VA Class:GA751
Phendimetrazine tartrate is an amphetamine congener that is used as an anorexigenic agent.
Phendimetrazine is used as an adjunct to caloric restriction in the short-term treatment (a few weeks) of exogenous obesity. The anorexigenic effect of sympathomimetic compounds used in the treatment of obesity is temporary, seldom lasting more than a few weeks and tolerance may occur. To help bring about and maintain loss of weight, the patient must be taught to curtail overeating and to consume a suitable diet. As with other anorexigenic agents, prolonged administration of phendimetrazine is not indicated.
Phendimetrazine tartrate is administered orally.
The usual adult dosage of phendimetrazine tartrate is 35 mg 2 or 3 times daily, given one hour before meals. Dosage should be adjusted to individual response and tolerance and may range from 17.5 mg twice daily to a maximum of 70 mg 3 times daily. The usual adult dosage of the extended-release capsules is 105 mg once daily in the morning.
Adverse nervous system effects of phendimetrazine may include overstimulation, restlessness, agitation, sweating, dizziness, insomnia, euphoria, dysphoria, tremor, and headache. Rarely, psychotic episodes may occur in patients receiving recommended dosages.
Adverse GI effects of phendimetrazine may include dryness of the mouth, unpleasant taste, diarrhea, nausea, stomach pain, and constipation.
Cardiovascular and Pulmonary Effects 
Abnormal heart valve findings and/or primary pulmonary hypertension have been reported in some patients receiving phendimetrazine tartrate.100 One manufacturer of phendimetrazine tartrate (Plegine®) states that patients who experienced valvulopathy and/or primary pulmonary hypertension also have received at least one other anorexigenic agent.100 Because of severe and unusual mitral, aortic, tricuspid, and/or pulmonary valvular (usually multivalvular) and echocardiographic abnormalities (that sometimes occurred concomitantly with pulmonary hypertension, occasionally required open heart surgery, and rarely were fatal) reported in patients receiving fenfluramine (Pondimin®) or dexfenfluramine (Redux®), these drugs were withdrawn from the US market in September 1997.100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120 The adverse effects associated with these drugs were based on postmarketing reports from the Mayo Clinic and other health-care facilities about heart valve disease occurring in patients who usually were receiving combined therapy with fenfluramine and phentermine for the management of obesity.101,102,103,104,105,106,107,108,109,110,111,112,113 (See Cautions, in the Amphetamines General Statement 28:20.04.) Since the withdrawal of fenfluramine and dexfenfluramine from the US market, there have been reports that clinicians started prescribing phendimetrazine in combination with phentermine for the management of exogenous obesity in a limited number of patients.100 One manufacturer of phendimetrazine tartrate (Plegine®) states that the drug should be used only for short-term management (a few weeks) of exogenous obesity and should not be used in combination with other anorexigenic agents.100,120
Palpitation, tachycardia, and increased blood pressure may occur in patients receiving phendimetrazine.
Urticaria, blurred vision, urinary frequency, dysuria, impotence, and changes in libido may occur in patients receiving phendimetrazine.
Precautions and Contraindications
Patients should be warned that phendimetrazine may impair their ability to perform activities requiring mental alertness or physical coordination (e.g., operating machinery, driving a motor vehicle). Phendimetrazine should be used with caution in patients with mild hypertension, and blood pressure should be monitored closely.
Abnormal heart valve findings and primary pulmonary hypertension have been reported in some patients receiving phendimetrazine tartrate.100,120 One manufacturer of phendimetrazine tartrate (Plegine®) states that patients who experienced valvulopathy and/or primary pulmonary hypertension also have received at least one other anorexigenic agent.100 Primary pulmonary hypertension is a rare, frequently fatal pulmonary disease that has been reported with increased frequency in patients receiving anorexigenic agents.100,120 (For further information about amphetamine-associated valvulopathy and primary pulmonary hypertension, see Cautions, in the Amphetamines General Statement 28:20.04.) One manufacturer of phendimetrazine tartrate (Plegine®) states that the drug should be used only for short-term management (a few weeks) of exogenous obesity and should not be used in combination with other anorexigenic agents.100,120
Habituation or addiction has been reported with phenmetrazine and the possibility of its occurrence should be considered with phendimetrazine.
Phendimetrazine is contraindicated in patients with hyperthyroidism, moderate to severe hypertension, advanced arteriosclerosis, symptomatic cardiovascular disease, glaucoma, or known hypersensitivity or idiosyncrasy to sympathomimetic amines. The drug also is contraindicated in patients in agitated states or those who are highly nervous, have a history of drug abuse, or are receiving CNS stimulants. Phendimetrazine is contraindicated during or within 14 days of administration of monoamine oxidase (MAO) inhibitors since hypertensive crisis could result.
Phendimetrazine should not be used in children younger than 12 years of age.
Safe use of phendimetrazine during pregnancy has not been established. During pregnancy it is questionable whether potential benefits from anorexigenic agents outweigh potential risks and this condition should probably be considered a contraindication to their use, especially during the first trimester. Phendimetrazine should not be used in women who may become pregnant unless, in the opinion of the physician, the potential benefits outweigh the possible risks.
Safe use of phendimetrazine during lactation has not been established.
Insulin requirements in patients with diabetes mellitus may be decreased in association with the use of phendimetrazine and the concomitant dietary regimen and weight loss; therefore, phendimetrazine should be used with caution in patients with diabetes mellitus.
Like amphetamines, phendimetrazine may decrease the hypotensive effect of guanethidine.
