Tried several preventives? What comes next on the NHS

If you've worked your way through a few migraine preventives and none has made enough difference, you're not out of options. Over the past few years NICE has approved a group of treatments that target a molecule called CGRP, and they're now used in headache clinics across the country.

What CGRP is, and why it matters

CGRP (calcitonin gene-related peptide) is released during a migraine attack and helps drive the pain and inflammation around the nerves and blood vessels in your head. Most older preventives were designed primarily for something else, such as blood pressure, depression or epilepsy, and happen to help migraine too. Anti-CGRP treatments are the first preventives designed specifically for migraine.

The options

• Injections: erenumab, fremanezumab and galcanezumab. You inject them under the skin yourself, usually once a month, using a pen. Eptinezumab is given as a drip in hospital every 12 weeks.
• Tablets: atogepant, taken once a day, and rimegepant, taken every other day. Rimegepant is only used for prevention in episodic migraine.

Rimegepant can also be used to treat an attack when triptans haven't worked well enough. For chronic migraine, Botox injections are another option at this stage.

Who qualifies

NICE recommends these treatments for adults who have at least four migraine days a month and have already tried at least three preventive medicines that didn't work. That can mean a medicine didn't help enough, the side effects were too much, or you couldn't take it for medical reasons. Your specialist will go through what you've tried and how long you gave each one.

These treatments are usually started by a headache clinic, although some areas now run pharmacist- or nurse-led clinics that can see people more quickly.

How the NHS decides whether it's working

This is the part many people don't know about. After 12 weeks, your treatment is reviewed. To carry on, your migraine days need to have gone down by at least half if you have episodic migraine, or by at least 30% if you have chronic migraine.

That makes a headache diary essential. Your clinic needs to know how many migraine days you had before you started and how many you've had since. Without a record, that judgement comes down to memory, and memory is unreliable when you're in the middle of a bad month. Start recording before your first appointment, not after.

Have your numbers ready for the 12-week review.The free Migrevention diary counts your migraine days before and after you start treatment.

Get the free diary

What to expect

Most people find these treatments easy to take. The most common side effects are constipation and, for the injections, soreness where the needle goes in. They aren't recommended during pregnancy. Some people notice a difference within the first month; for others it takes longer, which is why the review happens at 12 weeks rather than sooner.

Before your appointment

• Medicines: make a list of every preventive you've tried, with the dose, how long you took it and why you stopped.
• Diary: bring at least eight weeks of records showing migraine days, headache days and the days you took painkillers or triptans.
• Painkiller use: check whether you might have medication overuse headache. Dealing with that first can change which treatments are right for you.

Sources: NICE TA973, Atogepant for preventing migraine. NICE technology appraisals for erenumab (TA682), galcanezumab (TA659), fremanezumab (TA764), eptinezumab (TA871) and rimegepant (TA906). NICE TA260, Botulinum toxin type A for chronic migraine.