Oral Solutions Oral Rehydration Solution

Rx:NaCl 0.3gKCl 0.2gSodiumbicarbonate 0.3gGlucose 2g

The pharmacokinetics and therapeutic values of the substance are as follows:- Glucose facilitates the absorption of sodium ( and hence water ) on a 1:1 molar

basis in the small intestine, although cereal-based formulations may also be used.- Sodium and potassium are needed to replace the body losses of these essential

ions during diarrhea and vomiting.- Citrate or bicarbonate correct the acidosis that occurs as a result of diarrhea and

dehydration. They also enhance the sodium absorption in the small intestine.

1Sometimes, another additive added to the formula such as flavoring and coloring agent, but the ingredients used for flavouring ORS must be among those listed as “Generally Recognized as Safe” for their intended use by the US Food and Drug Administration (FDA) or by the US Flavour Extract Manufacturer’s Association (FEMA). The responsibility for demonstrating the clinical efficacy, safety and chemical stability of such products remains with the manufacturer.

Degredation of ORS-bicarbonate:2The formulation should be stored in a sealed aluminium laminate, under temperature less than 40˚C, the shelf-life of ORS-bicarbonate can easily extend to 2-3 years.If this mixture is exposed to heat and high humidity, an accelerated chemical interaction between the sodium bicarbonate and the glucose may lead to their decomposition, which result in the discoloration of the product from white to yellow and later to brow. This discoloration closely parallels the degree of decomposition of the two chemical and thus provides an easy way of checking the stability of the product for consumption. Whereas a light yellow color indicates a slight decomposition of glucose and sodium bicarbonate, which still allows consumption, the appearance of a dark brown color means that an advanced state of decomposition ( up to 40% or more) has been reached.It's preferable to discard a product in this case.Another way to avoid the decomposition of ORS-bicarbonate in tropical countries is to use chemically treated sodium hydrogen carbonate (encapsulated). However, its use 1 Oral rehydration Salts (ORS) A joint UNICEF/WHO update July 1996 Revised March 2002.2 ORAL REHYDRATION SALTS Planning, establishment and operation WHO, unicef. Reprinted in 1998

may increase the price and make the country dependent for its purchases on a very limited number of manufactures in the world.

Pharmaceutical Forms:They are most commonly available as oral powders (oral rehydration salts) that are reconstituted with water before use, but effervescent tablets and ready-to-use oral solutions are also available.

1Precautions:Oral rehydration salts or effervescent tablets should be reconstituted only with water and at the volume stated. Fresh drinking water is generally appropriate, but freshly boiled and cooled water is preferred when the solution is for infants or when drinking water is not available. The solution should not be boiled after it is prepared. Other ingredients such as sugar should not be added. Unused solution should be stored in a refrigerator and discarded within 24 hours of preparation.

Oral rehydration solutions are not appropriate for patients with gastrointestinal obstruction, oliguric2 or anuric3 renal failure, or when parenteral rehydration therapy is indicated as in severe dehydration or intractable vomiting.

Uses and Administration:Oral rehydration solutions are used for oral replacement of electrolytes and fluids in patients with dehydration, particularly that associated with acute diarrhoea of various aetiologies.The dosage of oral rehydration solutions should be tailored to the individual based on body-weight and the stage and severity of the condition. The initial aim of treatment is to rehydrate the patient, and, subsequently, to maintain hydration by replacing any further losses due to continuing diarrhoea and vomiting and normal losses from respiration, sweating, and urination. Initial rehydration should be rapid, over 3 to 4 hours, unless the patient is hypernatraemic, in which case rehydration over 12 hours is appropriate.

For adults, a usual dose of 200 to 400 mL of oral rehydration solution for every loose motion has been suggested. The dosage for children is 200 mL for every loose motion, and for infants is 1 to 1.5 times their usual feed volume. Normal feeding can continue after the initial fluid deficit has been corrected. Breast feeding should continue between administrations of oral rehydration solution.

1 Martindale.2 Scarcity of urine secretion in relation to the intake of fluids into the body (Medicine).3 Inability to form urine: inability of the kidneys to form urine, so that toxic waste builds up in the blood.

Notes to remember:- ORS first used and proved 1969 recommended and distribute by UNICEF and

WHO.- Using Trisodium citrate dihydrate instead of NaHCO3, to improve the stability of

ORS in heat and humid country.- ORS-citrate results in less stool-out especially in the high output diarrhea

(cholera), and the direct effect of the trisodium citrate is increasing the Intestinal absorption of Na and H2O. But the best choose (ORS-carbonate or ORS-citrate) is based on the stability to be maintained, and the weather or the country.

- The loss of potassium ions in the body hasn't effect on the nerves but actually it will affect the heart pressure before the nerves.

- Acidosis could affects the brain cells and the kidneys.- The pH decreases because of the destruction of the glucose into ketones.

Momer Hakky,