ACP: Adjunct treatment of hypersensitivity reaction
Antihistamine with anticholinergic and sedating side effects. Appears to compete with histamine for receptors on effector cells.
Symptoms of overdose are similar to those of atropine toxicity and can include flushing, dilated pupils, hallucinations, confusion, ataxia, seizures, and loss of consciousness. Treatment is primarily supportive.
DiphenhydrAMINE will not abort or terminate a hypersensitivity reaction that is progressing to anaphylaxis; it must not be used in place of EPINEPHrine in these patients.
DiphenhydrAMINE should be used with caution in patients with narrow-angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, symptomatic prostatic hypertrophy, or bladder neck obstruction.
Some evidence exists that suggests diphenhydrAMINE may be heat sensitive, losing some potency after 4+ weeks of storage at temperatures consistently above 40°C. Degraded medication is unlikely to be harmful to patients, but may not carry the same clinical effects, thus requiring higher doses.
DiphenhydrAMINE can potentiate the effects of alcohol, benzodiazepines, and other CNS depressants. Drugs with anticholinergic properties, including tricyclic antidepressants, monoamine oxidase inhibitors, or other antihistamines, may also act synergistically.