Clonidine

ATC code

C02AC01

Therapeutic class

Imidazoline receptor agonist · Centrally acting antiadrenergic agent

Forms

oral tablet

Brand names

Catapresan (ES) · Catapres (US) · Dixarit (UK)

Overall confidence

medium

Regulatory sources consulted

Treatment of all forms of arterial hypertension. It can be administered alone or in combination with other antihypertensive agents.
Clonidine suppression test for the differential diagnosis of pheochromocytoma. · off-label
Treatment of symptoms of post-traumatic stress disorder (PTSD), particularly for improving sleep quality and reducing nightmares. · off-label
Perioperative use to reduce blood loss and improve surgical field quality in functional endoscopic sinus surgery (FESS). · off-label

Major warning · Abrupt discontinuation of treatment can cause rebound hypertensive crisis. Withdrawal should be gradual over 2-4 days. — AEMPS SPC
Major warning · May cause sedation and drowsiness, which are enhanced by alcohol or other CNS depressants. Warn patients about driving or operating machinery. — AEMPS SPC

HighTricyclic antidepressants (e.g., Amitriptyline)N06AA
Mechanism: Pharmacodynamic antagonism at central alpha-2 adrenergic receptors, reducing or nullifying the hypotensive effect of clonidine.
Recommendation: Avoid combination or closely monitor blood pressure. A dose adjustment or an alternative antihypertensive may be necessary.
AEMPS SPC
ModerateBeta-blockers (e.g., Propranolol)C07A
Mechanism: Potentiation of bradycardia. Risk of severe hypertensive crisis if the beta-blocker is withdrawn before clonidine.
Recommendation: If combined therapy must be discontinued, clonidine should be gradually withdrawn several days after the beta-blocker has been stopped.
AEMPS SPC

dizziness · sedation · orthostatic hypotension · dry mouth

bradycardia · AV block · syncope · rebound hypertension

FDA category: C

Not recommended during pregnancy due to insufficient data. It is excreted in breast milk, so breastfeeding is not recommended.

Clonidine for post-traumatic stress disorder: a systematic review of the current evidence.
Marchi M, et al. · Eur J Psychotraumatol · 2024 · Relevance 4/5
Revisión sistemática de 10 estudios (N=569) sobre el uso de clonidina en TEPT. Aunque la evidencia es de baja calidad, muchos estudios reportaron mejoras en la calidad del sueño, reducción de pesadillas y de síntomas del TEPT. Se necesitan ECA de alta potencia para confirmar la eficacia.
Effects of Systemic Clonidine Administration on Blood Loss and Surgical Field Quality in Functional Endoscopic Sinus Surgery.
Gawesh HME, et al. · Acta Otorrinolaringol Esp (Engl Ed) · 2026 · Relevance 4/5
Metaanálisis de 19 ECAs (N=1281) que muestra que la administración de clonidina en cirugía endoscópica funcional de senos paranasales se asocia con una menor pérdida de sangre y una mejor calidad del campo quirúrgico en comparación con placebo, con efectos comparables a la dexmedetomidina.
Update on the diagnosis of the pheochromocytoma.
Achote E, et al. · Hipertens Riesgo Vasc · 2025 · Relevance 3/5
Revisión sobre el diagnóstico del feocromocitoma. Menciona que el test de supresión con clonidina puede ser útil para diferenciar la hipersecreción endógena de falsos positivos en casos de elevaciones moderadas de normetanefrina.