Uses

Phentermine (FEN-ter-meen) is used in combination with diet and exercise to help you lose weight.

How to take

Take Phentermine about 30 minutes to 1 hour before a meal.
If you are taking Phentermine once a day, take your dose in the morning. Because this medication may cause sleeplessness, avoid taking a dose late in the day. Take your last dose of Phentermine at least four to six hours before bedtime. Take this medication as prescribed. Do not take it more often or longer than directed. It is usually taken for 8 to 12 weeks. Use in combination with other appetite suppressant medicine is generally not recommended. Consult your doctor before such use.

Side effects

Blurred vision, dizziness, dry mouth, sleeplessness, irritability, stomach upset or constipation may occur the first few days as your body adjusts to the medication. If these effects persist or become bothersome, inform your doctor. Notify your doctor if you experience: chest pain, nervousness, pounding heart, difficulty urinating, mood changes, breathing difficulties, swelling. If you notice other effects not listed above, contact your doctor or pharmacist.
Overdose symptoms may include confusion, diarrhea, nausea, rapid breathing, restlessness, stomach cramps, tremor, vomiting. If overdose is suspected, contact your local poison control center or emergency room immediately.

Precaution

Tell your doctor your complete medical history, especially if you have: high blood pressure, an over-active thyroid, glaucoma, diabetes, emotional problems. This medication can be habit forming and must be used with caution. Alcohol can increase unwanted side effects of dizziness. Limit alcohol use. This medication should be used only when clearly needed during pregnancy. Discuss the risk and benefits with your doctor. This drug may be excreted into breast milk. You may have to stop nursing or stop using this drug. Consult your doctor before breast-feeding.

Drug interactions

Inform your doctor about all the medicines you use, (prescription and nonprescription) especially if you take: Dexfenfluramine, fenfluramine, furazolidone, or MAOIs (eg, phenelzine) because the risk of serious side effects, such as increasing headache, high blood pressure, slow heart rate, elevated temperature, or possibly fatal lung problems, may be increased; Serotonin specific reuptake inhibitors (eg, fluoxetine) because the risk of their side effects may be increased by Phentermine; Guanadrel or guanethidine because their effectiveness may be decreased by Phentermine. Avoid "stimulant" drugs that may increase your heart rate such as decongestants or caffeine. Decongestants are commonly found in over-the-counter cough-and-cold medicines. Do not start or stop any medicine without doctor or pharmacist approval.

Missed dose

If you miss a dose of Phentermine, take it as soon as possible. If it is after 12 PM and you are taking Phentermine 1 time a day, or after 4 PM and you are taking it more than 1 time a day, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses.

Storage

Store Phentermine at room temperature, between 59 and 77 degrees F (15 and 25 degrees C), in a tightly closed container. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Phentermine out of the reach of children and away from pets.