Phentermine is a sympathomimetic amine anorectic sold in the U.S. under 4 brand and generic names, for obesity. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
From the FDA label for Fastin (application NDA017352). Other phentermine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Dosage should be individualized to obtain an adequate response with the lowest effective dose. (2.1) Late evening administration should be avoided (risk of insomnia). (2.1) Phentermine hydrochloride can be taken with or without food. (2.1) Limit the dosage to 15 mg daily for patients with severe renal impairment (eGFR 15 to 29 mL/min/1.73m 2 )- ( 2.2 ) 2.1Exogenous Obesity Dosage should be individualized to obtain an adequate response with the lowest effective dose. The usual adult dose is one capsule (37.5 mg) daily as prescribed by the physician, administered before breakfast or 1 to 2 hours after breakfast for appetite control. The usual adult dose is one tablet (37.5 mg) daily, as prescribed by the physician, administered before breakfast or 1 to 2 hours after breakfast. The dosage may be adjusted to the patient’s need. For some patients, half tablet (18.75 mg) daily may be adequate, while in some cases it may be desirable to give half tablets (18.75 mg) two times a day. Phentermine is not recommended for use in pediatric patients ≤ 16 years of age. Late evening medication should be avoided because of the possibility of resulting insomnia. 2.2 Dosage in Patients With Renal Impairment The recommended maximum dosage of phentermine hydrochloride is 15 mg daily for patients with severe renal impairment (eGFR 15 to 29 mL/min/1.73m 2 ). Avoid use of phentermine hydrochloride in…
The following adverse reactions are described, or described in greater detail, in other sections: • Primary pulmonary hypertension [ see Warnings and Precautions ( 5.2 ) ] • Valvular heart disease [ see Warnings and Precautions ( 5.3 ) ] • Effect on the ability to engage in potentially hazardous tasks [ see Warnings and Precautions ( 5.5 ) ] • Withdrawal effects following prolonged high dosage administration [ see Drug Abuse and Dependence ( 9.3 ) ] The following adverse reactions to phentermine have been identified: Cardiovascular Primary pulmonary hypertension and/or regurgitant cardiac valvular disease, palpitation, tachycardia, elevation of blood pressure, ischemic events. Central Nervous System Overstimulation, restlessness, dizziness, insomnia, euphoria, dysphoria, tremor, headache, psychosis. Gastrointestinal Dryness of the mouth, unpleasant taste, diarrhea, constipation, other gastrointestinal disturbances. Allergic Urticaria. Endocrine Impotence, changes in libido. Adverse events have been reported in the cardiovascular, central nervous, gastrointestinal, allergic, and endocrine systems. To report SUSPECTED ADVERSE REACTIONS, contact Sunrise Pharmaceutical, Inc. at 732-382-6085 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Typical price | |
|---|---|---|---|---|---|---|---|
| 1 | 70/100 | Prescription | Capsule | Generic | $3 | View → | |
| 2 | Not yet rated | Prescription | Capsule | Generic | $3 |
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| U40 | 37.5 mg | white | capsule | — |
| N;1 | 15 mg | gray | capsule | — |
| E;16 | 37.5 mg | white | oval | — |
| K;1 | 8 mg | white, blue | freeform | — |
| K;29 | 37.5 mg | white, blue | capsule | — |
A combination is a different drug — different dosing, different warnings. It is listed here so you can find it, not so you can substitute it.
From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
History of cardiovascular disease (e.g., coronary artery disease, stroke, arrhythmias, congestive heart failure, uncontrolled hypertension) • During or within 14 days following the administration of monoamine oxidase inhibitors • Hyperthyroidism • Glaucoma • Agitated states • History of drug abuse • Pregnancy [ see Use in Specific Populations ( 8.1 ) ] • Nursing [ see Use in Specific Populations ( 8.3 ) ] • Known hypersensitivity, or idiosyncrasy to the sympathomimetic amines History of cardiovascular disease (e.g., coronary artery disease, stroke, arrhythmias, congestive heart failure, uncontrolled hypertension) ( 4 ) During or within 14 days following the administration of monoamine oxidase inhibitors ( 4 ) Hyperthyroidism ( 4 ) Glaucoma ( 4 ) Agitated states ( 4 ) History of drug abuse ( 4 ) Pregnancy ( 4 , 8.1 ) Nursing ( 4 , 8.3 ) Known hypersensitivity, or idiosyncrasy to the sympathomimetic amines ( 4 )
Monoamine oxidase inhibitors: Risk of hypertensive crisis. ( 4 , 7.1 ) Alcohol: Consider potential interaction ( 7.2 ) Insulin and oral hypoglycemics: Requirements may be altered. ( 7.3 ) Adrenergic neuron blocking drugs: Hypotensive effect may be decreased by phentermine. ( 7.4 ) 7.1 Monoamine Oxidase Inhibitors Use of phentermine is contraindicated during or within 14 days following the administration of monoamine oxidase inhibitors because of the risk of hypertensive crisis. 7.2 Alcohol Concomitant use of alcohol with phentermine may result in an adverse drug reaction. 7.3 Insulin and Oral Hypoglycemic Medications Requirements may be altered [ see Warnings and Precautions ( 5.9 ) ]. 7.4 Adrenergic Neuron Blocking Drugs Phentermine may decrease the hypotensive effect of adrenergic neuron blocking drugs.
| 3 | Not yet rated | Prescription | Capsule | Generic | $3 | View → |
| 4 | Not yet rated | Prescription | Tablet | Generic | $3 | View → |