Drug reference
diphenhydramine
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Drug class
Respiratory (Anti Histamine)
Mechanism of action
Diphenhydramine competes with histamine for the histamine H1 receptor, reversible competitive inhibitor.
Common side effects
- Sedation
- Confusion
- Upset Stomach
Contraindications
- Documented hypersensitivity Lower respiratory tract disease, such as acute asthma (controversial) Premature infants or neonates Nursing mothers Use as local anesthetic To make child <6 years sleep, when used for self-medication
Related conditions
Frequently asked questions
What drug class is diphenhydramine?
diphenhydramine belongs to: Respiratory.
How does diphenhydramine work?
Diphenhydramine competes with histamine for the histamine H1 receptor, reversible competitive inhibitor.
What are the common side effects of diphenhydramine?
Sedation, Confusion, Upset Stomach
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