Do NOT use Phentermine if:
you are allergic to any ingredient in Phentermine or other sympathomimetics (eg, pseudoephedrine)
you are taking dexfenfluramine, fenfluramine, furazolidone, guanadrel, guanethidine, or have taken a monoamine oxidase inhibitor (MAOI) (eg, phenelzine) in the last 14 days
you have moderate to severe high blood pressure, an overactive thyroid, glaucoma, heart or blood vessel disease, or severe narrowing of the blood vessels
you are in an agitated state, or have a history of substance abuse
Contact your doctor or health care provider right away if any of these apply to you.