Diphenhydramine

Antihistamine

• -Competes w/histamines at receptor sites
• -Reverses dystonic reactions

• -Allergic reactions
• -Adjunct to epi in treating anaphylaxis
• -Dystonic reactions

• -Glaucoma
• -Acute asthma
• -Lactating mother

• Cardio
• Bradycardia
• Hypotension
• Palpitations

• Neuro
• Headache
• Dizziness
• Drowsiness
• Dilated pupils
• Seizures

• GI
• Dry mouth
• Nausea
• Vomit

• Respiratory
• Wheezing
• Mucus plugs

• 50-100mg slow IV/IO @25mg/min
• Deep IM

1mg/kg slow IV/IO over several mins

• Onset
• IV: 1-5 mins
• IM: 10-15 mins

• Duration
• 3-4 hrs

-May precipitate acute asthma due to drying effect on bronchial mucosa and thickening of secretions.

-May increase ocular pressure in glaucoma due to AS like effect.