Antiemetics (Anti-Nausea Drugs) for the Treatment of Migraine

Compazine, Thorazine, and Reglan

Antiemetics, medications used to reduce nausea and vomiting, may be used for the treatment of acute migraine episodes. More than half of those who experience recurrent migraines develop nausea and vomiting during at least some of their migraine attacks. While antiemetics can be effective at easing those symptoms, they can also be helpful for those who experience migraine without them.

Indications

You can use prescription or over-the-counter antiemetics at home if your nausea and vomiting are interfering with your ability to function. Some antiemetics are available as patches, so they can be helpful or if you can't (or aren't up to) swallowing pills.

Children may also receive antiemetics for migraine treatment because nausea and vomiting can be the predominant or only feature of childhood migraines.

Many migraine medications are not safe during pregnancy, and antiemetics are generally safer for the growing baby and pregnant mother than other migraine options.

Prescription antiemetics are often considered the treatment of choice in an emergency setting because they are fast acting and relatively safe. Sometimes, antiemetics are used alone or along with other medications for treatment of status migrainosus, which is a severe migraine lasting for at least 72 hours despite treatment.

Unlike opiods, antiemetics are not addictive, so they are also an option for people who could be at risk of opiod-induced side effects or addiction.

Over-the-Counter

Several over-the-counter medications including Dramamine (dimenhydrinate), Bonine (meclizine), and Benadryl (diphenhydramine), which are often used for motion sickness, can help reduce migraine-associated nausea.

While some people experience improvement of migraine symptoms with an over-the-counter (OTC) option alone, these anti-nausea medications are not as effective as prescription- strength antiemetics when it comes to treating the migraine itself.

These medications are available in oral form. Over-the-counter antiemetics take longer than the prescription strength options to take effect, so they are generally not useful for the treatment of emergency situations such as status migrainosus. Nevertheless, they have almost no side effects and some migraineurs experience improvement of migraine attacks.

How They Help Migraines

Over-the-counter antiemetics do not work in the same way as prescription-strength antiemetics. For example, dimenhydrinate is an antihistamine that reduces nausea by speeding up gastrointestinal movement. Meclizine is an anticholinergic medication that decreases the brain's sensitivity to movement, reducing symptoms of motion sickness.

Prescription antiemetics have a different effect on the body than other migraine treatments and a very different type of action than over-the-counter options. They are dopamine antagonists, which means that they block the receptors that allow dopamine, a neurotransmitter, to function.

how medications block dopamine receptors
Illustration by Emily Roberts, Verywell

Dopamine normally fine-tunes muscle movements, and it also modifies mood and pain. Many dopamine antagonist antiemetics are actually antipsychotics, because excess dopamine action is linked with hallucinations, psychosis, and conditions such as schizophrenia. These medications reduce nausea and vomiting through their dopamine antagonist action in the brain and the gastrointestinal (GI) system.

Antiemetics are not always effective for treating migraines, however, and they can induce distressing short-term and long-term side effects, which include involuntary muscle movements.

Compazine (prochlorperazine)

Compazine (prochlorperazine) is commonly used to treat nausea, and it can be used to treat acute migraine attacks, with or without nausea.

Compazine exerts its antiemetic effects by acting centrally (in the brain) and can be used in the treatment of schizophrenia and the short-term treatment of generalized non-psychotic anxiety. It is also an antihistamine (like Benadryl) and can help reduce vascular headaches.

Compazine is available in tablet form, sustained-released capsules, an oral liquid form, suppository, and can be given intravenously (IV through the vein) or intramuscularly (IM into the muscle).

Potential side effects include drowsiness, dizziness, blurry vision, skin reaction, low blood pressure, and amenorrhea (slowing or absence of menstrual periods). Muscle movements, described as extrapyramidal effects may also occur, including muscle spasms, restlessness, Parkinsonism, or tardive dyskinesia. A rare but potentially life-threatening reaction, neuroleptic malignant syndrome (NMS), causes fever, muscle rigidity, and confusion. 

Thorazine (chlorpromazine)

Thorazine (chlorpromazine) is an antipsychotic used for treatment of schizophrenia and bipolar disorder. It is sometimes used to treat severe nausea, and vomiting.

Like prochlorperazine, it can be given orally, IM, or IV for migraine and nausea relief.

While prochlorperazine is used more often for migraines, and chlorpromazine is used more often for psychosis, they are similar in terms of mechanism of action, efficacy, and side effects.

Reglan (metoclopramide)

Reglan (metoclopramide) blocks dopamine receptors in the GI system. It can help empty your stomach by increasing GI motility (movement).

Reglan is commonly used to treat migraine-related nausea and vomiting, especially in the emergency room or urgent care setting, and is quite effective. It comes in oral, IV, and IM formulations.

While Reglan tends to have fewer side effects than other antiemetics, common side effects include restlessness, tiredness, dizziness, headaches, confusion, problems sleeping, depression, and suicidal thoughts. Like other dopamine antagonists, serious side effects like extrapyramidal symptoms and NMS can occur (very rare).

A Word From Verywell

Antiemetics can be very effective treatments for acute migraine attacks. They are not preventative, and prescription antiemetics are not usually recommended to be taken on a regular basis as a migraine treatment.

If nausea is a major part of your migraines, it is worthwhile to try to figure out whether you experience migraines during your prodromal (pre-headache) phase, during the migraine itself or your postdromal (post-migraine) phase. This can help you and your doctor as you create a treatment plan.

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