MajorAlpha and beta blocker (non-selective β + α1)×Central α2-adrenergic agonist
Updated · Methodology
Mechanism
Clonidine is an α2-agonist that reduces sympathetic tone. Carvedilol blocks β-receptors plus α1-receptors. On abrupt clonidine withdrawal, the α2 effect is lost while carvedilol's β-blockade persists – an 'unopposed' α1 effect develops with a sharp blood pressure rise.
Symptoms
Abrupt clonidine withdrawal causes hypertensive crisis: sharp blood pressure rise, headache, tachycardia, anxiety, sweating. Symptoms appear 18–24 hours after a missed clonidine dose.
Management
For planned clonidine withdrawal, stop carvedilol 3–7 days beforehand, then taper clonidine over 1–2 weeks. Alternative antihypertensive therapy: an ACE-I (enalapril) plus a calcium channel blocker (amlodipine) without clonidine.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
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Sources
- FDA: Clonidine hydrochloride tablet (Alembic Pharmaceuticals Limited) – Prescribing Information section 7 (2012)– ; DailyMed setid 88a8db46-0fc9-48cd-b7cc-ac9c9cdea100
- AEMPS: Ficha técnica: Carvedilol (nº registro 66230), sección 4.5 (2025)– AEMPS, CIMA, nº registro 66230, sección 4.5