Pronunciation: Online audio
weight control agents
Controlled Substance Schedule: IV
Short-term treatment of obesity in conjunction with other interventions (dietary restriction, exercise); used to produce and maintain weight loss in patients with a BMI ≥30 kg/m2 or ≥27 kg/m2 in the presence of other risk factors (diabetes, hypertension, hyperlipidemia).
Decreases hunger by altering the chemical control of nerve impulse transmission in the appetite control center of the hypothalamus.
Appetite suppression with resultant weight loss.
Metabolism and Excretion: Metabolized by the liver.
Half-life: 19–24 hr.
TIME/ACTION PROFILE (appetite suppression)
|PO-resin complex||unknown||unknown||12–14 hr|
For 8-mg tablets, increase to 12–14 hr for 30-mg capsules or 37.5-mg tablets
- Hypersensitivity or known intolerance to sympathomimetic amines
- Cardiovascular disease
- Moderate to severe hypertension
- History of drug abuse
- Concurrent or recent (within 14 days) MAO inhibitor therapy
- Concurrent SSRI antidepressants
- OB: Lactation: Pregnancy or lactation.
Use Cautiously in:
- Mild hypertension
- Diabetes mellitus
- Concurrent use of other weight-loss drugs
- Pedi: Children ≤16 (orally disintegrating tablets) or <12 yr (safety not established).
Adverse Reactions/Side Effects
CNS: CNS stimulation, confusion, dizziness, dysphoria, euphoria, headache, insomnia, mental depression, restlessness
EENT: blurred vision
CV: VALVULAR ABNORMALITIES, hypertension, palpitations, tachycardia
GI: constipation, diarrhea, dry mouth, nausea, unpleasant taste, vomiting
GU: changes in libido, erectile dysfunction
Resp: PULMONARY HYPERTENSION
* CAPITALS indicate life-threatening.
Italics indicate most frequent.
- Concurrent use with MAO inhibitors may result in hypertensive crisis (do not use within 14 days of MAO inhibitors).
- Concurrent use with SSRI antidepressants is not recommended.
- May decrease insulin requirements in diabetic patients.
PO: (Adults) Phentermine hydrochloride tablets or capsules–15–37.5 mg once daily; Phentermine hydrochloride orally disintegrating tablets–15–30 mg once daily; Phentermine resin complex capsules–15–30 mg once daily.
Availability (generic available)
Phentermine hydrochloride tablets: 30 mg, 37.5 mg
Phentermine hydrochloride orally disintegrating tablets (Suprenza): 15 mg, 30 mg
Phentermine hydrochloride capsules: 15 mg, 30 mg, 37.5 mg
Phentermine resin complex capsules: 15 mg, 30 mg
Monitor patients for weight loss and adjust concurrent medications (antihypertensives, antidiabetics, lipid-lowering agents) as needed.
PO: Administer 30 min before meals or as a single dose before breakfast or 10–14 hr before retiring.
- ODT: Gently remove tablet from bottle with dry hands. Immediately place tablet on top of tongue where it will dissolve, then swallow with or without water.
- Instruct patient to take medication as directed. Tolerance to anorectic effect usually develops within a few weeks. If this occurs, phenteramine should be discontinued. The recommended dose should not be exceeded. Medication may need to be discontinued gradually.
- May cause drowsiness. Advise patient to avoid driving or other activities requiring alertness until response to medication is known.
- Caution patient to avoid using alcohol or other CNS depressants with this medication.
- Advise patient to notify health care professional immediately if chest pain, decreased exercise tolerance, fainting, or swelling of the feet or lower legs occurs.
- Caution patient not to use other weight loss products while taking phentermine.
- Advise female patients to avoid use of phentermine during pregnancy or lactation.
Gradual weight loss.