All methods with exception of condoms more than 99% effective – if you use it as directed, of course! Combined – Rigevidon has v safe progesterone. Evra is a patch (replace each week for 3 weeks then week free). Nuvaring is monthly ring, less effected by GI problems but more expensive.
Contraindications for any combined product – migraine with aura, first 6 weeks breast feeding. DVT risk related to which progesterone is in combination – risk triples with levonorgestrel (Rigevidon), norethisterone, norgestimate (Cilest) but quadruples for others. But cf risk in pregnancy, more than 10x higher. UKMEC has risk table for family history etc.
Move towards only 4 pill free days – to avoid risk of ovulation if you miss day 1. Ultimately going to 63-84 days continuously (3-4 packs) but potentially confusing as need to stop and start on different days of the week.
Progesterone only pills were just barrier methods, due to effect on mucus. Cerazette (desogestrel) different, inhibits ovulation without other oestrogen effects. Bleeding is quite common in early days. Good for controlling cycle related problems eg menorrhagia, catamenial migraine. Good for young people because continuous. Depot good as lead in for implant (else weight gain as side effect).
Nexplanon is implant, under local, lasts 3 years. But side effects include irregular bleeding.
Enzyme inducers – cbz, phenytoin, topimarate! And st john’s wort! Rifampicin. Lamotrigine is not an inducer, but interacts with COCP/POP so avoid unless no other option, in which case needs dose adjustment and must be continuous method.
Consent to sexual activity often confused! Under 13 cannot consent (so different from medical treatment consent). Consent must be “free agreement” so sleep, coercion, under influence not allowed. Disclosure of child protection concerns is tricky due to fear of disengagement with service.