Can doxycycline hyclate 100g and/or spironolactone 100g decrease the effectiveness of birth control pill (junel fe 1.5/30)? i take bc daily but had sex without condom (did not finish inside). how much less effective is the pill? should i get plan b?

About antibiotics...: The current thinking is that except for rifampin, other commonly-used antibiotics (such as doxycycline and many others) do not alter the effectiveness of birth control pills. This is likely presuming a person is not sick with vomiting or rapid diarrhea, or some other condition that decreases the absorption of a swallowed pill. One can look up: http://www.ncbi.nlm.nih.gov/pubmed/12063491