Blood pressure medication propranolol was the first preventive drug approved for the treatment of migraine headaches over 50 years ago. It belongs to the family of beta blockers, but other types of blood pressure drugs can be effective for migraines as well.
Clonidine (Catapres) works not on beta but alpha receptors and has very limited scientific evidence for its efficacy in the prevention of migraines. It is used only if other blood pressure medications are ineffective, cause side effects, or are contraindicated. It is in category C of evidence (possibly effective) of the migraine treatment guidelines issued by the American Academy of Neurology.
Clonidine is also used to treat pain, but the evidence that it really helps is also slim. Anecdotally, it seems to help reduce withdrawal symptoms when stopping opioid (narcotic) drugs.
Besides beta blockers, ACE inhibitors (lisinopril), ACE receptor blockers (candesartan, olmesartan) and calcium channel blockers (flunarizine, verapamil) are probably more effective for the prevention of migraine headaches than clonidine, but most are also in the same category C – possibly effective.
