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A 40-year-old member asked:

How much time does it take for benadryl (diphenhydramine) to wear off?

1 doctor answer1 doctor weighed in
Dr. Marino Tavarez
A Verified Doctoranswered
A US doctor answeredLearn more
Benadryl (diphenhydramine): Is usually active in your system for about 4 hours

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A 32-year-old member asked:

How long does it take for liquid Benadryl (diphenhydramine) to wear off?

1 doctor answer2 doctors weighed in
Dr. Jeffrey Rumbyrt
Allergy and Immunology 33 years experience
4-6 hours: Typically, the effect of Benadryl (diphenhydramine) is 4-6 hours. It may be longer in people with liver disease.
Tallassee, AL
A 39-year-old female asked:

Can I take 4 benadryl (diphenhydramine) at one time?

1 doctor answer2 doctors weighed in
Dr. Matt Wachsman
Internal Medicine 37 years experience
Not recommended: that is above the usual dose and will likely produce significant sleepiness. Even one might be a problem with driving. Furthermore, it is very unlikely to produce more benefit than the recommended dose (1, at most 2).
A 34-year-old member asked:

What happens if you take too much benadryl (diphenhydramine)?

1 doctor answer2 doctors weighed in
Dr. Stevan Cordas
Internal Medicine 58 years experience
Benadryl (diphenhydramine): It ususally makes you have a dry mouth and get very sleepy.
Modesto, CA
A 31-year-old female asked:

How many Benadryl (diphenhydramine) pills can I take at one time?

1 doctor answer4 doctors weighed in
Dr. Alvin Lin
Geriatrics 31 years experience
Read label: You can take as many pills as directed by label as often as directed by label. Do not attempt to exceed amount or frequency. Be aware that even over-the-counter medications (and dietary supplements) can interact & even interfere w/prescription medications. So always tell your family physician (and other doctors) everything that you're taking whether prescribed or not.
A 36-year-old member asked:

How much Benadryl (diphenhydramine) is considered too much?

2 doctor answers4 doctors weighed in
Dr. Steven Machtinger
Allergy and Immunology 45 years experience
1 mg per 2 pounds: For children the correct dose is 1 mg/kg ( a kilogram is 2.2 pounds) every six hours as needed. Adults usually take 25-50 mg per dose. If you or your child need more than that you should consult your physician for advice. There are other drugs that are equally effective but cause less or no sedation and have fewer side-effects than Diphenhydramine (benadryl).
Last updated May 22, 2014
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