Centrally acting antiobesity products

Phentermine Hydrochloride

Approved 23 Oct 2003OralTablet

The FDA lists this product in 60 strengths and forms.

Indications

Phentermine hydrochloride is indicated as a 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 ≥ 30 kg/m 2 , or ≥ 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 × 0.0254 = meters. BODY MASS INDEX (BMI), kg/m 2 The limited usefulness of agents of this class, including phentermine hydrochloride tablets, [ 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 ≥ 30 kg/m 2 , or ≥ 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 )

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 )

Indications

( 1 ) The limited usefulness of agents of this class, including phentermine hydrochloride, should be measured against possible risk factors inherent in their use. ( 1 )

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 )

Warnings and precautions

Coadministration with other drugs for weight loss is not recommended (safety and efficacy of combination not established). ( 5.1 )
Rare cases of primary pulmonary hypertension have been reported. Phentermine should be discontinued in case of new, unexplained symptoms of dyspnea, angina pectoris, syncope or lower extremity edema. ( 5.2 )
Rare cases of serious regurgitant cardiac valvular disease have been reported. ( 5.3 )
Tolerance to the anorectic effect usually develops within a few weeks. If this occurs, phentermine should be discontinued. The recommended dose should not be exceeded. ( 5.4 )
Phentermine may impair the ability of the patient to engage in potentially hazardous activities such as operating machinery or driving a motor vehicle. ( 5.5 )
Risk of abuse and dependence. The least amount feasible should be prescribed or dispensed at one time in order to minimize the possibility of overdosage. ( 5.6 )
Concomitant alcohol use may result in an adverse drug reaction. ( 5.7 )
Use caution in patients with even mild hypertension (risk of increase in blood pressure). ( 5.8 )
A reduction in dose of insulin or oral hypoglycemic medication may be required in some patients. ( 5.9 )

5.1Coadministration With Other Drug Products for Weight Loss

Phentermine hydrochloride tablets are indicated only as short-term (a few weeks) monotherapy for the management of exogenous obesity. The safety and efficacy of combination therapy with phentermine and any other drug products for weight loss including prescribed drugs, over-the-counter preparations, and herbal products, or serotonergic agents such as selective serotonin reuptake inhibitors (e.g., fluoxetine, sertraline, fluvoxamine, paroxetine), have not been established.

Therefore, coadministration of phentermine and these drug products is not recommended.

5.2Primary Pulmonary Hypertension Primary Pulmonary Hypertension

(PPH) – a rare, frequently fatal disease of the lungs has been reported to occur in patients receiving a combination of phentermine with fenfluramine or dexfenfluramine. The possibility of an association between PPH and the use of phentermine alone cannot be ruled out; there have been rare cases of PPH in patients who reportedly have taken phentermine alone. The initial symptom of PPH is usually dyspnea. Other initial symptoms may include angina pectoris, syncope or lower extremity edema.

Patients should be advised to report immediately any deterioration in exercise tolerance. Treatment should be discontinued in patients who develop new, unexplained symptoms of dyspnea, angina pectoris, syncope or lower extremity edema, and patients should be evaluated for the possible presence of pulmonary hypertension.

5.3Valvular Heart Disease

Serious regurgitant cardiac valvular disease, primarily affecting the mitral, aortic and/or tricuspid valves, has been reported in otherwise healthy persons who had taken a combination of phentermine with fenfluramine or dexfenfluramine for weight loss. The possible role of phentermine in the etiology of these valvulopathies has not been established and their course in individuals after the drugs are stopped is not known.

The possibility of an association between valvular heart disease and the use of phentermine alone cannot be ruled out; there have been rare cases of valvular heart disease in patients who reportedly have taken phentermine alone.

5.4Development of Tolerance, Discontinuation in Case of Tolerance

When tolerance to the anorectant effect develops, the recommended dose should not be exceeded in an attempt to increase the effect; rather, the drug should be discontinued.

5.5Effect on the Ability to Engage in Potentially Hazardous Tasks

Phentermine may impair the ability of the patient to engage in potentially hazardous activities such as operating machinery or driving a motor vehicle; the patient should therefore be cautioned accordingly.

5.6Risk of Abuse and Dependence

Phentermine is related chemically and pharmacologically to amphetamine (d- and d/l-amphetamine) and to other related stimulant drugs that have been extensively abused. The possibility of abuse of phentermine should be kept in mind when evaluating the desirability of including a drug as part of a weight reduction program. See Drug Abuse and Dependence (9) and Overdosage (10) . The least amount feasible should be prescribed or dispensed at one time in order to minimize the possibility of overdosage.

5.7Usage With Alcohol

Concomitant use of alcohol with phentermine may result in an adverse drug reaction.

5.8Use in Patients With Hypertension

Use caution in prescribing phentermine for patients with even mild hypertension (risk of increase in blood pressure).

5.9Use in Patients on Insulin or Oral Hypoglycemic Medications for Diabetes Mellitus

A reduction in insulin or oral hypoglycemic medications in patients with diabetes mellitus may be required.

Phentermine Hydrochloride

Indications

Contraindications

Two medicines in one question?

Phentermine Hydrochloride

Indications

Contraindications

Two medicines in one question?

Warnings and precautions

5.1Coadministration With Other Drug Products for Weight Loss

5.2Primary Pulmonary Hypertension Primary Pulmonary Hypertension

5.3Valvular Heart Disease

5.4Development of Tolerance, Discontinuation in Case of Tolerance

5.5Effect on the Ability to Engage in Potentially Hazardous Tasks

5.6Risk of Abuse and Dependence

5.7Usage With Alcohol

5.8Use in Patients With Hypertension

5.9Use in Patients on Insulin or Oral Hypoglycemic Medications for Diabetes Mellitus

Interactions

7.1Monoamine Oxidase Inhibitors Use

7.2Alcohol

7.3Insulin and Oral Hypoglycemic Medications

7.4Adrenergic Neuron Blocking Drugs

Pregnancy and breastfeeding

8.1Pregnancy Pregnancy Category X

Adverse reactions

Composition

Strengths and forms

Official product information

At a glance