dimenhydrinate (Dramamine)
Classes: Antihistamines, 1st Generation; Antiemetic Agents; Antiemetics, Antihistamine
Dosing and uses of Dramamine (dimenhydrinate)
Adult dosage forms and strengths
injectable solution
- 50mg/mL
tablet
- 50mg
tablet, chewable
- 50mg
Prevention of Motion Sickness
50-100 mg PO/IV/IM q4-6hr PRN, 30 minutes before exposure to motion; not to exceed 400 mg/day
Meniere's Disease (Off-label)
25-50 mg PO q8hr for maintenance
50 mg IM for acute attack
Administration
IV: 50 mg in 10 mL NS over 2 minutes
Pediatric dosage forms and strengths
injectable solution
- 50mg/mL
tablet, chewable
- 50mg
tablet
- 50mg
Prevention of Motion Sickness
General dose: 1.25 mg/kg or 37.5 mg/sq.meter IV/IM q6hr; not exceed 300 mg/day
2-6 years old: 12.5-25 mg PO q6-8hr; no more than 75 mg/day
6-12 years old: 12.5-25 mg PO q6-8hr; no more than 150 mg/day
>12 years old: Same as adult dosing
Geriatric dosage forms and strengths
Prevention of Motion Sickness
50-100 mg PO/IV/IM q4-6hr PRN, 30 minutes before exposure to motion; not to exceed 400 mg/day
Meniere's Disease (Off-label)
25-50 mg PO q8hr for maintenance, 50 mg IM for acute attack
Dramamine (dimenhydrinate) adverse (side) effects
Varies in incidence and severity with the individual drug; also individual patients vary in susceptibility
Frequency not defined
Paradoxical CNS stimulation (children and occasionally in adults)
CNS depression
Drowsiness
Sedation ranging from mild drowsiness to deep sleep (most frequent)
Dizziness
Lassitude
Disturbed coordination
Muscular weakness
Restlessness, insomnia, tremors, euphoria, nervousness, delirium, palpitation, seizures is less common
Epigastric distress
Anorexia
Nausea
Vomiting
Diarrhea
Constipation
Cholestasis, hepatitis, hepatic failure, hepatic function abnormality, jaundice is rare
Eczema, pruritus, inflammation, papular rash, erythema on exposed skin may occur with topical formulation
Tachycardia, palpitation ECG changes (eg, widened QRS)
Arrhythmias (eg, extrasystole, heart block)
Hypotension
Hypertension
Dizziness, sedation, and hypotension may occur in geriatric patients
Dryness of mouth, nose, and throat
Dysuria
Urinary retention
Impotence
Vertigo
Visual disturbances
Blurred vision
Diplopia; tinnitus
Acute labyrinthitis
Insomnia
Tremors
Nervousness
Irritability
Facial dyskinesia
Tightness of the chest
Thickening of bronchial secretions
Wheezing
Nasal stuffiness
Sweating
Chills
Early menses
Toxic psychosis
Headache
Faintness
Paresthesia
Agranulocytosis
Hemolytic anemia
Leukopenia
Thrombocytopenia
Pancytopenia
Warnings
Contraindications
Documented hypersensitivity to dimenhydrinate or diphenhydramine
Lower respiratory disease, eg, asthma (controversial)
Preemies and neonates
Nursing women
Cautions
May impair ability to drive or operate heavy machinery
May mask early signs of ototoxicity if given concomitantly with ototoxic drugs (eg, aminoglycosides)
Patients with seizures, angle-closure glaucoma, enlargement of prostate gland, asthma, emphysema, acute hepatic insufficiency
Pregnancy and lactation
Pregnancy category: B
Lactation: Crosses into breast milk, discontinue drug or do not nurse
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Dramamine (dimenhydrinate)
Mechanism of action
Ethanolamine H1 antagonist containing diphenhydramine and 8-chloro-theophylline; pharmacological effects principally result from diphenhydramine moiety, has CNS depressant, anticholinergic, antiemetic, antihistamine, and local anesthetic effects
Antiemetic action may result from inhibiting vestibular stimulation, and inhibiting acetylcholine
Pharmacokinetics
Half-Life: unknown, (half-life of diphenhydramine is about 3.5 hr)
Duration: 3-6 hr
Onset: 20-30 min (IM); 15-30 min (PO); almost immediately (IV)
Bioavailability: Well absorbed
Metabolism: Extensively metabolized in the liver, based on data for diphenhydramine
Excretion: Principally in urine (as metabolites)
Administration
IV Compatibilities
Solution: compatible with most common solvents
Additive: amikacin, amobarbital (at 1 g amobarbital/500 mg dimenhydrinate), calcium gluconate, chloramphenicol sodium succinate, corticotropin, heparin, hydroxyzine, norepinephrine, penicillin G, pentobarbital, phenobarbital, KCl, prochlorperazine, vancomycin, vitamin B/C
Syringe: atropine, codeine, diatrizoate meglumine, diatrizoate sodium, diphenhydramine, droperidol, fentanyl, heparin, hydromorphone, hyoscine, iothalamate meglumine, iothalamate sodium, meperidine, metoclopramide, morphine, pentazocine, perphenazine, ranitidine, scopolamine
Y-site: acyclovir
IV Incompatibilities
Additive: aminophylline (at 1g/L aminophylline and 500 mg/L dimenhydrinate; may be compatible at lower conc), ammonium chloride(?), hydrocortisone (at 500 mg hydrocortisone and 500 mg dimenhydrinate; may be compatible at lower conc), thiopentaL
Syringe: butorphanol, chlorpromazine, glycopyrrolate, hydroxyzine, iodipamide, midazolam, nalbuphine, papaveretum, pentobarbital, prochlorperazine, promazine, promethazine, thiopentaL
IV Administration
50 mg in 10 mL NS over 2 min
Storage
Do not use if cloudy or contains a precipitate
Store at controlled room temp 15-30°C
Protect from freezing