Diphenhydramine

(Benadryl)

• 1st generation H1 antagonist
• Antimuscarinic, sedating
• More effective as a prevention than a reversal for symptoms
• Only for Histamine; not good for other molecules released from allergic or anaphylactic reactions
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Dimenhydrinate

(Dramamine)

• 1st generation H1 antagonist
• Antimuscarinic, sedating
• More effective as a prevention than a reversal for symptoms
• Only for Histamine; not good for other molecules released from allergic or anaphylactic reactions

• 1st generation H1 antagonist
• Less sedating
• More effective as a prevention than a reversal for symptoms
• Only for Histamine; not good for other molecules released from allergic or anaphylactic reactions

• 1st generation H1 antagonist
• Antimuscarinic, sedating
• More effective as a prevention than a reversal for symptoms
• Only for Histamine; not good for other molecules released from allergic or anaphylactic reactions

2nd generation H1 antagonist

Ionized at physiologic pH; doesn't cross BBB

Less sedation overall

More effective as a prevention than a reversal for symptoms

Only for Histamine; not good for other molecules released from allergic or anaphylactic reactions

Famotidine

(Pepsid)

• H2 Antagonist
• Reduce gastric acid secretion (decr ulcers)
• Usually well tolerated