Antihistamines

Respiratory

Mark this drug class

Examples

diphenhydramineloratadine

Prefix / Suffix: No consistent suffix

Physiology

Histamine causes allergic symptoms like sneezing, itching, and mucus production.

Mechanism of Action

They block H1 receptors, reducing allergic responses.

Indications

Allergic rhinitis
Allergic reactions

Side Effects / Adverse Effects

Sedation (first-generation drugs cross the BBB)
Dry mouth (anticholinergic effect)
Drowsiness

Contraindications

Narrow-angle glaucoma
Use caution in elderly

Nursing Considerations

First-generation: avoid driving (causes sedation)
Second-generation preferred for daytime use (less sedating)
Monitor for anticholinergic effects (dry mouth, urinary retention)
Avoid alcohol (increases CNS depression)

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Disclaimer: PharmPal Nurse is for education only and is not medical advice. Do not use it to diagnose, treat, prescribe, or make patient-care decisions; always verify with current drug references, your instructor, facility policy, and a licensed provider. In emergencies, call local emergency services.