals. Aminophylline should not be used in animals with known hypersensitivity or allergy to the drug. The drug should be used with caution in animals with liver or heart disease. Possible side effects include anxiety, nervousness and gastrointestinal problems. Aminophylline may interact with other medications. Consult your veterinarian to determine if other drugs your pet is receiving could interact with aminophylline. Such drugs include ketoconazole, rifampin, diuretics, calcium channel blockers, cimetidine, corticosteroids and ephedrine.

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How Aminophylline is Supplied Aminophylline is available in 100 mg and 200 mg immediate-release tablets, and as a 105 mg/5 ml oral liquid. Injectable aminophylline is available in a 250 mg/10 ml concentration. In addition, aminophylline is also available as 250 mg and 500 mg suppositories. Dosing Information Medication should never be administered without first consulting your veterinarian. In dogs, aminophylline is dosed at 3 to 5 mg per pound (6 to 11 mg/kg) orally, or by injection, every 8 hours. In cats, aminophylline is dosed at 2 mg per pound (5 mg/kg) orally every 8 to 12 hours. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless otherwise directed by your veterinarian.

Erythropoietin Overview Erythropoietin is a synthetic form of the naturally occurring hormone normally produced in the kidney. Erythropoietin stimulates the production of red blood cells (red corpuscles). Deficiency of erythropoietin leads to anemia, an insufficient number of red blood cells. This most often occurs with kidney disease. Erythropoietin is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug. Brand Names and Other Names This drug is registered for use in humans only. Human formulations: Epogen® (Amgen), Procrit® (Ortho Biotech) and various generics. Veterinary formulations: None

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Uses of Erythropoietin The primary use of erythropoietin is to treat anemia associated with chronic kidney failure. Iron is frequently supplemented while an animal is under treatment with erythropoietin. If the pet becomes more anemic during treatment, an immunity-related resistance should be considered and the drug discontinued. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, erythropoietin can cause side effects in some animals. Erythropoietin should not be used in animals with known hypersensitivity or allergy to the drug. Erythropoietin should not be used in animals with uncontrolled high blood pressure. Erythropoietin may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with erythropoietin. With continued use, erythropoietin may become ineffective. In some animals, the immune system may react against the drug, making the body resistant to the beneficial effect of the drug. How Erythropoietin Is Supplied Erythropoietin is supplied in injectable form only. It is available in 2,000 units, 3,000 units, 4,000 units, 10,000 units and 20,000 units/ml vials. Dosing Information Medication should never be administered without first consulting your veterinarian. The initial dose of erythropoietin typically is 50 units per pound (25 U/kg) three times per week. This is continued for several weeks. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

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Gentamicin Overview Gentamicin is an antibiotic that inhibits bacteria by suppressing protein synthesis and growth. Through this mechanism, gentamicin kills bacteria rapidly. Gentamicin belongs to a general class of drugs known as aminoglycosides. Other related drugs in this class include neomycin, amikacin, tobramycin and kanamycin). Gentamicin is effective against a wide range of bacteria. It is effective against bacteria that infect the bloodstream, respiratory tract, skin, sinuses, ear canal and bladder. Gentamicin is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Gentamicin is available for injection and topical use (such as skin or eye infections). Brand Names and Other Names This drug is registered for use in humans and animals. Human formulations: Garamycin® (Schering), Jenamicin® (Hauck) and various generics Veterinary formulations: Gentocin® (Schering) and various generics Uses of Gentamicin Gentamicin is used in both dogs and cats to treat or prevent bacterial infections including respiratory infections, wound infections, pneumonia, bloodstream infections, bladder infections and infections of the skin and ear. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, gentamicin can cause side effects in some animals. Gentamicin should not be used in animals with known hypersensitivity or allergy to the drug. The most serious adverse effect from gentamicin and others in this class of drugs is damage to the kidneys. This effect is related to duration of dose and the condition of the kidneys prior to treatment. (The longer the duration of treatment, the more likely this problem is to occur.) Therefore, the status of the health of the kidneys must be assessed before gentamicin is administered to animals. Animals should not receive gentamicin if they are dehydrated or have other diseases that may risk the health of their kidneys. Gentamicin and other aminoglycosides can cause loss of hearing (ototoxicity) in animals or loss of balance (vestibulotoxicity). High doses can cause muscle paralysis. Do not administer topically if there is evidence of skin sensitivity to the compound (redness, irritation, itching). Gentamicin may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with gentamicin. When gentamicin is applied topically, such as on the eyes or in the ears, it is poorly absorbed; adverse reactions, described above, may be minimized with this application.

