It is an ethanolamine H1-receptor antagonist.
Mechanism of action:
Dimenhydrinate is thought to inhibit acetylcholine. It inhibits vestibular stimulation. (Vestibular and reticular systems stimulates nausea and vomiting in motion sickness.)
It is used to treat motion sickness. It is also used in Meniere’s disease and some of the other vestibular disturbances. It has been used in the allergic conditions also.
Administration and Dosage:
It can be administered orally, IM or IV. In motion sickness 50 mg of the drug is taken 30 minutes before motion. For vomiting 50-100 mg is taken 4-6 times in 24 hours.
Its duration of action is 2.5-6 hours. It is widely distributed in the body cavities. It can cross the placenta. It is metabolized in liver and excreted through urine.
It may cause drowsiness, headache, dryness of the mouth and respiratory passages.