Medication Overuse Headache: When Painkillers Keep the Headache Going

Every week I see someone with a headache most days of the month who is taking painkillers most days of the month, and has been told by nobody that the two are connected. The painkiller helps for a few hours, the headache comes back, another tablet follows. Over months the medicine that used to treat the headache starts to cause it. This is one of the commonest reasons for daily headache, it affects about 1 to 2 in every 100 adults, and it is very treatable once it is recognised.

What is a medication overuse headache?

The International Headache Society defines it as headache on 15 or more days a month in someone who already has a headache condition, most often migraine or tension-type headache, that has developed because of regular overuse of medicines for headache for more than three months. It usually improves once the overuse stops. The everyday name is rebound headache; doctors also call it medicine overuse or analgesic overuse headache. It is not an allergy, and it is not addiction in the usual sense: it is the brain's pain system adapting to a medicine taken too often.

Which medicines cause it, and how often is too often?

It is the number of days a month you take something that matters, not the dose on each day. One paracetamol on 20 days a month carries more risk than eight tablets on two days.

Many over-the-counter headache tablets combine a painkiller with codeine or caffeine, so check the label: those count at 10 days a month. Mixing them counts too: someone taking a triptan on 6 days and co-codamol on 6 days a month is taking acute treatment on 12 days. People who take painkillers every day for back or joint pain can also develop it if they already get headaches.

What does it feel like?

• A headache most days, often already there when you wake up.
• Usually dull and pressing, across the forehead or the whole head, sometimes with neck ache.
• It eases for a few hours after a painkiller and returns as the tablet wears off, so you reach for the next one earlier each time.
• If you have migraine, the migraine attacks still happen on top and respond less well to their usual treatment.
• Tiredness, poor sleep, irritability, low mood and poor concentration are common alongside it.

A headache diary for a month, noting each headache day and each day you took something for it, usually makes the pattern obvious. It is also the first thing a doctor will ask to see.

How to stop it

The treatment is simple to describe and hard to do, which is why it helps to have a plan and someone to check in with. NICE guidance on headaches (CG150) recommends:

1. Stop the overused medicine completely for at least one month. For paracetamol, anti-inflammatories and triptans, stopping all at once works better than cutting down slowly.
2. Codeine and other opioids are different. Do not stop them suddenly on your own if you have been taking them daily: reduce them with a doctor's help, and opioid overuse is a reason to be referred to a specialist.
3. Expect a few worse days. The headache usually gets worse for 2 to 10 days after stopping, sometimes with sickness, poor sleep and restlessness. Plan the start for a quieter week, drink plenty of fluid, keep regular meals and sleep.
4. Treat the headache underneath. Most people with medication overuse headache have migraine or tension-type headache, and a daily preventive treatment, started at the same time, makes withdrawal easier and stops the cycle starting again.
5. Review after 4 to 8 weeks. Bring your diary. Once the overuse has stopped, painkillers or triptans can be used again, but on no more than two or three days a week.

How long does it last?

The headache carries on for as long as the overuse does, so it does not wear off by itself while you keep taking the medicine. After stopping, the worse spell usually lasts 2 to 10 days (longer after opioids), and most people are clearly better within 2 to 8 weeks, often with fewer headache days than they have had for years. Around a third slip back into overuse within a year, usually because the underlying migraine was never properly prevented, which is why the preventive treatment and the "two or three days a week" limit matter as much as the withdrawal itself.

Preventing the headache underneath

A preventive is a treatment taken regularly to reduce how often headaches happen, rather than to treat one once it has started. The options for migraine include:

• Daily preventive tablets from several families of everyday medicines, first used for blood pressure, epilepsy or low mood. A GP can start these and adjust the dose.
• CGRP-targeting medicines, given as an injection under the skin once a month or every three months, or as tablets. On the NHS a headache specialist starts these.
• Preventive injections for chronic migraine (botulinum toxin type A, every 12 weeks) for people with 15 or more headache days a month. NICE recommends that medication overuse is dealt with first, because the treatment works less well while it continues.
• The basics: regular sleep and meals, enough fluid, less caffeine, regular exercise, and attention to stress, all of which reduce headache days on their own.

Tension-type headache is usually managed with the basics and, if needed, a low-dose preventive tablet. A GP can tell the two apart from your history and diary.

Questions people ask

What is a medication overuse headache?

A headache on 15 or more days a month in someone who already gets headaches or migraine, caused by taking painkillers or migraine treatments too often for three months or more. The medicine that used to relieve the headache starts to keep it going. It is also called rebound headache, and it is one of the commonest reasons for daily headache.

Can paracetamol cause medication overuse headache?

Yes. Paracetamol taken on 15 or more days a month for more than three months can cause it, even at normal doses. It is a matter of how many days a month you take it, not how many tablets a day.

Can ibuprofen cause medication overuse headache?

Yes, on the same rule as paracetamol: 15 or more days a month for more than three months. The same applies to aspirin, naproxen and other anti-inflammatory painkillers.

Which painkillers are most likely to cause rebound headaches?

Codeine and other opioid painkillers, including co-codamol, and combination tablets that contain codeine or caffeine, are the most likely, along with triptans: 10 or more days a month is enough. Simple painkillers such as paracetamol and ibuprofen need 15 or more days a month. Opioids carry the highest risk and are the hardest to stop, which is one reason they are not recommended for headache at all.

What does a medication overuse headache feel like?

Usually a dull, pressing headache that is there most days, often already present on waking, that eases for a few hours after a painkiller and returns as it wears off. People with migraine still get their migraine attacks on top. Neck ache, tiredness, poor sleep, low mood and difficulty concentrating are common alongside it.

How long does a medication overuse headache last?

It continues for as long as the overuse does. After stopping the medicine, the headache usually gets worse for a few days, typically 2 to 10 days, and then improves. Most people are clearly better within 2 to 8 weeks. Doctors review progress 4 to 8 weeks after stopping, and a headache diary is the best way to see the change.

How do you stop a medication overuse headache?

By stopping the overused medicine for at least a month. NICE advises stopping painkillers and triptans abruptly rather than tapering them, but codeine and other opioids should be reduced with a doctor's help. Expect a few worse days before it improves. A preventive treatment for the underlying migraine or headache is often started at the same time, and painkillers can be reintroduced afterwards on no more than two or three days a week.

Is a rebound headache the same as a medication overuse headache?

Yes. Rebound headache is the older, everyday name; medication overuse headache is the medical term used by NICE and the International Headache Society.

How many days a week is it safe to take painkillers for headaches?

As a rule of thumb, no more than two or three days a week, and fewer than 10 days a month for triptans or anything containing codeine. If you need painkillers more often than that for headaches, it is a sign the headaches need a different approach, usually a preventive treatment, and worth seeing a GP.

Do gepants cause medication overuse headache?

Current evidence suggests gepants, a newer class of migraine medicine, are much less likely to cause medication overuse headache than triptans or painkillers, and some are used every other day as prevention. The research is still young, so a specialist will still watch how often you take them.

When should I see a doctor about daily headaches?

If you have headaches on more than half the days of the month, take painkillers for them on more than two or three days a week, or rely on codeine, see a GP. Seek urgent help for a sudden severe headache, a headache with fever, stiff neck, rash, weakness, confusion or loss of vision, or a new headache after the age of 50.

Written by Dr Ibrar Ahmed, MBChB MRCP MRCGP PhD PG Dip (Cardiology), GMC 4401399
Specialist interest: Cardiovascular Medicine · OneMedicine, CQC registered clinic