Potential drug interactions & missed pill rules for women on CHC
Box 3: CHC and potential drug interactions (adapted from https://bnf.nice.org.uk/treatment-summary/contraceptives-interactions.html)
Medications that reduce CHC potency (Enzyme Inducing drugs) | |
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Medications affected by CHC use | |
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Box 4: Missed pill rules for women on CHC (adapted from FSRH guidelines on Incorrect use of combined hormonal contraception December 2018)
1 missed pill | |
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2/more missed pills | |
In first week after pill free interval
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In week 2 or 3 after pill free interval
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Late restarting CHC after pill free interval | |
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*theoretically this applies up to 7 missed pills if the CHC has been taken reliably prior to missed pills.
Review
Women on CHC should be reviewed every year. This follow-up should include: medical eligibility, up to date drug history, method adherence and satisfaction, recording of BP and BMI. It is also important to reiterate when to seek urgent medical review as well as exploring other contraceptive options if they wish to change. Some practices may wish to undertake these reviews without a face-to-face consultation. FSRH and GDG suggest that CHC is appropriate for remote prescribing so long as the above has been checked (e.g. using self-completed checklist).