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How Gentamicin Is Supplied Gentamicin is available in a 100 mg/ml injectable solution. Gentamicin is available in a wide variety of topical solutions for treatment of superficial eye infections or ear solutions for infections in the ear. Dosing Information Medication should never be administered without first consulting your veterinarian. The usual dose in dogs is 5 to 7 mg per pound (10 to 15 mg/kg) every 24 hours by intravenous, intramuscular or subcutaneous administration. The usual dose for cats 3 to 4 mg per pound (5 to 8 mg/kg) once daily by intravenous, intramuscular or subcutaneous administration. When applied topically, the dose and frequency depends on the type of condition being treated. Gentamicin is usually applied two or three times daily. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

Oxytocin Overview Oxytocin is a hormone naturally produced in the part of the brain called the hypothalamus. This hormone is especially important in reproduction. Oxytocin increases the ability of sodium molecules to pass into the muscles of the uterus. This effect causes the uterus to contract. In birth, this helps to move the fetus into the birth canal. Oxytocin administration can also lead to the release of milk from the breasts. Oxytocin is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Brand Names and Other Names This drug is registered for use in humans and animals. Human formulations: Pitocin® (Park-Davis), Syntocinon® (Sandoz) and various generic preparations Veterinary formulations: Various generic preparations Uses of Oxytocin The primary use of oxytocin is to induce labor in animals having weak or no contractions. The drug enhances uterine contractions at the time of fetal delivery. Oxytocin is also used medically to expel any residual placental material that might be left in the uterus. This may prevent the subsequent development of metritis. Oxytocin helps to stimulate milk release after delivery.

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Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, oxytocin can cause side effects in some animals. Oxytocin should not be used in animals with known hypersensitivity or allergy to the drug. Oxytocin may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with oxytocin. Oxytocin should not be used if the fetus is in an abnormal position or is too large to pass through the birth canal. Oxytocin should only be used if the cervix is dilated. Oxytocin should not be used if an animal has uncorrected low blood sugar or untreated low blood calcium. If inappropriately used, oxytocin can cause uterine rupture or pain from excessive uterine cramping. How Oxytocin Is Supplied Oxytocin is typically available in injectable form and comes in 20 units/ml bottles. It is also available in 10 units/ml ampules and multi-dose vials. Oxytocin is also available as a 40 units/ml nasal spray. This form of oxytocin is not for use to stimulate uterine contractions and should not be used for that purpose. Dosing Information Medication should never be administered without first consulting your veterinarian. There is a wide dose range for oxytocin, depending on the stage of labor. Typically, oxytocin is given to dogs and cats at a dose of 2 to 20 units intravenous or intramuscular. At least 30 minutes should elapse before giving another dose. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects.

Penicillin G Overview Penicillin G is an antibiotic used to treat and prevent bacterial infections. This is a natural penicillin and is cultured from the bacteria Penicillium chrysogenum. As with similar penicillin drugs, penicillin G kills bacteria by inhibiting production of the bacteria cell wall. Other related drugs include ampicillin, amoxicillin and ticarcillin. Many bacteria develop resistance to penicillin G. Penicillin G is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Brand Names and Other Names This drug is registered for use in humans and animals. Human formulations: Penicillin G Potassium® (Apothecon), Pfizerpen® (Roerig) and various

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generic preparations Veterinary formulations: Crystacillin® (Solvay), Flo-Cillin® (Fort Dodge), Crystiben® (Solvay), Dual-Pen® (TechAmerica) and various generic preparations Uses of Penicillin G Penicillin G is prescribed to treat or control infections caused by susceptible bacteria. Infections treated with penicillin G often include wounds, skin infections, tooth abscesses and bladder infections. Penicillin G is not effective against infections caused by viruses or parasites (such as worms). Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, penicillin G can cause side effects in some animals. Penicillin G should not be used in animals with known hypersensitivity or allergy to the drug. Penicillin G may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with penicillin G. It is common for animals to develop diarrhea or loose stools following treatment with oral penicillin G because this antibiotic can change the bacterial population of the pet’s intestinal tract. If your pet has diarrhea, notify your veterinarian. Ask if the medication should be changed. How Penicillin G Is Supplied Penicillin G is available in 200,000 units, 250,000 units, 400,000 units, 500,000 units and 800,000 unit capsules. Penicillin G is also available in many different injectable concentrations. Dosing Information Medication should never be administered without first consulting your veterinarian. The typical dose of penicillin G ranges from 10,000 to 25,000 units per pound (20,000 to 50,000 units/kg) two to six times a day. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance

