Zantryl

Phentermine is a prescription medicine used to help adults lose weight.  It is taken for a limited amount of time by overweight people who are exercising and eating a low-calorie diet.

Phentermine can cause primary pulmonary hypertension, a rare but serious and sometimes fatal side effect. This is a condition where the pressure of the arteries in your lungs increases, causing more pressure on your heart which can lead to heart failure and death. The first symptoms is often shortness of breath or lightheadedness during activity. Other symptoms include:

• Ankle and leg swelling
• Bluish color of the lips or skin 
• Chest pain or pressure, usually in the front of the chest
• Dizziness or fainting spells
• Tiredness
• Increased abdomen size
• Weakness

Common side effects include:

• High blood pressure
• fast heart beats
• insomnia
• dizziness
• rash
• diarrhea
• tremors
• constipation

This is not a complete list of phentermine side effects. Ask your doctor or pharmacist for more information.

While there are no specific phentermine food interactions, you should avoid drinking large amounts of beverages containing caffeine (coffee, tea, colas) or eating large amounts of chocolate while taking phentermine as caffeine can increase the side effects of this medicine.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Phentermine falls into category X. Phentermine should not be used during pregnancy because weight loss offers no potential benefit to a pregnant woman and may result in fetal harm. There are no situations where the benefits of the medication for the mother outweigh the risks of harm to the baby. These medicines should never be used by pregnant women.

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if phentermine crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, a choice should be made whether to stop nursing or stop the use of this medication. Your doctor and you will decide if the benefits outweigh the risk of using phentermine.

• Store phentermine at 20° to 25°C (68° to 77°F).
• Keep this and all medicines out of the reach of children.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Applies to phentermine: compounding powder, oral capsule, oral capsule extended release, oral tablet, oral tablet disintegrating

Cardiovascular

Frequency not reported: Regurgitant cardiac valvular disease, primary pulmonary hypertension, palpitations, tachycardia, elevated blood pressure, precordial pain, ischemic events, angina, myocardial infarction, cardiac failure, cardiac arrest[Ref]

Dermatologic

Frequency not reported: Rash[Ref]

Gastrointestinal

Frequency not reported: Dry mouth, unpleasant taste, diarrhea, constipation, other gastrointestinal disturbances, nausea, vomiting, abdominal cramps[Ref]

Genitourinary

Frequency not reported: Micturition disturbances[Ref]

Hypersensitivity

Frequency not reported: Urticaria[Ref]

Nervous system

Frequency not reported: Overstimulation, restlessness, nervousness, dizziness, euphoria, dysphoria, tremor, headache, fatigue, cerebrovascular events[Ref]

Other

Frequency not reported: Facial edema[Ref]

Psychiatric

Frequency not reported: Insomnia, psychosis, impotence, libido changes, depression, hallucinations[Ref]

Some side effects of Zantryl may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.