Antiemetics (phenothiazines)

Examples

These medications are available as injections, tablets, suppositories, or syrup.

How It Works

Promethazine and prochlorperazine stop nausea and vomiting by acting on the brain.

Why It Is Used

Promethazine and prochlorperazine are prescribed to control severe nausea and vomiting. These medications are also used to prevent and control nausea and vomiting caused by chemotherapy.

How Well It Works

Promethazine and prochlorperazine can help stop nausea and vomiting caused by vertigo. When used with other medications, such as serotonin antagonists (for example, ondansetron) and corticosteroids (for example dexamethasone), these medications also help prevent and control nausea and vomiting caused by chemotherapy.

Side Effects

Side effects of these medications may include:

• Drowsiness.
• Dizziness.
• Blurred vision.
• Abnormal menstrual flow.
• Rash.
• Low blood pressure.
• Distorted voluntary movements of the body (dystonic reaction).

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

These medications should not be used by children who weigh less than 20 lb (9.07 kg) or are younger than age 2. Young children seem to be more likely to develop side effects.

Long-term use of these medications may lead to a central nervous system disorder that causes twitching of the face and tongue and involuntary movements of the trunk and limbs (tardive dyskinesia).

In rare cases, acute difficulty making coordinated movements (dystonia)—such as abnormal involuntary movements or posture of the head, eyes, or limbs—may occur. This problem is easily treated and has no long-term effects.

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