Polysulfated glycosaminoglycan Overview Degenerative joint disease (a form of joint inflammation or arthritis) is very common in animals. Causes include abnormal bone or joint development, instability of the surrounding ligaments and tendons, and damage or injury to the joint. Frequently the cartilage (lubricated

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pads within the joint) is damaged. Polysulfated glycosaminoglycans, also known as PSGAG, belong to a class of drugs known as cartilage protective agents. PSGAG inhibits enzymes that break down cartilage within joints. It reduces inflammation and increases the thickness of joint fluid. PSGAG is related to the anticoagulant (blood thinner) heparin. Polysulfated glycosaminoglycan is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Brand Names and Other Names This drug is registered for use in animals only. Human formulations: None Veterinary formulations: Adequan® (Luitpold) Uses of Polysulfated Glycosaminoglycans PSGAG is used to treat traumatic and non-infectious joint abnormalities and arthritis associated with joint stiffness and limping. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, polysulfated glycosaminoglycans can cause side effects in some animals. Polysulfated glycosaminoglycans should not be used in animals with known hypersensitivity or allergy to the drug. PSGAG should be avoided if a joint infection is present. PSGAG should be avoided around the time of surgery, due to the potential to prolong bleeding (since the drug is related to the anticoagulant heparin). PSGAG should not be used in animals with known coagulation disorders. Polysulfated glycosaminoglycans may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with polysulfated glycosaminoglycans. Such drugs include aspirin, ibuprofen and other non-steroidal anti-inflammatories. Adverse effects associated with PSGAG include joint swelling and inflammation, joint infection and pain. In dogs, problems with blood clotting and bleeding problems have been reported. How Polysulfated Glycosaminoglycans Is Supplied PSGAG is available in injectable form only in 100 mg/ml and 250 mg/ml concentrations. Dosing Information Medication should never be administered without first consulting your veterinarian. For dogs, the dose is 1 to 2.5 mg per pound (2 to 5 mg/kg) in the muscle every 3 to 5 days for three weeks. For cats, the dose is 0.5 to 2.5 mg per pound (1 to 5 mg/kg) in the muscle every 4 days for six doses. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

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Prochlorperazine Overview Prochlorperazine belongs to a class of drugs known as piperazine phenothiazine derivatives. Other related drugs in the class include acepromazine and chlorpromazine. The exact mechanism of action of the phenothiazine derivatives is not completely understood. The drugs work by somehow blocking dopamine receptors in the nervous system and may even inhibit the release of dopamine. These drugs are thought to affect the part of the brain responsible for controlling body temperature, metabolic rate, vomiting, blood pressure and alertness. Compared to other phenothiazines, prochlorperazine has mild sedative effects and strong anti-vomiting effects. Prochlorperazine is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Brand Names and Other Names This drug is registered for use in humans only. Human formulations: Compazine® (SKF), Prochlorperazine® (Wyeth-Ayerst) and various generics. Veterinary formulations: None Uses of Prochlorperazine Prochlorperazine is used to reduce nausea and vomiting. Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, prochlorperazine can cause side effects in some animals. Prochlorperazine should not be used in animals with known hypersensitivity or allergy to the drug. Prochlorperazine should be avoided in animals with glaucoma, low blood pressure or shock. This drug should be used with caution in animals with liver disease, heart disease or older patients. Prochlorperazine may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with prochlorperazine. Such drugs include certain antidiarrheals, antacids, narcotics and metoclopramide. Constipation, sedation and low blood pressure may occur after administration of prochlorperazine. In cases of overdose, prochlorperazine can cause tremors and drooling.

