Indeed, because laudanosine is cleared primarily via renal excretion, a cat study modelling anephric patients went so far as to corroborate that EEG changes, when observed, were evident only at plasma concentrations 8 to 10 times greater than those observed in humans during infusions of atracurium. Thus, the cat study predicted that, following atracurium administration in an anephric patient, laudanosine accumulation and related CNS or cardiovascular toxicity were unlikely - a prediction that correlated very well with a study in patients with kidney failure and undergoing cadaveric renal transplantation. Furthermore, almost a decade later, work by Cardone et al.. confirmed that, in fact, it is the steroidal neuromuscular-blocking agents pancuronium and vecuronium that, when introduced directly into the CNS, were likely to cause acute excitement and seizures, owing to accumulation of cytosolic calcium caused by activation of acetylcholine receptor ion channels. Unlike the two steroidal agents, neither atracurium nor laudanosine caused such accumulation of intracellular calcium. Just over two decades later with availability of atracurium, there is little doubt that laudanosine accumulation and related toxicity will likely never be seen with the doses of atracurium that are generally used.Laudanosine is also a metabolite of cisatracurium that, because of its identical structure to atracurium, undergoes chemodegradation via Hofmann elimination in vivo. Plasma concentrations of laudanosine generated are lower when cisatracurium is used. Pharmacokinetics
Atracurium is susceptible to degradation by Hofmann elimination and ester hydrolysis as components of the in vivo metabolic processes.
Trandolapril has a half-life of about 6 hours, and trandolaprilat has a half life of about 10 h. Trandolaprilat has about eight times the activity of its parent drug. About one-third of trandolapril and its metabolites are excreted in the urine, and about two-thirds of trandolapril and its metabolites are excreted in the feces. Serum protein binding of trandolapril is about 80%. Mode of action
Trandolapril acts by competitive inhibition of angiotensin converting enzyme (ACE), a key enzyme in the renin–angiotensin system which plays an important role in regulating blood pressure. References
External links
Trandolapril Information - rxlist.com (Rxlist.com, The Internet Drug Index)