Clonidine (Catapres)
Purpose of Medication and Method of Action
Clonidine is used to treat hypertension. It acts by stimulating alpha adrenergic receptors in the brain. This stimulation results in a decrease in sympathetic outflow from the brain to distal arterioles and causes vasodilation and a subsequent reduction in blood pressure.
Side Effects
The most common side effects are: dry mouth (25%), drowsiness (12%), tiredness (6%). When using the cutanoeus patches, an occasional rash would be reported in 5% of patients. A contact dermitis with the product taken orally may occur in as many as 25% of patients. It is most likely to occur from weeks 6-26.
Drug Interactions
Clonidine can potentiate the effects of alcohol and drugs which depress the central nervous system. Patients also taking tricyclic antidepressants may require more clonidine for the desired effect. Use with caution in presence of other drugs which may slow heart rate such as digoxin, beta-adrenergic blockers (metoprolol, labetalol, atenolol), and calcium channel blockers.
Cautions and Contraindications
DO NOT INTERRUPUPT THERAPY SUDDENLY UNDER ANY CIRCUMSTANCES! IF MEDICATION IS TO BE STOPPED THE DOSE SHOULD BE SLOWLY TAPERED OVER 1-2 MONTHS.
Usual Dose
Oral tablets Starting 0.1 mg two times a day increasing to a maximum dose of 2.4 mg each day in divided doses. Patches: apply patch once every seven days.
Patient Medication Information
These information sheets do not list all known side effects of the medications, only the most common side effects. For a complete list of side effects please contact your local pharmacy or the actual drug manufacturing company.