Management of Contraceptives After Vomiting

General Guidelines for Combined Oral Contraceptives (COCs)

The Centers for Disease Control and Prevention (CDC) recommends that if vomiting occurs within 24 hours of taking a combined oral contraceptive pill, no redosing is necessary, and the patient should continue taking pills daily at the usual time 1, 2
For vomiting continuing for 24 to less than 48 hours, the CDC advises to continue taking pills daily at the usual time and to use backup contraception or avoid sex until 7 consecutive days of correct pill-taking after vomiting stops 1, 2, 3
If vomiting occurred during the last week of hormonal pills, the CDC recommends skipping the hormone-free interval by finishing the current pack and starting a new pack the next day 1, 2, 3
The CDC suggests considering emergency contraception if vomiting occurred during the first week of a new pill pack and the patient had unprotected sex in the previous 5 days 1, 2, 3

The CDC recommends that if vomiting occurs within 3 hours of taking a progestin-only pill, the patient should take another pill as soon as possible, even if feeling uncomfortable 4
For progestin-only pills, the CDC advises using backup contraception or avoiding sex until 2 days after vomiting has resolved 4
The CDC notes that progestin-only pills have a narrower window for effectiveness and that a dose is considered missed if taken more than 3 hours late 4

The CDC recommends that if vomiting occurs within 2-3 hours of taking emergency contraceptive pills, the patient should take another dose as soon as possible 6, 7, 8, 9
The CDC suggests considering the use of antiemetic medication to prevent further vomiting when taking emergency contraceptive pills 6, 7, 8, 9

The CDC notes that peak serum steroid levels from oral contraceptives are reached about 2 hours after administration, and if vomiting occurs before adequate absorption, contraceptive effectiveness may be compromised 4
The CDC advises against assuming that brief vomiting within 24 hours requires redosing for combined oral contraceptives, but notes that this is different for progestin-only pills and emergency contraception 1, 2, 4