Dimenhydrinate

dimenhydrinate

(dye men hye' dri nate)

Oral preparations:

Apo-Dimenhydrinate (CAN), Calm-X, Children’s Dramamine, Dimetabs, Dramamine, Gravol (CAN), Triptone

Parenteral preparations:

Dinate, Dramanate, Dymenate, Hydrate

Pregnancy Category B

Drug classes

Anti–motion sickness drug

Antihistamine

Anticholinergic

Therapeutic actions

Antihistamine with antiemetic and anticholinergic activity; depresses hyperstimulated labyrinthine function; may block synapses in the vomiting center; peripheral anticholinergic effects may contribute to anti–motion sickness efficacy.

Indications

·        Prevention and treatment of nausea, vomiting, or vertigo of motion sickness

Contraindications and cautions

·        Contraindicated with allergy to dimenhydrinate or its components, lactation.

·        Use cautiously with narrow-angle glaucoma, stenosing peptic ulcer, symptomatic prostatic hypertrophy, bronchial asthma, bladder neck obstruction, pyloroduodenal obstruction, cardiac arrhythmias, pregnancy.

Available forms

Tablets—50 mg; chewable tablets—50 mg; injection—50 mg/mL; liquid—12.5 mg/4 mL, 12.5 mg/5 mL; 15.62 mg/5 mL

Dosages

ADULTS

Oral

50–100 mg q 4–6 hr PO; for prophylaxis, first dose should be taken 30 min before exposure to motion. Do not exceed 400 mg in 24 hr.

Parenteral

50 mg IM as needed; 50 mg in 10 mL sodium chloride injection given IV over 10 min.

PEDIATRIC PATIENTS 6-12 YR

25–50 mg PO q 6–8 hr, not to exceed 150 mg/24 hr.

PEDIATRIC PATIENTS 2-6 YR

Up to 25 mg PO q 6–8 hr, not to exceed 75 mg/24 hr.

PEDIATRIC PATIENTS < 2 YR

Only on advice of physician; 1.25 mg/kg IM qid, not to exceed 30 mg/24 hr.

NEONATES

Contraindicated.

GERIATRIC PATIENTS

Can cause dizziness, sedation, syncope, confusion, and hypotension in elderly patients; use with caution.

Pharmacokinetics

Route	Onset	Peak	Duration
Oral	15–30 min	2 hr	3–6 hr
IM	20–30 min	1–2 hr	3–6 hr
IV	Immediate	1–2 hr	3–6 hr

Metabolism: Hepatic; T_1/2: Unknown

Distribution: Crosses placenta; enters breast milk

Excretion: Urine

IV facts

Preparation: Dilute 50 mg in 10 mL sodium chloride injection.

Infusion: Administer by direct IV injection over 2 min.

Incompatibilities: Do not combine with tetracycline, thiopental.

Y-site incompatibilities: Do not mix with aminophylline, heparin, hydrocortisone, hydroxyzine, phenobarbital, phenytoin, prednisolone, promethazine.

Adverse effects

·        CNS: Drowsiness, confusion, nervousness, restlessness, headache, dizziness, vertigo, lassitude, tingling, heaviness and weakness of hands; insomnia and excitement (especially in children), hallucinations, seizures, death, blurring of vision, diplopia

·        CV: Hypotension, palpitations, tachycardia

·        Dermatologic: Urticaria, drug rash, photosensitivity

·        GI: Epigastric distress, anorexia, nausea, vomiting, diarrhea or constipation; dryness of mouth, nose, and throat

·        GU: Urinary hesitancy, urinary retention

·        Respiratory: Nasal stuffiness, chest tightness, thickening of bronchial secretions, anaphylaxis

·        Other: In geriatric patients may cause mental status changes, excessive sedation, constipation; in men, may cause urinary retension.

Interactions

Drug-drug

·        Increased depressant effects with alcohol, other CNS depressants

Nursing considerations

Assessment

·        History: Allergy to dimenhydrinate or its components, lactation, narrow-angle glaucoma, stenosing peptic ulcer, symptomatic prostatic hypertrophy, bronchial asthma, bladder neck obstruction, pyloroduodenal obstruction, cardiac arrhythmias

·        Physical: Skin color, lesions, texture; orientation, reflexes, affect; vision examination; P, BP; R, adventitious sounds; bowel sounds; prostate palpation; CBC

Interventions

·        WARNING: Keep epinephrine 1:1,000 readily available when using parenteral preparations; hypersensitivity reactions, including anaphylaxis, have occurred.

Teaching points

·        Take drug as prescribed; avoid excessive dosage.

·        Drug works best if taken before motion sickness occurs.

·        Avoid alcohol; serious sedation could occur.

·        You may experience these side effects: Dizziness, sedation, drowsiness (use caution if driving or performing tasks that require alertness); epigastric distress, diarrhea or constipation (take drug with food); dry mouth (use frequent mouth care, suck sugarless lozenges); thickening of bronchial secretions, dryness of nasal mucosa (try another motion sickness remedy).

·        Report difficulty breathing, hallucinations, tremors, loss of coordination, unusual bleeding or bruising, visual disturbances, irregular heartbeat.

Adverse effects in Italic are most common; those in Bold are life-threatening.