Candesartan (Atacand) is a blood pressure medication in the class of ACE receptor blockers (ARBs), none of which are approved for the treatment of migraines. Because they are available in a cheap generic form no pharmaceutical company will spend hundreds of millions of dollars on large trials required for the official FDA approval. This does not mean that unapproved drugs are ineffective, it’s just the evidence is weaker because it is based on small trials. Unfortunately, only four oral drugs are FDA-approved for the prevention of migraines – two beta blockers and two epilepsy drugs (Botox and Aimovig or erenumab are injectable). So most of the preventive drugs we prescribe are “off label”, that is they lack FDA approval.
Candesartan was first shown to work for the prevention of migraine headaches in a 60-patients Norwegian trial published in JAMA in 2003. This was a double-blind crossover trial, which means that half of the patients were first placed on a placebo and then switched to candesartan and the second group started on candesartan and then were switched to placebo. This trial showed that when compared to placebo, 16 mg of candesartan resulted in a very significant reduction in mean number of days with headache, hours with headache, days with migraine, hours with migraine, headache severity index, level of disability, and days of sick leave. Candesartan was very well tolerated – there was no difference in side effects in patients taking the drug and those taking the placebo.
In another trial, the researchers compared candesartan to placebo as well as to propranolol, which is an FDA-approved blood pressure drug for the prevention of migraines. This trial in 72 migraine sufferers compared 16 mg of candesartan with placebo and with 160 mg of propranolol. Candesartan and propranolol were equally effective in reducing migraine days per month and both were significantly more effective than placebo.
One advantage of candesartan over propranolol and other beta blockers is that it does not lower heart rate, which can make exercise difficult. Both can cause fatigue and dizziness due to the lowering of blood pressure, but the weight gain and depression occasionally seen with propranolol does not happen with candesartan. On the other hand, propranolol can sometimes help reduce anxiety.
