Signs of Diphenhydramine (Benadryl) overdose

Description

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 causes 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.

Tests

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

Standard Workup

CBC
Chem 12
EKG
Troponin
BHCG
CT Scan
X-Ray

Treatment

The patient is supported with supplemental oxygen and intravenous fluids. Sedation with benzodiazepines (valium, ativan) is sometimes necessary. Severe intoxications may require a breathing tube. If the symptoms are severe physostigmine can be administered. For more information and help call your local poison center at 1-800-222-1222.