Clonidine is an alpha-2 adrenergic agonist used to treat hypertension and severe cancer pain, among other conditions, and to treat withdrawal symptoms from various substances. It is also used to aid in the diagnosis of pheochromocytoma and to prevent migraines. Clonidine is an imidazole derivate that acts as an agonist of alpha-2 adrenoceptors.
- Mechanism
- Curator reviewed · 9 references
Clonidine is primarily an alpha-2 adrenoceptor agonist which causes central hypotensive and anti-arrhythmogenic effects. The alpha-2 adrenoceptor is coupled to the G-proteins Go and Gi. Gi inhibits adenylyl cyclase and activates opening of a potassium channel that causes hyperpolarization. Clonidine binding to the alpha-2 adrenoceptor causes structural changes in the alpha subunit of the G-protein, reducing its affinity for GDP. Magnesium catalyzes the replacement of GDP with GTP. The alpha subunit dissociates from the other subunits and associates with an effector.
The stimulation of alpha-2 adrenoceptors in the locus coeruleus may be responsible for the hypnotic effects of clonidine as this region of the brain helps regulate wakefulness. Clonidine can also decrease transmission of pain signals at the spine. Finally clonidine can affect regulators of blood pressure in the ventromedial and rostral-ventrolateral areas of the medulla.
- Primary indication
- Clonidine tablets, oral solution and transdermal systems are indicated for the treatment of hypertension alone or in combination with other medications.Curator reviewed · 16 structured indications
- Formula / weight
- C9H9Cl2N3 · 230.094 g/mol (avg)
- First approval
- Canada, 2003 · United States, 1974
- Also known as
- Chlofazoline
- Code names
- M-5041T · SKF 34427 · ST 155 · ST 155-BS
- Brand names
Resolves to
GJSURZIOUXUGAL-UHFFFAOYSA-NSMILESClC1=CC=CC(Cl)=C1NC1=NCCN1What you can answer from here — as of September 13, 2026
Which drugs share a target with Clonidine, and which of those have an active Phase 3 trial?
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