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Date of last update: 10/14/2017.

Forum Name: Gynecology

Question: interaction of birth control pills with allergy medicines

 blackdesert - Mon Jul 18, 2005 2:17 pm

Basically my question is in regards to interactions of birth control pills with other medicines. Do antihistamine allergy relief drugs lessen the effect of birth control pills? (The tablets in question being Piriton tablets containing Chlorpheniramine, and I have been taking Microlite, a combined oral contraceptive). I have been getting conflicting answers and would just like to know for sure, because I had unprotected sex after taking them and it didnt occur to me at the time that it could be a problem. Now that it has occured to me Im really worried it could have lessen the effectiveness and that I could be pregnant.
 Dr. Anthony Solomon - Mon Jul 18, 2005 4:41 pm

Antihistamines, and in particular chlorpheniramine, do not affect the efficacy of oestrogens and progestogens, which are the ingredients of the combined oral contraceptive.

Dr Anthony Solomon
Consultant Physician, Tropical & Genitourinary Medicine

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