II. Indications
III. Contraindications
- Concurrent MAO Inhibitor use
- Caution in Narrow Angle Glaucoma
- Caution in Benign Prostatic Hyperplasia with obstruction
IV. Mechanism
- First-generation histamine Antagonist (Sedating Antihistamine, Ethanolamine)
- Competitively blocks H1 Receptors at gastrointestinal Smooth Muscle as well as at Bronchial Smooth Muscle and capillaries
- Effects
- Inhibits Histamine-induced bronchoconstriction
- Inhibits Histamine induced vasodilation and capillary permeability
- Inhibits gastrointestinal Smooth Muscle spasm
V. Dosing: Nausea or Vomiting
- Adults (and children age > 12 years)
- Take 50 to 100 mg PO/IM/IV every 4 to 6 hours as needed (max: 400 mg/day orally, 600 mg/day IV/IM)
- Children (over age 2 years)
- Age 2 to 5 years: Give 12.5 to 25 mg orally every 6 to 8 hours (max: 5 mg/kg/day up to 75 mg/day)
- Age 6 to 12 years: Give 25 to 50 mg orally every 6 to 8 hours (max: 150 mg/day)
VI. Safety
- Pregnancy Category B
- Avoid in Lactation
VII. Adverse Effects
- See Anticholinergic
VIII. Resources
- Dimenhydrinate (DailyMed)
IX. References
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 46-7
- Hamilton (2020) Tarascon Pocket Pharmacopoeia