What is phentermine?
Phentermine is similar to an amphetamine. It stimulates the central nervous system (nerves and brain), which increases your heart rate and blood pressure and decreases your appetite.
Phentermine is used together with diet and exercise to treat obesity, especially in people with risk factors such as high blood pressure, high cholesterol, or diabetes.
Phentermine may also be used for purposes not listed in this medication guide.
Do not use phentermine if you are pregnant or breast-feeding a baby.
You should not use phentermine if you have glaucoma, overactive thyroid, severe heart problems, uncontrolled high blood pressure, advanced coronary artery disease, extreme agitation, or a history of drug abuse.
Do not use this medicine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine. A dangerous drug interaction could occur.
Before taking this medicine
You should not use phentermine if you are allergic to it, or if you have:
- a history of heart disease (coronary artery disease, heart rhythm problems, congestive heart failure, stroke);
- severe or uncontrolled high blood pressure;
- overactive thyroid;
- extreme agitation or nervousness;
- a history of drug abuse; or
- if you take other diet pills.
Do not use phentermine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.
Weight loss during pregnancy can harm an unborn baby, even if you are overweight. Do not use phentermine if you are pregnant. Tell your doctor right away if you become pregnant during treatment.
You should not breast-feed while using this medicine.
To make sure this medicine is safe for you, tell your doctor if you have:
- heart disease or coronary artery disease;
- a heart valve disorder;
- high blood pressure;
- diabetes (your diabetes medication dose may need to be adjusted); or
- kidney disease.