In experimental animals and in clinical studies in humans, phendimetrazine apparently produces an anorexigenic effect and loss of weight. As with other amphetamine derivatives, no primary effect on appetite has been demonstrated with phendimetrazine and it is probable that its anorexigenic effect is secondary to CNS stimulation. Although animal studies indicate that the cardiovascular and respiratory effects of phendimetrazine are not as pronounced as those of phenmetrazine, the clinical importance of these findings is questionable.
Phendimetrazine is readily absorbed from the GI tract and effects persist for about 4 hours after oral administration.
Phendimetrazine tartrate is an amphetamine congener that is used as an anorexigenic agent. Phendimetrazine tartrate occurs as a bitter, white, odorless, crystalline powder and is freely soluble in water and sparingly soluble in warm alcohol.
Phendimetrazine tartrate capsules, extended-release capsules, and tablets should be stored in well-closed containers at a temperature less than 40°C, preferably at 15-30°C.
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
Phendimetrazine tartrate is subject to control under the Federal Controlled Substances Act of 1970 as a schedule III (C-III) drug.
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Oral | Capsules, extended-release | 105 mg* | Adipost® (C-III) | |
Bontril® Slow Release (C-III) | ||||
Melfiat®-105 Unicelles® (C-III) | ||||
Phendimetrazine Tartrate Capsules LA (C-III) | ||||
X-Trozine® LA (C-III) | ||||
Tablets | 35 mg* | Bontril® PDM (C-III; scored) | Valeant |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
AHFS® Drug Information. © Copyright, 1959-2024, Selected Revisions November 20, 2012. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, MD 20814.
Only references cited for selected revisions after 1984 are available electronically.
100. Wyeth-Ayerst. Dear health care professional letter regarding valvular irregularities and primary pulmonary hypertension associated with the use of Plegine®. Philadelphia, PA Wyeth-Ayerst; 1998 Jun 15.
101. Deitch MW. Dear health care provider letter: Pondimin and Redux to be voluntarily withdrawn. Philadelphia, PA: Wyeth-Ayerst; 1997 Sep 15.
102. Wyeth-Ayerst. Pondimin and Redux to be voluntarily withdrawn. Philadelphia, PA: 1997 Sep 15. Press release.
103. Lumpkin MM. FDA public health advisory: reports of valvular heart disease in patients receiving concomitant fenfluramine and phentermine. Rockville, MD: Food and Drug Administration; 1997 Jul 8.
104. Connolly HM, Crary JL, McGoon MD et al. Valvular heart disease associated with fenfluramine-phentermine. N Engl J Med . 1997; 337:581-8. [PubMed 9271479]
105. Anon. FDA steps up campaign to discourage off-label “fen/phen” use with public health advisory; agency coordinates message with NEJM, Mayo clinic. FDC Rep . 1997; (Jul 14):4-5.
106. Anon. Knoll Meridia studies continue after Redux, Pondimin withdrawal: lawsuits call for Wyeth to fund medical monitoring of patients exposed to drugs. FDC Rep . 1997; (Sep 22):5.
107. US Food and Drug Administration. Questions and answers about Phen/fen and valvular heart disease. Rockville, MD; 1997 July 8.
108. Plutowski S (Mayo Foundation for Medical Education and Research). Valvular heart disease associated with commonly prescribed diet pills. Rochester, MN; 1997 Jul 8. Press release from website. [Web]
109. Mayo Foundation for Medical Education and Research. Information for physicians regarding pharmacologic therapy for obesity. Rochester, MN; 1997 Jul 7. Press release from website. [Web]
110. Mayo Foundation for Medical Education and Research. Heart valve disease and fen-phen: NEJM waives embargo for Mayo Clinic announcement. Rochester, MN; 1997 Jul 8. Press release from website. [Web]
111. Anon. FDA fenfluramine/Redux epidemiological analysis of HMO records supports findings of valvulopathy in asymptomatic patients reported from five surveys. FDC Rep . 1997; (Sep 15):3-5.
112. Connolly HM, Crary JL, McGoon MD et al. for the Mayo Foundation for Medical Education and Research. Valvular heart disease associated with fenfluramine-phentermine. Rochester, MN; 1997 Jul 8.
113. Mayo Foundation for Medical Education and Research. Information and recommendations for people taking fenfluramine and phentermine. Rochester, MN; 1997 Jul 8.
114. Graham DJ, Green L. Further cases of valvular heart disease associated with fenfluramine-phentermine. N Engl J Med . 1997; 337:635. [PubMed 9280830]
115. Centers for Disease Control and Prevention. Cardiac valvulopathy associated with exposure to fenfluramine or dexfenfluramine: U.S. Department of Health and Human Services interim public health recommendations, November 1997. MMWR Morb Mortal Wkly Rep . 1997; 46:1061-6. [PubMed 9385873]
116. Medeva. Ionamin® (C-IV) (phentermine resin capsules) prescribing information. Rochester, NY; 1997 Oct.
117. Coyne CT. Dear health care professional letter regarding labeling changes of Ionamin (phentermine resin capsules). Rochester, NY: Medeva; 1997 Aug 8.
118. Coyne CT. Dear doctor or health care professional letter regarding appropriate use of Ionamin (phentermine resin capsules). Rochester, NY: Medeva; 1997 Sep 18.
119. SoRelle R. Fen-phen and risk of valvular disease. Circulation . 1997; 96:1705-6. [PubMed 9323046]
120. Wyeth-Ayerst. Plegine® (phendimetrazine tartrate tablets) prescribing information. In: Physicians' desk reference. 52nd ed. Montvale, NJ: Medical Economics Company Inc; 1998(Suppl A):A304.