Chronic migraine is defined as a migraine headache that occurs 15 or more days a month, for at least three months. Episodes often last four hours or more.

Chronic migraine is a common condition. Estimates range from around 1 percent to up to 5 percent of people worldwide who experience chronic migraine.

Depression, anxiety, and other issues such as sleep issues are also common among people with chronic migraine.

Treatment may consist of acute, preventive, and complementary therapies. Doctors may also prescribe therapies to address coexisting conditions, such as depression.

Acute treatments are medications taken at the first sign of migraine headache. These treatments don’t prevent migraine, but they offer pain relief during an episode. Most of these drugs must be taken at the first sign of migraine for best results.

The most commonly prescribed drugs for acute treatment are:

Each drug class targets a different site that may contribute to the development of migraines.

At least seven different triptans are presently available. They affect the activity of serotonin. This is an important signaling chemical in the brain. Examples of triptans include:

  • sumatriptan (Imitrex)
  • naratriptan (Amerge)
  • eletriptan (Relpax)

Various drugs are available to help prevent migraine headaches from occurring. In 2010, doctors began prescribing botulinum toxin (Botox) for this purpose.

A 2013 analysis concluded that this therapy reduces monthly attacks by 50 percent or more in some people. But it may also cause adverse effects that could prompt some to discontinue therapy.

Other effective preventive treatments include:

These drugs are less likely to cause intolerable side effects. Some aren’t specifically approved for migraine prevention, though.

A new class, called CGRP antagonists, have been introduced as another option for migraine prevention.

Topiramate for prevention of chronic migraines

Topiramate (Topamax) is a drug originally approved for the treatment of seizures in people with epilepsy. It’s now also approved by the U.S. Food and Drug Administration (FDA) to prevent chronic migraine. The drug can prevent headaches, but side effects may keep some people from taking it on a long-term basis.

Potential side effects include:

  • confusion
  • slowed thinking
  • slurred speech
  • drowsiness
  • dizziness

Nevertheless, researchers suggest it’s effective and reasonably well-tolerated. Similar drugs include valproate and gabapentin.

Beta-blockers for the prevention of migraine

Beta-blockers are considered first-line therapy for the prevention of chronic migraine. Although doctors don’t know why beta-blockers can help, many people find taking them reduces the number of headaches they get.

Although not specifically approved for this use, beta-blockers, such as propranolol, are relatively inexpensive.

They have fewer side effects than some other drugs. They’re ordinarily used to treat anxiety disorders and help control high blood pressure. Other drugs in this class include:

Depression and anxiety disorders are common among people who have migraine. Research suggests that worsening depression is frequently linked to a greater risk of episodic migraines becoming chronic migraine. It’s important for doctors to evaluate and treat people with migraine for the presence of depression or anxiety.

Certain antidepressant medications have been used successfully to treat depression and reduce migraine recurrence. Suitable drugs include older tricyclic antidepressants, such as amitriptyline or imipramine. Botox may also act as an antidepressant, according to emerging research.

In addition to prescription medications, other therapies may offer some relief from chronic migraine. Evidence suggests that certain dietary supplements may be effective to some degree, such as:

Most of these remedies have the advantage of being tolerated well and less expensive than prescription drugs, with fewer known side effects.

Additionally, aerobic exercise and acupuncture have been shown to offer some relief. Other promising alternative therapies include:

Preliminary clinical trials indicate a device pioneered for use in spinal cord injury may prove useful for the prevention of chronic migraine.

Known as an occipital nerve stimulator, the device delivers a weak electrical current directly to the brain through implanted electrodes. Broadly called peripheral neuromodulation, the technique of “shocking” the occipital nerve or other portions of the brain is an extreme, yet promising, new therapy.

Although not yet approved for this use by the FDA, the technology is under investigation for the off-label treatment of chronic migraine.

A new class of medication called CGRP antagonists are under investigation for the prevention of migraine, too. The FDA recently approved enerumab-aooe (Aimovig) for this reason. Several other similar medications are in trials.

While they’re typically tolerated well, the high cost and need for monthly injections means it may be a little while before these medications are widely used.