That's a question to ask your doctor or pharmacist. The real question is why bother to take chitosan at all, with no evidence of effectiveness.
http://www.quackwatch.com/04Consumer.../chitosan.html
http://www.quackwatch.com/cgi-bin/mf...ma.html?56#mfs
http://content.health.msn.com/conten...cle/1671.50633
http://content.health.msn.com/conten...cle/1728.54465
TOBF, I would suggest you check out the above articles before spending your hard earned bucks on something that doesn't work - whether or not it affects your other medications.
Again, I'm sorry to be a wet blanket but it really burns me up to see these companies that are 'feeding on the dreams' of people (mostly women) like you and me!
Take care.
MrsJim
265/160/145