They may specialize in Palliative Care, Pulmonary, Infectious Disease, Endocrinology, Gastroenterology, Cardiology, Dermatology, Urology, Nephrology, Neurology, Hematology, Oncology, Allergy and Immunology, Rheumatology, or other specialties. Counsels patients about drug regimens and possible side effects or interactions with food supplements, over-the-counter medications, and herbal remedies.