clonidin

Clonidin is a prescription medication that acts as an alpha-2 adrenergic receptor agonist. It reduces central sympathetic outflow from the brainstem, leading to decreased peripheral vascular resistance, heart rate, and blood pressure. It is used primarily to treat hypertension, often when other therapies are not suitable, and as an adjunct for attention-deficit/hyperactivity disorder (ADHD) treatment in children when stimulant medications are not appropriate. It is also used to ease withdrawal symptoms from opioids, alcohol, and nicotine, and in some settings to aid sedation or analgesia.

Clonidin is available in oral tablet form and as a transdermal patch. The patch provides continuous delivery for about seven days. Dosage is adjusted based on age, kidney function, and comorbid conditions; abrupt discontinuation can cause rebound hypertension and tachycardia. The drug is metabolized in the liver and excreted in the urine.

Common side effects include drowsiness, fatigue, dizziness, dry mouth, and constipation. Lower blood pressure and bradycardia can occur, particularly with concomitant use of other antihypertensives or beta-blockers. Serious adverse effects are uncommon but include severe hypotension and rebound hypertension after stopping the drug. Clonidin can interact with other central nervous system depressants and certain antidepressants, which may increase sedation or heart rate effects.

Contraindications include hypersensitivity to clonidine; caution is advised in pregnancy and lactation unless clearly indicated. In overdose, supportive care is essential.