You can question the doctor or nurse practitioner as to why she is making that statement and the reason for her concern, but this standing alone is not sufficient for a medical malpractice case.Medical malpractice is negligence.  Negligence is the failure to exercise due care (that degree of care that a reasonable medical practitioner in the community would have exercised under the same or similar circumstances to prevent foreseeable harm).The doctor or nurse practitioner being prudent in not wanting to increase the dosage of your medication is not medical malpractice.  She may be concerned about the potential for addiction or other complications.