Should I take blood pressure pills to ease my migraines?
FOR years I’ve had occasional migraines and treated them with triptans, but recently I started having two a week.
After various preventative treatments, I was prescribed 40mg of the blood pressure medication propranolol twice a day. I’ve not had a migraine since, but suffer from tiredness as a side-effect.
How safe is it to take this long term when I don’t have any blood pressure problems? Also, how does it help my migraines, as my doctor says no one knows? Helen Duffy, by email. The symptoms of migraine — headache, vomiting and sensitivity to light and sound — can have a significant impact on quality of life. That’s why if they occur more than, say, twice weekly, preventative medication may be called for.
Migraine begins with abnormal activity of nerve cells in the brain, which leads to the release of chemicals that cause the blood vessels in the brain to dilate.
Simple over-the-counter painkillers rarely help with migraines. Using painkillers long term can also lead to rebound headaches, when overuse of the medication means the pain returns as soon as the effects wear off, so yet more is needed.
Rebound headaches can also occur with triptans — these aren’t painkillers, but work on symptoms by reducing inflammation and constricting blood vessels. There are three types of drugs for preventing migraines: beta-blockers (a type of blood pressure medication which include propranolol, the drug you’ve been prescribed); antidepressants (usually amitriptyline); and anticonvulsants ( valproate and topiramate are both used).
how propranolol helps prevent migraines is not well understood, but it may be that it blocks receptors in the blood vessel walls, stopping them dilating.
Antidepressants work by interupting communication between the misfiring nerve cells that trigger the migraine, while valproate and topiramate calm the nerve cell irritability that kick-start it. The
goal of preventative therapy is to reduce the frequency and duration of migraine attacks, and it can take weeks to see an improvement. I always insist that patients have a threemonth trial before concluding that a medication has failed — so you’ve been fortunate to have had such a quick response.
Propranolol will not suit everyone. For example, it can lead to a worsening of the symptoms of asthma.
When used to prevent migraine, propranolol is prescribed in much smaller doses than for high blood pressure — patients with migraine are given up to 40mg two to four times day, while with hypertension you may need 160mg twice daily. So it is unlikely to have any significant effect on blood pressure at the dose you’re on.
If you tolerate your dose, there is no danger in taking it for long periods, although I would suggest an annual drug holiday by weaning off (20mg twice daily then 10mg twice daily) for one week, then halving the dose again for a second week, then stopping entirely for a month or two. (But only do this after discussion with your doctor.)
That’s because migraine headaches can improve spontaneously after a period of prevention, or relief may continue at a lower dose.
See your GP every six months for a review, but for now, I’d be relieved to have found something that is safe and effective at ending your migraines.
WRITE to Dr Scurr at Good Health, Daily Mail, 2 Derry Street, London W8 5TT, or email: drmartin@dailymail.co.uk — remember to include your contact details. Dr Scurr cannot enter into personal correspondence. Replies should be taken in a general context and always consult your own GP with any health worries.