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    DEA Class; Rx

    Common Brand Names; Adipex P, Lomaira

    • CNS Stimulants, Anorexiants; 
    • Stimulants; 
    • Sympathomimetic

    Oral sympathomimetic amine pharmacologically similar to amphetamines
    Used for short-term (a few weeks) treatment of exogenous obesity in patients 17 years and older; use generally not recommended by guidelines due to lack of longer-term health benefits
    Not recommended for long-term use; there is abuse and addiction potential

    Indicated for the short-term (i.e., a few weeks) treatment of obesity as an adjunct to reduced-calorie diet and lifestyle modifications.

    Short-term (few weeks) adjunctive use as part of weight-reduction regimen based on exercise, behavioral modification, and caloric restriction in management of exogenous obesity for patients with initial body mass index (BMI) ≥30 kg/m² or ≥27 kg/m² in presence of other risk factors (eg, controlled hypertension, diabetes, hyperlipidemia)

    Known hypersensitivity or idiosyncratic reaction to sympathomimetic amines

    History of cardiovascular disease (coronary artery disease, uncontrolled hypertension, arrhythmias, stroke, congestive heart failure)


    Agitated states


    History of drug abuse

    Use of monoamine oxidase inhibitors (MAOIs) within preceding 14 days; concomitant administration of other CNS stimulants

    Pregnancy and breast feeding

    • Bad taste in mouth
    • Blurred vision
    • Changes in libido
    • Chills
    • Constipation
    • Diarrhea
    • Drug-induced GI disturbance
    • Dry mouth
    • Dysphoric mood
    • Dysuria
    • Excitement
    • Hair loss
    • Headache
    • Hypertension
    • Impotence
    • Insomnia
    • Myalgia
    • Nausea
    • Nervousness
    • Palpitations
    • Restlessness
    • Tachycardia
    • Tremor
    • Urticaria
    • Vomiting

    Primary pulmonary hypertension and valvular disease have been reported with therapy

    Avoid use of stimulants in patients with serious heart rhythm disturbances, cardiac abnormalities, cardiomyopathies, or other cardiac problems (see Contraindications)

    Caution in hypertension; risk of increase in blood pressure

    Patients with diabetes mellitus should use caution with antidiabetic agents like insulin or other hypoglycemic agents; dietary restrictions may lower requirements for antidiabetic therapy

    Drug has not been studied in renal impairment

    Use with caution in patients with seizure disorders or Tourette syndrome

    May impair ability to operate heavy machinery

    Concomitant administration with other weight-loss agents (eg, selective serotonin reuptake inhibitors [SSRIs], herbal preparations, other over-the-counter products) has not been studied

    Elderly are at high risk for myocardial infarction, hypertension, angina, or becoming dependent on phentermine with prolonged use

    Discontinue if weight loss has not occurred with 4 weeks of therapy

    Not approved for long-term use

    Discontinue if tolerance develops, and do not exceed recommended dosage to overcome tolerance

    Pregnancy category: X

    Lactation: Unknown if excreted in milk; contraindicated


    37.5 mg/day PO.


    37.5 mg/day PO.


    17 years: 37.5 mg/day PO.
    12 to 16 years: Safety and efficacy have not been established.


    Safety and efficacy have not been established.


    Safety and efficacy have not been established.


    Safety and efficacy have not been established.

    Phentermine hydrochloride

    capsule, HCl salt: Schedule IV

    • 15mg (generics)
    • 30mg (generics)
    • 37.5mg (Adipex P, generics)

    tablet, HCl salt: Schedule IV

    • 8mg (Lomaira)
    • 37.5mg (Adipex P, generics)