Print Print
CKS is no longer commissioned by the National Institute for Health and Clinical Excellence (NICE). NICE remains committed to providing a replacement service for CKS and is currently reviewing its options. In the meantime, although CKS content is now not being maintained, it still remains relevant and will continue to be made available. CKS content was generated under a programme of topic creation and update. To check if the topic you are viewing is current or out of date, please refer to the topic publication details by clicking on the 'How up-to-date is this topic?' link in the left hand menu on individual topic pages.

Contraception - Management
Vomiting or diarrhoea while on a combined oral contraceptive (COC): what should be done?

  • A woman who vomits (for any reason) within 2 hours of taking a combined oral contraceptive (COC) should repeat the dose as soon as possible.
  • If vomiting or severe diarrhoea persists for more than 24 hours, the woman should follow the instructions for missed pills, counting each day of vomiting and/or severe diarrhoea as a missed pill:
    • Additional contraceptive cover is required during the illness and for 7 days afterwards.
    • If the illness occurs while taking the last 7 tablets, omit the pill-free period (or inactive tablets) and start the next pill cycle.
Clarification / Additional information
  • The advice offered by the British National Formulary is more cautious [BNF 53, 2007]:
    • 'Vomiting within 2 hours of taking an oral contraceptive or very severe diarrhoea can interfere with its absorption. Additional precautions should therefore be used during (the illness) and for 7 days after recovery. If the vomiting and diarrhoea occurs during the last 7 tablets, the next pill-free interval should be omitted (in the case of everyday [ED] tablets, the inactive ones should be omitted)' [BNF 53, 2007].
Basis for recommendation
  • There is concern that vomiting and/or severe diarrhoea can reduce the efficacy of combined oral contraceptives (COCs) by interfering with its absorption [BNF 53, 2007].
  • These recommendations are those issued by the Faculty of Sexual and Reproductive Healthcare (FSRH), formerly the Faculty of Family Planning and Reproductive Healthcare (FFPRHC) [FFPRHC, 2007b], which reflect those issued by the World Health Organization (WHO) [WHO, 2004a]. The WHO recommendations are based on expert opinion:
    • The WHO expert working group found no direct evidence to address the issue of vomiting and/or severe diarrhoea while using COCs [WHO, 2004a].
    • Although it is uncertain whether the effect of severe vomiting and/or diarrhoea is sufficient to warrant use of the missed pill regimen, the WHO working group considered the effects of vomiting or diarrhoea to be similar to that of missing pills [WHO, 2004a].

© NHS Institute for Innovation and Improvement