Does isotretinoin affects contraception hormonal pills - Ethinylestradiolum, Drospirenonum? Asking as a pharmacologist not a patient.
My professional knowledge of vitamin A derivatives is limited to preparative aspects and some photochemical properties.
But it seems that the German Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM) provides some information in german and english.
I didn't know whether a link to the search would survive the session, so the link above is just to their website and you would need to search yourself in case you're interested.
Note: I had a look at the Fachinformationen (RTF in German) among the documents "linked".
In this publication, it is very explicitly pointed out that Isotretinoin is a TERATOGEN and efficient contraception therefore is absolutely vital (in the truest sense of the word).
It is suggested that patients use two independent methods of contraception, of which one should be a "barrier method", e.g. the use of condoms.