Guanabenz Disease Interactions

Central alpha-2 adrenoreceptor agonists reduce sympathetic outflow from the central nervous system. Heart rate is decreased, which may lead to or exacerbate sinus bradycardia and atrioventricular block. Therapy with central alpha-2 adrenoreceptor agonists should be administered cautiously in patients with conduction disturbances such as sinus node dysfunction or AV nodal disease.

Central alpha-2 adrenoreceptor agonists may occasionally cause mental depression and should be used cautiously in patients with a history of depression.

Central alpha-2 adrenoreceptor agonists reduce sympathetic outflow from the central nervous system, resulting in decreases in heart rate, peripheral and renovascular resistance, and blood pressure. Therapy with these agents should be administered cautiously in patients with hypotension or conditions that may be exacerbated by decreased blood pressure and perfusion, such as coronary insufficiency, peripheral vascular disease (e.g., Raynaud's syndrome), cerebrovascular disease, or recent myocardial infarction.

Guanabenz is primarily metabolized by the liver. Pharmacokinetic data indicate that the plasma clearance of guanabenz is significantly reduced and its elimination half-life significantly prolonged in patients with liver disease. Therapy with guanabenz should be administered cautiously in patients with impaired hepatic function. Careful monitoring of blood pressure during dosage titration is recommended.

The disposition of orally administered guanabenz is altered modestly in renal impairment. The manufacturer states that the plasma clearance of guanabenz is reduced and its half-life prolonged in patients with impaired renal function, and more so in those on hemodialysis. The clinical significance of these findings is unknown. Careful monitoring of blood pressure during dosage titration is recommended.