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How Prochlorperazine is Supplied Prochlorperazine is available in 5 mg/ml concentration injectable form in 2ml ampules and 10 ml vials. It is also available as 1 mg/ml syrup in 120 ml bottles. Oral prochlorperazine is available in 5 mg, 10 mg and 25 mg tablets as well as 10 mg, 15 mg and 30 mg sustained release capsules. Prochlorperazine suppositories are also available in 2.5 mg, 5 mg and 25 mg concentrations. Dosing Information Medication should never be administered without first consulting your veterinarian. In dogs and cats, prochlorperazine is dosed at 0.05 to 0.25 mg per pound (0.1 to 0.5 mg/kg) intramuscular or subcutaneous every 6 to 8 hours. In dogs, it can be dosed at 0.5 mg per pound (1 mg/kg) orally every 12 hours. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

Atropine Overview Atropine is administered to block the effect of certain nervous system impulses (acetylcholine) on receptors throughout the body. In animals it is most often used when an animal is undergoing anesthesia for surgery to block the undesirable effects of nervous system stimulation. The involuntary nervous system is divided into the sympathetic (flight or fight response) and parasympathetic branches. In general, these two systems oppose each other. When stimulated, the sympathetic system increases heart rate, blood pressure, and cardiac activity. The pupils dilate and gastrointestinal function reduces. The parasympathetic system, working largely through a nerve called the vagus nerve, slows heart rate, reduces blood pressure, and stimulates gastrointestinal function, salivation, and digestion. Cells contain targets, called receptors, that are stimulated by chemicals released from nerves. In the parasympathetic system, the chemical transmitter released by nerves is acetylcholine and the receptors are called muscarinic receptors. Atropine blocks the muscarinic receptor and thereby inhibits the effect of acetylcholine, reducing the parasympathetic activity of this chemical. Therefore, atropine belongs to the class of drugs known as anti-muscarinic agents. Sometimes they are also called “anti-cholinergics” or “parasympatholytics,” terms that also describe the actions. When the muscarinic part of the parasympathetic nervous system is blocked, the sympathetic system becomes more prominent.

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Atropine is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian. Brand Names and Other Names This drug is registered for use in humans and animals. Atropine is known by the generic name only. There are both human and veterinary formulations available. Uses of Atropine Atropine is used prior to anesthesia for surgery to reduce drooling and respiratory tract secretions. Atropine is often administered with many anesthetic agents to prevent slowing of the heart rate. It is also used to treat dangerously slow heart rates and is an important drug in CPR. Atropine is an antidote for some insecticide (e.g. cholinesterase inhibitors) and mushroom poisonings. Atropine is also used to reduce drooling (salivation), vomiting and nausea. Atropine-like compounds have been used to treat vomiting caused by motion sickness. Atropine-like compounds have been used to treat acute bouts of diarrhea in animals. Atropine is used in the eye to dilate pupils. This can reduce eye pain and prevent complications in various eye diseases. Atropine will antagonize compounds that constrict the airways and cause coughing. Therefore, atropine, and similar compounds can be used in animals that may have difficulty breathing (such as asthma – like conditions). Precautions and Side Effects While generally safe and effective when prescribed by a veterinarian, atropine can cause side effects in some animals. Atropine should not be used in animals with known hypersensitivity or allergy to the drug. It should also not be used if a gastrointestinal obstruction or infection is suspected. Do not use atropine if inflammation of the large bowel is present. Never give atropine to an animal that has been diagnosed as having glaucoma. Atropine may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with atropine. Such drugs include certain antihistamines, meperidine, diazepam, metoclopramide and procainamide. Atropine should be used with caution in animals with rapid heart rates or with impaired kidney, heart or liver function. When the eye formulation for atropine is given, the animal, especially cats, may profusely drool due to the bitter taste of the drug. Some side effects include dry mouth, constipation, central nervous system stimulation (excitement), blurred vision, drowsiness or ataxia (a wobbly walking pattern or gait). Because of the dry mouth, atropine may cause some animals to drink excess water. How Atropine Is Supplied Atropine is available in various injectable concentrations. Atropine is also available in 0.4 mg tablets. Atropine is also available as 1 percent or 2 percent ophthalmic preparation. Dosing Information Medication should never be administered without first consulting your veterinarian. The typical dose for atropine is 0.01 to 0.02 mg per pound (0.022 to 0.044 mg/kg). Usually, atropine is given only by injection. If used as an antidote for certain poisonings, doses up to 1 mg per pound (2 mg/kg) may be required. If used as a treatment for eye disease, one drop in the affected eye every 2 to 24 hours may

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be prescribed. The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.

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713 321 เภสัชกรรมทางสัตวแพทย (Veterinary Pharmacy)

จรีรัตน เอี่ยมสะอาด ภาควิชาเภสัชวิทยาและพิษวิทยา

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คณะสัตวแพทยศาสตร มหาวทิยาลัยขอนแกน