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ANAESTHESIA1. Cis atyracurium is prefferd over atracurium due to advantage of

a. Rapid onsetb. Short duration of actionc. No histamine released. Less cardiodeAns. No histamine release

Difference between cisatracurium and atracurium Cisatracurium is a stereoisomer of atracurium Metabolism of both atracurium and cisatracurium produce laudanosine as metabolite but

cistracurium produces very less amount metabolite

Atracurium is also metabolized by alternative pathway by nospecific esterase Histamine release is very less by cistracurium

Cisatracurium

It is a neuromuscular blocking drug or skeletal muscle relaxant in the category of non-depolarizing neuromuscular-blocking drugs. Used adjunctively in anesthesia to facilities

endotracheal intubation and to provide skeletal muscle relaxation during surgery ormechanical ventilation

It is a bisbenzyltetrahydoisoquinolinium agent with an intermediate duration of action.Cisatracurium is one of the ten isomers of the parent molecule, atracurium Moreover,

cisatracurium represent -15% of the atracurium mixture

Pharmacology

As is evident with the parent molecule, atracurium-cistracurium is also susceptible todegradation by Hofmann elimination and ester hydrolysis as components of the in vivo

metabolic processes

Because Hofmann elimination is a temperature-and plasma pH-dependent process,cisatracuriums rate degradation in vivo is highly influenced by body pH and temperature

just as it is with the prevent molecule, atracurium: thus, an increase in body pH favors the

elimination process, whereas a decrease in temperature slow down the process

One of the metabolites of cistracurium via Hofmann elimination is laudanosine Q 80% of cisatracurium is metabolized eventually to laudanosine and 20% is metabolized

hepatically or excreted renally. 10-15% of the dose is excreted unchanged in the urine

Since hofmann elimination is an organ-independent chemodegradative mechanism, there islittle or no risk to the use of cisatracurium in patients with liver or renal disease when

compared with other neuromuscular blocking agents

Adverse effects

Histamine release-hypotension, reflex tachycardia and cutaneous flusho Unlike the parent, atracurium, cisatracurium affords a much better pharmacological

profile with respect to eliciting

Bronchospasm

Pulmonary compliance

To date, cistracurium has not been reported to elicit bronochospams at doses that are clinically

presecribed

Laudanosine-Epileptic foci

i. Cisatracurium undergoes Hofamnn elimination as a primary route ofchemodegradation: consequently one of the metabolites from this process is

laudanosine, a tertiary amino alkaloid reported to be a modest CNS stimulant

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with epileptogenic activity and cardiovascular effects such a hypotension and

bradycardia

ii. As a ertiary amine, Laudanosine is unionized and readily crosses the blood-brainberrier

iii. Presently, there is little evidence that laudanosine accumulation and relatedtoxicity will likely over be seen with the doses of cisatracurium that are

administered in clinical practive especially given that the plasma concentrations

of laudanosine generated are lower with cistracurium than those seen with

atracurium

2. Laudanosine is metabolite ofa. Cis atracuriumb. Atracuriumc. Pancuroniumd. Gallamine

Ans. B Atracurium

Metabolism of birth atracurium and cistracurium produces laudanosine as metabolic but

cistracurium produces very less amount metabolic

Laudanosine-Epileptic foci

Because atracurium undergoes Hofmannn elimination as a primary route ofchemodegradation, not surprisingly one of the major metabolites from this process is

laudanosis, a tertiary amino alkaloid reported to be a modest CNS stimulant with

epileptogenic activity and cardiovascular effects such a hypotension and bradycardia

The purported hypothesis being that the laudanosine produced from thechemodergradation of parent atracurium would cross the blood-brain barrier in sufficiently

high concentrations that lead to epileptogenic foci

Laudanosine is also a metabolite of cisatracurium which, because of its identical structure toatracurium, undergoes chemodegradation via Hofmann elimination in vivo

Plasma concentrations of laudanosine generated are lower when cisatracurium is used