Diphenhydramine (Benadryl) overdose

About Diphenhydramine (Benadryl) overdose

Diphenhydramine (Benadryl) overdose causes an anticholinergic syndrome. Overdoses can result from deliberate or accidental ingestions. Patients become confused, have rapid heart rates, blurry vision, dry skin and can have seizures. Diphenhydramine is found in many over the counter medications and is most commonly used for allergic reactions, nasal congestion, and as a sleep aid.

Symptoms

Red as a beet (red skin), dry as a bone (the skin is dry), blind as a bat (inability to accommodate the eyes causing blurry vision), mad as a hatter (patients are confused), hot as a hare (fever), seizing like a squirrel (seizures), fast heart rate, tremors, jerking motions, agitation.

Tests & Diagnostics

A history and physical exam will be performed. Tests will be performed to rule out other ingestions or other causes of the signs and symptoms.

Common tests: BHCG, Complete blood count (CBC), Comprehensive metabolic panel (CMP), CT Scan, EKG, Troponin, X-ray.

Conventional treatment summary

The patient is supported with supplemental oxygen and intravenous fluids. Gastric lavage (`pumping the stomach`) and treatment with activated charcoal may be recommended. Sedation with benzodiazepines (Valium, Ativan) is sometimes necessary. Severe intoxications may require a breathing tube. If the symptoms are severe physostigmine may be administered. For more information and help call your local poison center at 1-800-222-1222.

Medical specialties

Medical Toxicology

This page is educational content, not medical advice. Always consult a qualified clinician for diagnosis and treatment of Diphenhydramine (Benadryl) overdose.