1. Trade Name
  2. Class
    antihistamine; anticholinergic
  3. Mechanism of action
    Blocks cellular histamine receptors; decreases vasodilation; decreases motion sickness. Reverses extrapyramidal reactions
  4. Indications
    Symptomatic relief of allergies, allergic reactions, anaphylaxis, acute dystonic reactions (phenothiazines). Blood administration reactions, used for motion sickness, hay fever.
  5. Contraindications
    Asthma, glaucoma, pregnancy, hypertension, narrow angle glaucoma, infants pts. taking monoamine oxidase inhibitors (MAOIs).
  6. Adverse Reactions
    Sedation, hypotension seizures, visual disturbances, vomiting, urinary retention, palpitations, arrhythmias, dry mouth and throat, and dparadoxical CNS excitation in children.
  7. Drug Interactions
    Potentiates effects of alcohol and other anticholinergics, may inhibit corticosteroid activity; MAOIs prolong anticholinergic effects of diphenhydramine.
  8. How Supplied
    • Tablets: 25, 50mg
    • Capsules: 25, 50 mg
    • Prefilled syringes: 50 or 100 mg vials (IV or IM)
    • Elixer: 12.5 mg/5mL
  9. Dosage and administration
    • Adult: 25-50 mg IM or IV or PO.
    • Pediatric: 1-2 mg/kg IV, IO slowly or IM
    • if given PO: 5 mg/kg/24hrs.
  10. Duration of action
    • Onset: 15-30 minutes
    • Peak effect: 1 hour
    • Duration: 3-12 hours
  11. Special Considerations
    Not used in infants or in pregnancy: category B. If used in anaphylaxis, will be in conjunction with epinephrine, corticosteroids.
Card Set
paramedic pharmacology