Benadryl

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GENERIC NAME

Diphenhydramine

BRAND NAME

Benadryl

CLASS

Antihistamine,anticholinergic

MECHANISM OF ACTION

Blocks cellular histamine receptors; decreases vasodilation; decreases motion sickness. Reverses extrapyramidal reactions.

INDICATIONS

Symptomatic relief of allergies, allergic reactions, anaphylaxis, acute dystonic reactions (phenothiazines). Blood administration reactions; used for motion sickness, hay fever.

CONTRAINDICATIONS

Asthma, glaucoma, pregnancy, hypertension, narrow angle glaucoma, infants, patients taking monoamine oxidase inhibitors (MAOIs)

ADVERSE REACTIONS

Sedation. Hypotension, seizures, visual disturbances, vomiting, urinary retention, palpitations, arrhythmias, dry mouth and throat, and paradoxical CNS excitation in children.

NOTES ON ADMINISTRATION

Not used in infants or in pregnancy; Category B. If used in anaphylaxis, will be in conjunction with epinephrine, corticosteroids.

INCOMPATABILITIES/DRUG INTERACTIONS

Potentiates effects of alcohol, and other anticholinergics, may inhibit corticosteroid activity; MAOIs prolong anticholinergic effects of Diphenhydramine.

DOSE/ROUTE;Adult

25-50mg IV, IM, or PO.

DOSE/ROUTE;Pediatric

1-2 mg/kg IV. IO slowly, or IM. If given PO;5mg/kg/24 hours

ONSET OF ACTION

15-30 minutes

PEAK EFFECTS

1 hour

DURATION OF ACTION

3-12 hours.

AZ DRUG BOX SUPPLY RANGE

50 mg.