Understanding Anesthesiology - The Global Regional Anesthesia ...

Dimenhydrinate
Class
Antihistamine, antiemetic. In anesthetic practice, used as a second or third line treatment of
post-operative nausea and vomiting (PONV). No role in prevention of PONV.
Mechanism of Action
Dimenhydrinate is a competitive antagonist at the histamine H1 receptor. The antiemetic effects
is related to central anticholinergic actions as well as histamine antagonism in the vestibular
system in the brain.
Dose
50-100 mg IV q4-6h, max. 400 mg/day (adults)
1.25 mg/kg IV q6h (children)
Onset
5 minutes after IV administration
Duration
4-6 hours
Elimination
Hepatic
Effects
CNS
Sedation (which is additive with alcohol and sedative hypnotics), dizziness ,restlessness.
Misc.
May cause dry mouth, blurred vision, difficult urination; more rarely causes acute glaucoma
or worsening of asthma. These side effects reflect its anticholinergic activity which is additive
with other anticholinergics and monoamine oxidase inhibitors (MAOI).
Related Glossary Terms
Antiemetic agents, Chemoreceptor trigger zone, Ondansetron, Post-operative nausea and
vomiting (PONV), Prochlorperazine
Index
Find Term
Chapter 4 - Recovery
Chapter 6 - Drug Finder
Chapter 6 - Antiemetics