Clonidine
- Class: Central alpha-2 agonist
- Used for: high blood pressure
- Say it: KLON-ih-deen
- Forms: tablet, patch
Mnemonic: Clonidine calms from the centre — never stop it suddenly
An alpha-2 agonist acting in the brainstem, reducing outgoing sympathetic traffic. Stop it abruptly and all that suppressed traffic is released at once.
An alpha-2 agonist acting in the brainstem, reducing outgoing sympathetic traffic. Stop it abruptly and all that suppressed traffic is released at once.
Side effects
Common: dry mouth, drowsiness, constipation
Serious: rebound hypertension if stopped suddenly
Typical dose
0.1 mg twice daily, up to 0.6 mg daily
Never stop abruptly: rebound hypertension can be severe. Taper over days.
Check yourself
What happens if Clonidine is stopped abruptly?
- Rebound hypertension, which can be severe
- Nothing of consequence
- A withdrawal seizure
- A prolonged drop in blood pressure
Show answer
A. Rebound hypertension, which can be severe
The suppressed sympathetic outflow returns all at once and overshoots. It is one of the few antihypertensives where simply missing doses is a medical emergency.
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