Chlorpromazine (Thorazine) belongs to the phenothiazine family, which includes prochlorperazine (Compazine) and promethazine (Phenergan), drugs used to treat nausea and vomiting. These drugs can relieve not only the accompanying nausea, but the migraine headache as well. The Australian & New Zealand Association of Neurologists recommends chlorpromazine as one of the drugs for the treatment of moderate to severe migraine in an emergency setting.
Chlorpromazine is approved for the treatment of schizophrenia, severe mania and also for nausea, vomiting, severe hiccups, and other conditions. Chlorpromazine is considered to be a stronger antiemetic (anti-nausea) drug than prochlorperazine and promethazine, but it can have more side effects. Side effects include dizziness, drowsiness, but the most unpleasant side effect is severe restlessness and involuntary movements. Some patients describe it as wanting to crawl out of their skin. This side effect usually can be relieved by diphenhydramine (Benadryl). Prolonged use of phenothiazines can lead to persistent involuntary movements, which are extremely unpleasant and do not go away after the medicine is stopped. Higher incidence of side effects is why chlorpromazine should be used for nausea only if milder drugs such as ondansetron (Zofran), metoclopramide (Reglan) and prochlorperazine (Compazine) do not help.
