Antihistamines, or allergy pills, are medications that reduce or block the effects of histamine, a chemical the body produces in response to an allergen.

Whether you have seasonal allergies, indoor allergies, pet allergies, food allergies, or a chemical sensitivity, an allergic response can trigger multiple symptoms, such as:

  • sneezing
  • coughing
  • sore throat
  • runny nose
  • skin rash
  • ear congestion
  • red, itchy, watery eyes

Allergy medication is considered safe when used correctly and can provide quick relief from symptoms, but it’s possible to take too much.

An antihistamine overdose, also called antihistamine poisoning, occurs when there’s too much of the medication in your body. This can be life-threatening, so it’s important that you understand proper dosing to avoid toxicity.