Benadryl (diphenhydramine) overdose

Description

Diphenhydramine (calmaben) overdose causes the anticholineric syndrome. Overdose can be accidental or intentional. Patients become confused, they have a rapid heartbeat, blurred vision, dry skin and they might have seizures. Diphenhydramine can be found in many medications usually used for allergic reactions, nasal congestion or insomnia.

Symptoms

Skin redness, dry skin, impaired vision, confusion, fever, rapid heartbeat, tremor, restlessness.

Overview

History of disease is being taken and physical examination is being done. Laboratory and radiologic tests are done and they should exclude other causes of the symptoms.

Tests

Complete blood count (CBC), biochemical blood analysis, CT scan, electrocardiogram (ECG/EKG), pregnancy test (beta-HCG), troponin and X-rays.

Additional analyses

Toxicologic urine or blood analysis, creatine phosphokinase (CK).

Specialists

Medical Toxicology

Therapy

The patient is treated with additional oxygen and infusion. Gastric lavage (“stomach pumping”) and activated charcoal may be recommended. Sedation with a benzodiazepine (bensedine) is sometimes necessary. Severe intoxications may require intubation. If symptoms are severe, physostigmine may be prescribed.