Diphenhydramine HCl (Benadryl®)

Indications:

• Allergic reaction – standing order
• Dystonic reaction – standing order

Contraindications: Hypersensitivity to diphenhydramine

Precautions: Acute asthma attack

Side Effects:

• Drowsiness
• Sedation
• Disturbed coordination
• Hypotension
• Palpitations
• Tachycardia
• Bradycardia
• Thickening of bronchial secretions
• Dry mouth and throat
• Paradoxical excitement in children
  

Adult Dose:

Standing order:
25 mg – 50 mg

Pediatric Dose:

Standing order:
1 mg/kg – 2 mg/kg

Route:

• IV push (25 mg/minute)
• IM
• IO (alternate route)

Drug Action:

• Blocks histamine1 receptor sites in allergic reactions
• Reverses side effects of dystonic reactions caused by phenothiazines

Class: Antihistamine

Onset: Maximum effects seen in 1 hour to 3 hours

Duration: 6 hours to 12 hours