Can any medications effect the mirena (levonorgestrel) iud?

Short answer: no. If you mean will any medications make it less effective the answer is no. But certain meds may make your bleeding heavier with the Mirena (levonorgestrel) (warfarin/plavix/lovenox) but these would increase your bleeding if you didn't have a mirena (levonorgestrel). There are no interactions with antibiotics, anti retrovirals, seizure meds, etc. This is one of the reasons i like iuds so much. Very few interactions.