dimenhydrinate

dimenhydrinate /di·men·hy·dri·nate/ (di″men-hi´drĭ-nāt) an antihistamine used as an antiemetic, particularly in the treatment of motion sickness.

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di·men·hy·dri·nate (dmn-hdr-nt)

n.

An antihistamine used to treat motion sickness and allergic disorders.

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dimenhyDRINATE

[dim′ənhī′drināt]

an antiemetic.

indications It is prescribed in the treatment of nausea and motion sickness.

contraindications Asthma or known hypersensitivity to this drug prohibits its use. It is not given to newborns or lactating mothers.

adverse effects Among the more serious adverse reactions are skin rash, hypersensitivity reactions, and tachycardia. Drowsiness and dry mouth are common.

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dimenhydrinate [di″men-hi´drĭ-nāt]

an antihistamine used as an antinauseant, antiemetic, and antivertigo agent, especially in prevention and treatment of motion sickness, but also in other conditions in which nausea or vertigo may be a feature, administered orally, rectally, or by intramuscular or intravenous injection.

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dimenhydrinate

(dī´menhī´drināt),
n brand names: Calm-X, Dimentabs, Dinate, Dramamine;
drug class: antihistamine, H₁ receptor antagonist;
actions: acts on blood vessels and gastrointestinal and respiratory systems by competing with histamine for H₁ receptor sites; decreases allergic response by blocking histamine;
uses: motion sickness, nausea, vomiting.

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dimenhydrinate

an antihistamine used as an antinauseant and antiemetic.

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dimenhydrinate

Apo-Dimenhydrinate (CA), Dramamine, Dramanate (CA), Gravol (CA), PMS-Dimenhydrinate (CA), Travamine (CA)

Pharmacologic class: Anticholinergic

Therapeutic class: Antiemetic, antivertigo agent

Pregnancy risk category B

Action

Prevents nausea and vomiting by inhibiting vestibular stimulation of chemoreceptor trigger zone and inhibiting stimulation of vomiting center in brain

Availability

Capsules: 50 mg

Capsules (extended-release): 25 mg

Elixir: 12.5 mg/5 ml, 15 mg/5 ml

Injection: 50 mg/ml

Liquid: 12.5 mg/4 ml, 15.62 mg/5 ml

Suppositories: 50 mg, 100 mg

Tablets: 50 mg

Tablets (chewable): 50 mg

⊘Indications and dosages

➣ Prevention and treatment of nausea, vomiting, dizziness, and vertigo

Adults and children ages 12 and older: 50 to 100 mg P.O. q 4 hours (not to exceed 400 mg/day), or 50 to 100 mg P.R. q 6 to 8 hours, or 50 mg I.M. or I.V. q 4 hours p.r.n.

Children ages 6 to 12: 25 to 50 mg P.O. q 6 to 8 hours (not to exceed 150 mg/day), or 25 to 50 mg P.R. q 8 to 12 hours, or 1.25 mg/kg I.M. (37.5 mg/m²) q 6 hours p.r.n.

Children ages 2 to 6: 12.5 to 25 mg P.O. q 6 to 8 hours (not to exceed 75 mg/day)

Contraindications

• Hypersensitivity to drug or tartrazine
• Alcohol intolerance

Precautions

Use cautiously in:
• angle-closure glaucoma, seizure disorders, prostatic hypertrophy.

Administration

• For I.V. use, dilute with dextrose 5% in water or normal saline solution.
• Give each 50-mg I.V. dose over 2 minutes.
☞ Don't administer by I.V. route to premature or low-birth-weight infants. Solution contains benzyl alcohol, which can cause fatal "gasping" syndrome.

Route	Onset	Peak	Duration
P.O.	15-60 min	1-2 hr	3-6 hr
I.V.	Rapid	Unknown	3-6 hr
I.M.	20-30 min	1-2 hr	3-6 hr
P.R.	30-45 min	Unknown	6-12 hr

Adverse reactions

CNS: drowsiness, dizziness, headache, paradoxical stimulation (in children)

CV: hypotension, palpitations

EENT: blurred vision, tinnitus

GI: diarrhea, constipation, dry mouth

GU: dysuria, urinary frequency

Skin: photosensitivity

Other: decreased appetite, pain at I.M. site

Interactions

Drug-drug. Disopyramide, quinidine, tricyclic antidepressants: increased anticholinergic effects

MAO inhibitors: intensified and prolonged anticholinergic effects

Other CNS depressants (such as antihistamines, opioids sedative-hypnotics): additive CNS depression

Ototoxic drugs (such as aminoglycosides, ethacrynic acid): masking of signs or symptoms of ototoxicity

Drug-diagnostic tests. Allergy skin tests: false-negative results

Drug-behaviors. Alcohol use: increased CNS depression

Patient monitoring

• Assess for lethargy and drowsiness.
• Monitor for dizziness, nausea, and vomiting (possible indicators of drug toxicity).

Patient teaching

• To prevent motion sickness, advise patient to take drug 30 minutes before traveling and to repeat dose before meals and at bedtime.
• Instruct patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Caution patient to avoid alcohol and sedative-hypnotics during therapy.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.