Pharmacokinetic aspects of guanfacine withdrawal syndrome in a hypertensive patient with chronic renal failure.
The unusual observation of a withdrawal syndrome due to guanfacine in a hypertensive patient with chronic renal failure led to a study of the kinetics of the drug in this patient. The principal pharmacokinetic parameters of guanfacine were greatly altered, with extended biotransformation and a decrease in the half-life compared to the values observed in other cases of severe renal insufficiency. Associated treatment with phenobarbital had had a considerable effect, as shown by the results of a further kinetic study 2 months after withdrawal of the phenobarbital. The findings then were in good agreement with reference values which strongly suggests a consequence of the enzyme inducing effect of phenobarbital. Advice about the dosage regimen in such cases is given.
D005260:Female; D016316:Guanfacine; D006146:Guanidines / Q000009:adverse effects* / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000139:chemically induced* / Q000150:complications; D007676:Kidney Failure, Chronic / Q000150:complications*; D007700:Kinetics; D008875:Middle Aged; D010634:Phenobarbital / Q000627:therapeutic use; D010648:Phenylacetates / Q000009:adverse effects* / Q000378:metabolism; D012640:Seizures / Q000139:chemically induced; D013375:Substance Withdrawal Syndrome
D006146:Guanidines; D010648:Phenylacetates; D016316:Guanfacine; D010634:Phenobarbital