Allergic Reaction/Anaphylaxis
Dizziness, drowsiness, urinary retention.
Potentially Lethal Side Effects:
Seizure, Thrombocytopenia, agranulocytosis, hemolytic anemia, anaphylaxis.
Hypersensitivity to H-1 receptor antagonists, acute asthma attack, lower repiratory tract disease.
Mild to Moderate Allergic Reaction:
IV/IM: 25mg
Severe Allergic Reaction/Anaphylaxis:
IV/IM: 50mg
Allergic Reaction/Anaphylaxis
IV/IM: 1mg/kg slow push, prn Max 50mg
- Expect a low BP to be present with anaphylaxis and severe allergic reaction. If BP not decreased, then another cause is likely.
- IM onset may take up to 0.5 hour, IV onset immediate. Both have duration of 4-7 hours.
- In lower airway conditions with increased secretions, diphenhydramine may cause thickening of secretions, thus complicating pre-existing condition. Decreased level of consciousness may cause compromise of a protected airway.