Diphenhydramine HCL
Benadryl
Class:
Antihistamine.
Antihistamine.
Mechanism of Action:
- Blocks cellular histamine receptors; decreases vasodilation.
- Reverses extrapyramidal ractions.
Indications:
- Symptomatic relief of allergies, allergic reactions, anaphylaxis, acute dystonic reactions (phenothiazines).
- Blood administration reactions.
Contraindications:
Asthma, glaucoma, pregnancy, hypertension, infants.
Asthma, glaucoma, pregnancy, hypertension, infants.
Adverse reactions:
Sedation, hypotension, seizures, visual disturbances, vomiting, palpations, dysrhythmias, dry mouth and throat, paradoxical CNS excitation in children.
Sedation, hypotension, seizures, visual disturbances, vomiting, palpations, dysrhythmias, dry mouth and throat, paradoxical CNS excitation in children.
Drug interactions
Potentiates effects of alcohol and other anticholinergics, may inhibit corticosteroid activity.
Potentiates effects of alcohol and other anticholinergics, may inhibit corticosteroid activity.
Adult Dosage and Administration
25 - 50 mg IM or IV or P.O.
25 - 50 mg IM or IV or P.O.
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Pediatric Dosage and Administration:1-2 mg/kg IV, IO slowly or IM to a max of 50 50 mg.
If given PO: 5mg/kg / 24 hours.
Duration of Action
- Onset: 15-30 minutes.
- Peak effect: 1 hour.
- Duration: 3-12 hours.
Special Considerations:
- Not used in infants or pregnancy.
- Pregnancy safety: Category B
- If used in anaphylaxis, will be in conjunction with epinephrine, steroids.