| Question |
Answer |
| 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. |
Ch.18 LTI-MA 509
