what kind of lawyer would I need for this situation?

I'm sorry but it is not very likely that your friend would have a strong case here against the doctor or another health care provider.  The information concerning how antibiotics can reduce the effectiveness of birth control pills was likely covered in the inserts that came with the prescriptions.  In addition, this information could have been obtained from the pharmacist and many other sources.  In fact, this is commonly known information. Just because your friend did not know this information and just because a doctor or health care provider did not warn your friend, does not constitute medical malpractice.  In order to constitute medical malpractice, there needs to be a breach of the standard of care.  The failure to report this drug interaction (the reduction of the effectiveness of birth control while taking antibiotics) likely does not measure up to that.  However, if you are still interested in discussing this with a lawyer on the phone or in person, you should contact a local medical malpractice or medical negligence attorney.  I am sorry that I do not have better news for your friend but I wish her the best of luck in this endeavor. NOTE: This response is general in nature and should not be considered legal advice.  No attorney-client relationship exists or is formed by this information.