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A 35-year-old member asked:

how long do 4 hour antihistimines stay in system?

1 doctor answer3 doctors weighed in
Dr. Andrew Murphy
Allergy and Immunology 29 years experience
Day or so: Medications that last for 4 hours or so are probably completely gone with a day or so.
Dr. John Chiu
Dr. John Chiu commented
Allergy and Immunology 57 years experience
Its effects on allergy skin test may last up to 3 days however.
Oct 30, 2013

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Last updated Oct 30, 2013
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