How Do Antiemetic Antihistamines Work?

Antiemetic antihistamines are a class of medications used to treat nausea, vomiting, and dizziness caused by motion sickness. Although vomiting is considered to be a protective reflex action of the body to expel toxic substances in the stomach and gut, antiemetic medications are often necessary to suppress vomiting, especially to prevent dehydration.

Antiemetic antihistamines are administered via oral and intravenous routes; they are most effective if taken before symptoms appear.

Antiemetic antihistamines work in the following ways:

• Vomiting is controlled by the vomiting center in the brain, which is activated by triggers such as strong smell, thoughts, and motion.
• Antiemetic agents bind to the receptors in the vomiting center of the brain stem and block their signaling pathways (that lead to nausea and vomiting), thus reducing the nausea sensation.
• The inner ear plays a key role in maintaining balance; antiemetic antihistamines desensitize the inner ear to the motion of the head and reduce the inner ear's ability to sense motion.
• In addition, they produce a calming effect on the brain that leads to slight drowsiness.

Antiemetic antihistamines are used in conditions such as:

• Motion sickness (nausea caused by motion, especially by travelling in a vehicle)
• Vertigo (a sensation of feeling off balance)
• Meniere's disease (disorder of the inner ear that can lead to dizzy spells and hearing loss)

Common side effects include:

• Headache
• Constipation
• Fatigue
• Drowsiness
• Dizziness (feeling faint, weak, or unsteady)
• Dry mouth
• Loss of appetite
• Other rare side effects include:
• Blurred vision
• Slow heartbeat
• Confusion
• Unusual weakness
• Hallucinations (involve hearing, seeing, feeling, smelling, or even tasting things that are not real)
• Hypertension/hypotension
• Urinary retention

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Drug names include:                              

• Antivert
• Bonine
• Bonine for Kids
• Cyclivert
• Cyclizine
• Dimenhydrinate
• Dramamine
• Dramamine Less Drowsy Formula
• Marezine
• Meclizine
• Meclozine
• Meni D
• VertiCalm