Clonidine
Brand: Catapres (US/EU) / Arkamin (IN) / Clonid (BD)
Antihypertensive
Centrally acting α₂-adrenergic agonist
Pharmacokinetics
| Half-life | 12 hours |
| Tmax | 3 h |
| Bioavailability | 75 % (approx) |
| Protein Binding | 20 % |
| Volume of Distribution | 2.1 L/kg (approx) |
| Clearance Route | renal |
| Active Metabolites | no |
| Notes | Well absorbed orally; crosses BBB; 40–60% renal excretion unchanged; may cause rebound hypertension on sudden withdrawal. |
⚠️ Safety & Warnings
Severity: Moderate
Adverse Effects:
Sedation, dry mouth, bradycardia, rebound hypertension, constipation
Contraindications:
Severe bradyarrhythmia, depression
Precautions:
Avoid abrupt discontinuation; caution in elderly and patients with depressive disorders