Diphenhydramine

Antihistimine administered after epinephrine in the treatment of anaphylaxis; blocks histimine receptors. When stimulated H1 receptors cause bronchoconstriction and contraction of the gut and H2 receptors produce perpheral vasodilation and secretion of gastric acids.

Diphenhydramine is a potent antihistamine that blocks both histimine receptors (H1 and H2)

Anaphylaxis, allergic reactions, urtcaria, extrapyramidal (EPS) reaction-A response to a drug marked by uncontrolled movements, changes in muscle tone, and abnormal posture.

Benadryl should not be used in the management of lower-respiratory diseases such as asthma.

Hypotension, headache, palpatations, and tachycardia have been known to occur following administration of Benadryl. Sedation, drowsiness, and disturbed coordination are common.

• Standard dose of Benadryl is 25.0-50.0mg
• For antihistimine effects: 12.5-25mg IM followed by 12.5-25mg IV
• Pediatric dose-1mg/kg