dimenhydrinate

Absorption: Well absorbed after oral or IM administration. IV administration results in complete bioavailability.

Distribution: Extensively distributed to tissues.

Metabolism/Excretion: Metabolized by the liver.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(antimotion sickness, antiemetic activity)

ROUTE	ONSET	PEAK	DURATION
PO	15–60 min	1–2 hr	3–6 hr
IM	20–30 min	1–2 hr	3–6 hr
IV	rapid	unknown	3–6 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Some products contain alcohol or tartrazine; in patients with known intolerance.

Use Cautiously in:

Angle-closure glaucoma;
Seizure disorders;
Prostatic hyperplasia.
Geri: ↑risk of anticholinergic adverse reactions in older adults, including falls, delirium, and dementia. Avoid use in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

CV: hypotension, palpitations

Derm: photosensitivity

EENT: blurred vision, tinnitus

GI: anorexia, constipation, diarrhea, dry mouth

GU: dysuria, urinary retention

Local: pain at IM site

Neuro: drowsiness, dizziness, headache, paradoxical excitation (children)

Interactions ⬆ ⬇

Drug-drug:

↑CNS depression with other antihistamines, alcohol, opioid analgesics, and sedative/hypnotics.
May mask signs or symptoms of ototoxicity in patients receiving ototoxic drugs, including aminoglycosides and ethacrynic acid.
↑anticholinergic effects with tricyclic antidepressants, quinidine, or disopyramide.
MAO inhibitors intensify and prolong its anticholinergic effects.

Route/Dosage ⬆ ⬇

PO (Adults ): 50–100 mg every 4 hr (not to exceed 400 mg/day).
PO (Children 6–12 yr): 25–50 mg every 6–8 hr (not to exceed 300 mg/day).
IM IV (Adults ): 50 mg every 4 hr as needed.
IM IV (Children ): 1.25 mg/kg (37.5 mg/m²) every 6 hr as needed (not to exceed 300 mg/day).

Availability ⬆ ⬇

(Generic available)

Tablets: 50 mg^OTC
Chewable tabletsorange flavor: 50 mg^OTC
Solution for injection: 10 mg/mL; 50 mg/mL

Assessment ⬆ ⬇

Assess for signs/symptoms of acute abdomen (nausea, vomiting, bowel sounds, and abdominal pain) before and after administration
Monitor intake and output, and assess for signs of dehydration (excessive thirst, dry skin and mucous membranes, tachycardia, ↑ urine specific gravity, poor skin turgor).
Assess for history of pre-existing conditions that may be aggravated by anticholinergic therapy.

Lab Test Considerations:

Will cause false-negative allergy skin test results; discontinue 72 hr before testing.

Implementation ⬆ ⬇

Do not confuse dimenhydrinate with diphenhydramine. Do not confuse Dramamine (dimenhydrinate) with Dramamine (ginger root) or Dramamine (meclizine).
When used for prophylaxis of motion sickness, administer ≥30 min and preferably 1–2 hr before exposure to conditions that may precipitate motion sickness.
PO: Administer tablets without regard to food.
IM: Inject into well-developed muscle over 2 min; massage well.

IV Administration:

IV Push: Diluent: Dilute 50 mg in 10 mL of 0.9% NaCl for injection.Concentration: 5 mg/mL.
Rate: Inject over 2 min. When used for nausea and vomiting, infuse over 20 min.
Y-Site Compatibility:
- acyclovir
- ampicillin
- caffeine citrate
- calcium gluconate
- cefazolin
- cefotaxime
- ceftazidime
- cefuroxime
- chlorpromazine
- ciprofloxacin
- clindamycin
- cyclosporine
- dexamethasone
- dexmedetomidine
- digoxin
- dobutamine
- fluconazole
- gentamicin
- hydrocortisone
- ketamine
- lorazepam
- magnesium sulfate
- meropenem
- naloxone
- penicillin G
- piperacillin/tazobactam
- tobramycin
- trimethoprim/sulfamethoxazole
- verapamil
Y-Site Incompatibility:
- aminophylline
- diazepam
- furosemide
- heparin
- hydromorphone
- octreotide
- oxytocin
- promethazine
- sodium bicarbonate
- vancomycin

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication. Advise patient to read Patient Information before starting therapy.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking other medications.
May cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to the drug is known.
Inform patient that frequent oral rinses, good oral hygiene, and sugarless gum or candy may minimize dry mouth.
Caution patient to avoid concurrent use of alcohol and other CNS depressants, including opioids.
Pedi: Caution parent or caregiver that children may develop excitation or a paradoxical reaction to dimenhydrinate.
Rep: Advise women of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding. May be used for pregnancy-associated nausea and vomiting. Monitor infants exposed to dimenhydrinate through breast milk for irritability or drowsiness.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