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Benadryl and Heart Palpitations: What Users Say

Heart palpitations: mentioned by 4 users (5.1%)

Based on user experiences from 79 Benadryl reviews, the following table shows the most commonly mentioned side effects.

All user comments are moderated by Drugs.com. Each review is verified for relevance and screened for inappropriate content. Side effects are user-reported and not clinically verified.

drowsiness 15.2%
nausea 8.9%
itching 6.3%
heart palpitations 5.1%
shortness of breath 5.1%
swelling 5.1%
allergic reaction 3.8%
anxiety 3.8%
dry mouth 3.8%
increased heart rate 3.8%

Reviews for Benadryl

  • Jus...
  • Taken for less than 1 month
  • May 9, 2020

For Allergic Reactions "This is an old thread but thought I would share. I was in the hospital in labor. I developed a reaction to the epidural that caused severe itchiness. They gave me something that didn't help, and after several hours of itching, a nurse gave me IV Benadryl. I immediately couldn't breathe and felt like someone kicked me in the chest. I was warm all over, nauseous, and on the edge of passing out. An EKG also showed I had a heart arrhythmia from it. I've taken oral Benadryl in the past with no problems. Now it's on my list of allergies, and I tell every doc I see. Most terrifying experience."

1 / 10
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36 Report
  • Ros...
  • Taken for 2 to 5 years
  • November 24, 2021

For Allergic Reactions "So I've been taking this going on 2 years now, and I regret taking it so long. I even ended up in the ER because my heart wouldn't stop racing, it was over 170. I believe it was due to the Benadryl. I ignored the side effect before I noticed that sometimes when I took it, my heart would beat funny, and it would be hard to catch my breath, but I kept taking it as it stopped my itchy throat, eyes, and mouth. Doctors at the ER found arrhythmia but said everything else looked fine. I stopped taking it, haven't taken it in a week, and I'm still having a racing heart and palpitations. Don't take this stuff long term. I'm in my early 20s and healthy if anyone reading this was curious."

6 / 10
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13 Report
  • Ros...
  • Taken for 2 to 5 years
  • November 24, 2021

For Allergic Reactions "So I've been taking this going on 2 years now, and I regret taking it so long. I even ended up in the ER because my heart wouldn't stop racing, it was over 170. I believe it was due to the Benadryl. I ignored the side effect before I noticed that sometimes when I took it, my heart would beat funny, and it would be hard to catch my breath, but I kept taking it as it stopped my itchy throat, eyes, and mouth. Doctors at the ER found arrhythmia but said everything else looked fine. I stopped taking it, haven't taken it in a week, and I'm still having a racing heart and palpitations. Don't take this stuff long term. I'm in my early 20s and healthy if anyone reading this was curious."

6 / 10
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13 Report

Frequently asked questions

  • gra...
  • March 2, 2016

For Allergic Rhinitis "experienced very low heart rate, palpitations, very disoriented, drowsy after taking only one 25 mg pill."

1 / 10
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11 Report

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Reviews may be edited to correct grammar/spelling or remove inappropriate content. Reviews appearing to come from parties with a vested interest are not published. This information is not intended to endorse any medication and should not replace the expertise and judgment of healthcare professionals.