- Injection, solution 50 mg/mL
- Tablets 50 mg
- Tablets, chewable 50 mg
- Tablets 50 mg
- Tablets 50 mg
Directly inhibits labyrinthine stimulation for up to 3 h.
Small amounts excreted in breast milk.
20 to 30 min (IM).
3 to 6 h.
Indications and Usage
Prevention and treatment of motion sickness, dizziness, nausea, vomiting.
Treatment of Meniere disease, nausea and vomiting of pregnancy, postoperative nausea, and vomiting.
Use in newborns; hypersensitivity reactions to diphenhydramine or its components (dimenhydrinate or 8-chlorotheophylline).
Dosage and AdministrationMotion Sickness
PO 50 to 100 mg 30 min prior to travel, followed by 50 to 100 mg every 4 to 6 h (max 400 mg/day). IM 50 mg as needed. IV 50 mg in 10 mL of sodium chloride for injection administered over 2 min.Children (6 to 12 y of age)
PO 25 to 50 mg every 6 to 8 h (max 150 mg/day). IM 1.25 mg/kg or 37.5 mg/m 2 4 times daily (max 300 mg/day).Children (2 to 6 y of age)
PO Up to 12.5 to 25 mg every 6 to 8 h (max 75 mg/day). IM 1.25 mg/kg or 37.5 mg/m 2 4 times daily (max 300 mg/day).
- Dimenhydrinate in the injectable form is indicated when the oral form is impractical.
- When administering drug IM, use Z-track method to avoid subcutaneous irritation.
- When administering drug IV, confirm correct catheter or needle placement. Note that this drug should never be given intra-arterially.
Store between 68° and 77°F. Protect from light.
Drug InteractionsAlcohol, CNS depressants
Enhances CNS depressant effects.Aminoglycosides
May mask signs of aminoglycoside-related ototoxicity.Anticholinergic drugs
Causes additive anticholinergic effects.
Ammonium chloride, amobarbital, butorphanol, chlorpromazine, glycopyrrolate, heparin, hydrocortisone, hydroxyzine, midazolam, pentobarbital, phenobarbital, phenytoin, prednisolone, prochlorperazine, promethazine, tetracycline, theophylline, thiopental, trifluoperazine.
Laboratory Test Interactions
May cause false elevation in serum theophylline levels.
Palpitations; hypotension; tachycardia.
Sedation; hallucinations; delirium; drowsiness; confusion, nervousness; restlessness; headache; insomnia; tingling, heaviness and weakness of hands; vertigo; dizziness; lassitude; excitation.
Fixed drug eruption, photosensitivity, rash.
Diminished night vision; decreased color discrimination; exacerbation of narrow-angle glaucoma; blurred vision; diplopia; nasal stuffiness; dryness of nose and throat.
Nausea; vomiting; diarrhea; GI distress; constipation; anorexia; dry mouth.
Prostatic enlargement; difficult or painful urination.
Tightness of chest; wheezing; thickening of bronchial secretions.
Take safety precautions if drowsiness or dizziness occurs. Note paradoxical effect occurs (eg, insomnia, CNS stimulation), and visual or auditory disturbances (eg, blurred vision/tinnitus, hearing loss).
Category B .
Excreted in breast milk.
Safety and efficacy in children younger than 2 y of age not established.
Previous reactions to diphenhydramine.
Special Risk Patients
Use with caution in patients with asthma, bladder neck obstruction, prostatic hypertrophy, narrow-angle glaucoma, pyloroduodenal obstruction, stenosing peptic ulcer, cardiac arrhythmias.
The injection formulation may contain benzoyl alcohol. Benzyl alcohol has been associated with a fatal “gasping syndrome” in premature infants and infants of low birth weight.
Since dimenhydrinate is capable of masking ototoxic symptoms, use with caution in conjunction with certain antibiotics that may cause ototoxicity.
Drowsiness, hallucinations, convulsions, coma, respiratory depression, death.
- Advise patient to take medication 30 to 60 min before activity that may produce nausea or motion sickness.
- Instruct patient to report these symptoms to health care provider: drowsiness, nervousness, dry mouth, insomnia, constipation, blurred vision.
- If dimenhydrinate is being given as antiemetic, instruct patient to report nausea and vomiting to the health care provider.
- Instruct patient to take sips of water frequently, suck on ice chips or sugarless hard candy, or chew sugarless gum if dry mouth occurs and to relieve constipation with increased fiber in diet and good hydration.
- Caution patient to avoid intake of alcoholic beverages or other CNS depressants.
- Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.
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