Q. Will antibiotics reduce the effect of Oral Contraceptive Pills?

Answered by
Dr. Sonal Prasad
and medically reviewed by iCliniq medical review team.
This is a premium question & answer published on Oct 14, 2016 and last reviewed on: Oct 09, 2018

Hello doctor,

I am using OCP Crisanta 21 for the last six months. Two weeks back, I went for a tooth extraction. So, I took antibiotic Magniclav 625 mg for five days. I had two tablets a day from 15th to 20th of last month. I started my current Crisanta pack on the 16th of last month. My question is can the antibiotic reduce the efficacy of oral contraceptive? If yes, then what is the solution? After how many days of last antibiotic should I need to take birth control pill? Can I solely rely on the contraceptive pill? Or is backup method required? Please explain.



Welcome to icliniq.com.

  • While some antibiotics do induce hepatic enzymes to decrease the efficacy of contraceptive pills, Amoxicillin is not one of them and can be safely used without the fear of contraceptive failure.
  • However, it is important to stick to the contraceptive schedule. If you have taken Crisanta (Ethinyl estradiol) regularly without missing any pills, then you can rely on it completely.
  • Crisanta has to be used regularly as advised. There is no modification in the course or dosage necessary.
  • No backup contraceptive required if you have not missed any pills in this cycle and have been taking Crisanta for more than one cycle.

For further information consult an obstetrician and gynaecologist online --> https://www.icliniq.com/ask-a-doctor-online/obstetrician-and-gynaecologist

Thank you doctor,

If I take Crisanta 21 continuously for 23 or 24 days instead 21days and start a new pack after 7 days of break, then will it work same as 21-7-21 cycle? I mean will it be safe to increase pill taking days to 23 or 24 followed by usual 7 day break? Also, if one takes an I-pill 2 hours before unprotected sex, does she need to take another I-pill after sex? Please clarify.



Welcome back to icliniq.com.

  • Please do not take Crisanta continuously as it will harm you by causing hormonal imbalance. Crisanta is a hormonal drug and too much of it will cause problems.
  • You may opt for 23-7-21 days cycle. But again, do not make it a habit. Surely, you can opt 1 or 2 days of extra pill once in a while without any trouble.
  • In any case, the pill free period should not be more than 7 days. Otherwise, the pills will not be effective for that cycle.
  • However, the efficacy of I-pill is maximum when taken within 72 hours after intercourse and so this regimen should be adhered to whenever possible.

For further information consult an obstetrician and gynaecologist online --> https://www.icliniq.com/ask-a-doctor-online/obstetrician-and-gynaecologist

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