Description
Mechanism of Action
Clonidine stimulates alpha-2 receptors in brain stem which results in reduced sympathetic outflow from the CNS and a decrease in peripheral resistance leading to reduced BP and pulse rate. It does not alter normal haemodynamic response to exercise at recommended dosages.
Onset: 2-3 days (transdermal).
Duration: Maintained for 8 hr after removal of system (transdermal).
Absorption: Well absorbed from the GI tract (oral); peak plasma concentrations after 3-5 hr. Absorbed from the skin (transdermal).
Distribution: 20-40% protein bound.
Metabolism: Hepatic: 50% of the dose.
Excretion: Via urine within 24 hr (as 40-60% as unchanged drug), via faeces (20% of the dose); 6-24 hr (elimination half-life), prolonged to 41 hr in renal impairment.
MIMS Class
Other Antihypertensives
ATC Classification
C02AC01 – clonidine; Belongs to the class of imidazoline receptor agonists, centrally-acting antiadrenergic agents. Used in the treatment of hypertension.;
N02CX02 – clonidine; Belongs to the class of other antimigraine preparations.;
S01EA04 – clonidine; Belongs to the class of sympathomimetics used in the treatment of glaucoma.