Phentermine Hydrochloride
FDA Drug Information • Also known as: Lomaira, Phentermine, Phentermine Hcl, Phentermine Hydrochloride
- Brand Names
- Lomaira, Phentermine, Phentermine Hcl, Phentermine Hydrochloride
- Route
- ORAL
- Dosage Form
- TABLET
- Product Type
- HUMAN PRESCRIPTION DRUG
Description
11 DESCRIPTION Phentermine hydrochloride is a sympathomimetic amine anorectic. Its chemical name is α,α,-dimethylphenethylamine hydrochloride. The structural formula is as follows: Phentermine hydrochloride is a white, odorless, hygroscopic, crystalline powder which is soluble in water and lower alcohols, slightly soluble in chloroform and insoluble in ether. Phentermine hydrochloride is available as a capsule and tablet containing 37.5 mg of phentermine hydrochloride (equivalent to 30 mg of phentermine base). Phentermine hydrochloride capsules, USP contain the inactive ingredients: corn starch, D&C Red #33, FD&C Blue #1, gelatin, lactose monohydrate, magnesium stearate and titanium dioxide. Phentermine hydrochloride tablets, USP contain the inactive ingredients: corn starch, colloidal silicon dioxide, FD&C blue #1, lactose monohydrate, magnesium stearate, microcrystalline cellulose, stearic acid, and sucrose. chemical structure
What Is Phentermine Hydrochloride Used For?
1 INDICATIONS AND USAGE Phentermine hydrochloride, USP 37.5 mg is indicated as short-term (a few weeks) adjunct in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous obesity for patients with an initial body mass index greater than or equal to 30 kg/m 2 , or greater than or equal to 27 kg/m 2 in the presence of other risk factors (e.g., controlled hypertension, diabetes, hyperlipidemia). Below is a chart of Body Mass Index (BMI) based on various heights and weights. BMI is calculated by taking the patient’s weight, in kilograms (kg), divided by the patient’s height, in meters (m), squared. Metric conversions are as follows: pounds ÷ 2.2 = kg; inches x 0.0254 = meters. The limited usefulness of agents of this class, including Phentermine hydrochloride, [see CLINICAL PHARMACOLOGY ( 12.1 , 12.2 ) ] should be measured against possible risk factors inherent in their use such as those described below. Phentermine Hydrochloride is a sympathomimetic amine anorectic indicated as a short-term adjunct (a few weeks) in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous obesity for patients with an initial body mass index greater than or equal to 30 kg/m 2 , or greater than or equal to 27 kg/m 2 in the presence of other risk factors (e.g., controlled hypertension, diabetes, hyperlipidemia). ( 1 ) The limited usefulness of agents of this class, including Phentermine hydrochloride, should be measured against possible risk factors inherent in their use. ( 1 ) BMI Index
Dosage and Administration
2 DOSAGE AND ADMINISTRATION 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/1.73 m 2 ) ( 2.2 ) 2.1 Exogenous Obesity Dosage should be individualized to obtain an adequate response with the lowest effective dose. The usual adult dose is one tablet (37.5 mg) or one capsule (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 impairments (eGFR 15 to 29 mL/min/1.73 m 2 ). Avoid use of phentermine hydrochloride in patients with eGFR less than 15 mL/min/1.73 m 2 or end-stage renal disease requiring dialysis [see Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12.3 ) ].
Side Effects (Adverse Reactions)
6 ADVERSE REACTIONS The following adverse reactions are described, or described in greater detail, in other section: 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. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact KVK-TECH, Inc., at 1-800-862-3895 or [email protected]; or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Drug Interactions
7 DRUG INTERACTIONS 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.
Contraindications
4 CONTRAINDICATIONS 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 )
Overdosage
10 OVERDOSAGE The least amount feasible should be prescribed or dispensed at one time in order to minimize the possibility of overdosage. 10.1 Acute Overdosage Manifestations of acute overdosage include restlessness, tremor, hyperreflexia, rapid respiration, confusion, assaultiveness, hallucinations, and panic states. Fatigue and depression usually follow the central stimulation. Cardiovascular effects include tachycardia, arrhythmia, hypertension or hypotension, and circulatory collapse. Gastrointestinal symptoms include nausea, vomiting, diarrhea and abdominal cramps. Overdosage of pharmacologically similar compounds has resulted in fatal poisoning usually terminates in convulsions and coma. Management of acute phentermine hydrochloride intoxication is largely symptomatic and includes lavage and sedation with a barbiturate. Experience with hemodialysis or peritoneal dialysis is inadequate to permit recommendations in this regard. Acidification of the urine increases phentermine excretion. Intravenous phentolamine (Regitine ® , CIBA) has been suggested on pharmacologic grounds for possible acute, severe hypertension, if this complicates overdosage. 10.2 Chronic Intoxication Manifestations of chronic intoxication with anorectic drugs include severe dermatoses, marked insomnia, irritability, hyperactivity and personality changes. The most severe manifestation of chronic intoxications is psychosis, often clinically indistinguishable from schizophrenia. See Drug Abuse and Dependence ( 9.3 ) .
How Supplied
16 HOW SUPPLIED/STORAGE AND HANDLING Product: 50090-1679 NDC: 50090-1679-0 30 TABLET in a BOTTLE NDC: 50090-1679-1 45 TABLET in a BOTTLE NDC: 50090-1679-2 60 TABLET in a BOTTLE NDC: 50090-1679-3 28 TABLET in a BOTTLE NDC: 50090-1679-4 7 TABLET in a BOTTLE NDC: 50090-1679-5 14 TABLET in a BOTTLE NDC: 50090-1679-6 90 TABLET in a BOTTLE
About This Information
This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.
What are side effects?
Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.
What are drug interactions?
Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.