Clonidine stimulates α₂-adrenoceptors in the brain stem which results in reduced sympathetic outflow from the CNS, and a decrease in peripheral resistance, heart rate, BP and renal vascular resistance.

Clonidine is indicated in Anxiety, Cancer pain, Generalized anxiety disorder, Hypertension, Hypertensive crisis, Menopausal flushing, Migraine, Panic disorder, Severe anxiety disorders, Social anxiety disorder

Adults: The dose of Clonidine tablets must be adjusted according to the patient's individual blood pressure response. The following is a general guide to its administration.

Initial Dose: 0.1 mg tablet twice daily (morning and bedtime). Elderly patients may benefit from a lower initial dose.

Maintenance Dose: Further increments of 0.1 mg per day may be made at weekly intervals if necessary until the desired response is achieved. Taking the larger portion of the oral daily dose at bedtime may minimize transient adjustment effects of dry mouth and drowsiness. The therapeutic doses most commonly employed have ranged from 0.2 mg to 0.6 mg per day given in divided doses. Studies have indicated that 2.4 mg is the maximum effective daily dose, but doses as high as this have rarely been employed.

Severe bradyarrhythmia secondary to 2nd- or 3rd-degree AV block or sick sinus syndrome.

Headache, dizziness, drowsiness, dry mouth, constipation, depression, anxiety, nausea, fatigue, anorexia, parotid pain, paraesthesia, delusional perception, sleep disturbances, vivid dreams, impotence and loss of libido, urinary retention or incontinence, orthostatic hypotension, itching or burning sensations in the eye, accommodation disorder, decreased lacrimation, fluid retention, pruritus and rashes (transdermal), bradycardia, other ECG disturbances, heart failure, hallucinations, cramp, Raynaud's syndrome, gynaecomastia, transient abnormalities in LFTs.

Overdose Effects

Symptoms: Lethargy, pupillary constriction, hypotension, hypothermia, bradycardia, decreased or absent reflexes, irritability, miosis, weakness, somnolence (including coma) and resp depression (including apnoea). Paradoxical HTN may occur.

Management: Perform gastric lavage following recent ingestion or admin activated charcoal and/or a cathartic. Supportive treatment may include admin of atropine sulfate for symptomatic bradycardia; IV fluids and/or inotropic sympathomimetic agents for hypotension; vasodilators for HTN. Naloxone may be used as adjunct for clonidine-induced resp depression, hypotension and/or coma.

Patient with cerebrovascular disease, ischaemic heart disease including MI, occlusive peripheral vascular disorders (e.g. Raynaud's disease), or those w/ history of depression. Avoid abrupt withdrawal. Renal impairment. Pregnancy and lactation.

Use in Special Populations

Renal Impairment: Patients with renal impairment may benefit from a lower initial dose. Patients should be carefully monitored. Since only a minimal amount of clonidine is removed during routine hemodialysis, there is no need to give supplemental clonidine following dialysis.

Pregnancy & Lactation

Category C: Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.