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Dr. Chip
Dr. Chip, Board Certified Physician
Category: Medical
Satisfied Customers: 33811
Experience:  20 yrs. in practice, includinge surgery, general medicine, addiction medicine and pain.
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Hi, Wednesday-Sunday of last week I took the antibiotic trimethoprim

Resolved Question:

Hi, Wednesday-Sunday of last week I took the antibiotic trimethoprim for cystitis. I carried on taking my contraceptive pill cilest and had unprotected sex the following monday-wednesday as I did not realize that it may affect the effectiveness of the pill. Does trimethoprim effect cilest? And should I take emergency contraception?
Submitted: 3 years ago.
Category: Medical
Expert:  Dr. Chip replied 3 years ago.
Hi--there is a potential for that antibiotic to lower the efficacy of your birth control pill. For that reason you should consider taking the emergency contraceptive pill but it has to be taken within 72 hours of conception to be effective so you really should first discuss this with a doctor
Customer: replied 3 years ago.

Aren't some emergency contraception useful for up to 5 days

Expert:  Dr. Chip replied 3 years ago.
Yes they can be but it's best to take them within the 72 hour time frame. So if you'd like you can take it now but I still think you should discuss it first with a doctor
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