Midwives may independently prescribe, order and administer this drug.
Competes with histamine for H1-receptor sites on effector cells in the gastrointestinal tract, blood vessels, and respiratory tract; sedative effects are also seen.
Indications and Clinical Use:
Adjunctive therapy in the treatment of anaphylactic reactions related to the administration of drugs, vaccines or sera.
Hypersensitivity to diphenhydramine or any component of the formulation; acute asthma.
Warnings and Precautions:
This drug is for emergency purposes, and its use should be immediately followed by a physician consultation and if out-of-hospital, emergency transport to hospital. Further definitive treatment would be managed by a physician.
Patients should be cautioned about the possibility of CNS depression, which may impair physical or mental abilities.
Use with caution in patients with a history of asthma.
Use with caution in patients with cardiovascular disease (including hypertension and ischemic heart disease).
Use with caution in patients with thyroid dysfunction.
Category L2 – Limited Human Data – Probably Compatible
Chest tightness, hypotension, palpitation, tachycardia, chills, confusion, convulsion, dizziness, fatigue, headache, insomnia, irritability, nervousness, restlessness, sedation, sleepiness, constipation, diarrhea, dry mucous membranes, nausea, throat tightness and vomiting.
Dosage and Administration:
Adult – 50 mg IM
Onset of Action:
Sedative effect – 1-3 hours
Urine (as unchanged drug)