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Diphenhydramine — NCLEX Cheat Sheet

1st-gen antihistamine → sedating
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👤 By the CinnaRN Clinical Content Team 🕐 Updated 2026-07-11 🏷️ Pharmacological Therapies 🔖 Free to read, print, and share
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Use this quick-reference guide to spot, treat, and prevent Diphenhydramine on the NCLEX. Keep it handy during review and on exam day!

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Uses

Key facts
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Signs

What to look for
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Avoid

Key facts
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Teach

Teaching points
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Quick Tip

It causes pronounced drowsiness and CNS depression, so it is sedating compared with second-generation antihistamines.

📖 Related Topics

Digoxin ToxicityHeparin TherapyWarfarin TherapyAcetaminophen Poisoning in Children
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