What advice should I give regarding potential drug interactions with the progestogen-only pill (POP)?
• Some drugs and herbal remedies may interfere with the effectiveness of progestogen-only pills (POPs). • Women taking liver enzyme–inducing drugs should use additional contraception (e.g. condoms) whilst taking the drug and for 4 weeks after finishing the course: • Commonly encountered liver enzyme–inducing drugs are: • Antibiotics: rifampicin and rifabutin. • Anticonvulsants: carbamazepine, oxcarbazepine, phenytoin, phenobarbital, primidone, topiramate. • Herbal remedies: St John’s wort. • Antiretrovirals: drug interactions between certain antiretroviral agents and hormonal contraceptives could alter the safety and effectiveness of both the hormonal contraceptives and the antiretroviral agents. See antiretrovirals. • Antibiotics that do not induce liver enzymes (i.e. all antibiotics except rifampicin and rifamycin) do not reduce the effectiveness of POPs. • Emergency contraception should be considered if sexual intercourse has taken place in the past 5 days and the efficacy of the PO
