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Antihistamines - Side Effects

unusual occur common physician

Common side effects of antihistamines include drowsiness, dizziness, poor coordination, restlessness, excitability, nervousness, and upset stomach. These problems usually go away as the body adjusts to the drug and do not require medical treatment. Less common side effects, such as dry mouth, nose, and eyes, irritability, difficulty urinating, and blurred vision, also may occur and do not need medical attention unless they do not go away or they interfere with normal activities.

If any of the following side effects occur, check with the physician who prescribed the medicine as soon as possible:

  • rapid, irregular, pounding, or fluttering heartbeat
  • convulsions
  • sweating
  • vomiting
  • fever
  • chills
  • fainting
  • breathing problems
  • hallucinations
  • unusual bleeding or bruising
  • low blood pressure
  • unusual sensitivity to light
  • uncontrolled movements

Other rare side effects may occur. Anyone who has unusual symptoms after taking antihistamines should get in touch with his or her physician.


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over 1 year ago

After having shingles i developed an unusual itching which would move to different places around my stomach, thigh and abdomen area. It itch was so unberable I would scratch myself until I blead. The only thing that would take the itch away was antihistamine tablets. The only thing is that I would develop a very, very short temper. Usually the day after I had taken the antihistamines. I then decided to take a half. I would only take it about every three days or so in order for me to have some kind of a normal life. Strangely enough, I dont get it as often anymore and I even resorted to taken half.

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3 months ago

im taking antihistamine for 7 yrs because of my allergies and i stop suddenly because im gonna have allergy test.and itching of my skin starts like crazy.i wonder if this is from stopping?

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over 2 years ago

I took various antihistamines for 15 years one 4 hour pill before bed to help me breath at night. Then one day I decided to stop taking antihistamines. That's when I developped Ulcerative Collitis, an inflammation of my colon. My question is "has there been any study that shows the side effects of quitting antihistamines after a long daily use?" Thank you

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almost 3 years ago

sometimes get a very slight numb feeling in my mouth when takeing diphendihydramine

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almost 3 years ago

i am always taking anitihistamine(celestamine,aerius)due to my skin allergies..I started getting very moody,very sensitive emotionally..we always argue with my husband because I cannot deal anymore conversation most especially if talking about problems but the worst thing about it is that these antihistamines that i'm taking don't work for me anymore,it seems like my system is getting used to it now

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about 3 years ago

I have a reaction to antihistamines not found in your lists.

Numbness on the right side of the body.

It started suddenly after using PM medications that contain diphendihydramine over an extended period of time.

I was recently prescribed 2 antianxiety medications that had a histamine for sleep and the reaction became numbness and pain on the right side. This is for your info only. Thanks