Dear Doctor or Health Care Professional:

The recent actions taken by Wyeth-Ayerst to withdraw their weight loss medications, Pondimin (fenfluramine hydrochloride) Tablets C-IV and Redux (dexfenfluramine hydrochloride) Capsules C-IV from the market have raised numerous questions and concerns about the status of other medications indicated in the treatment of exogenous obesity. Medeva Pharmaceuticals, Inc. would like to provide the medical community with important information about our product, IONAMIN (phentermine resin) Capsules C-IV.

This voluntary market withdrawal decision does NOT affect the availability of IONAMIN Capsules.

The decision to withdraw Pondimin and Redux was based on emerging information regarding significant adverse effects associated with these products. This information concerned abnormal heart valve findings which were determined to present an unacceptable risk to patients. The cases of valvular heart disease have reportedly involved patients taking fenfluramine in combination with phentermine; fenfluramine alone; dexfenfluramine alone; or dexfenfluramine in combination with phentermine. There have been no reported cases to date of this valvular condition occurring with the use of phentermine alone.

Primary pulmonary hypertension (PPH) is another significant adverse effect which has been reported to occur with increased frequency in patient using certain appetite suppressants (mainly fenfluramine or dexfenfluramine)^{1. Medeva is aware of only a few isolated case reports of PPH possibly associated with phentermine monotherapy over the last 38 years. Although present data do not support an association between PPH and phentermine monotherapy, the possibility cannot be ruled out.}

For patients with a history of fenfluramine or dexfenfluramine use, alone or in combination with phentermine, a thorough cardiac evaluation may be appropriate prior to embarking on a new therapeutic regimen for the treatment of obesity. The safety and efficacy of IONAMIN Capsules in patients with existing valvular dysfunction and/or heart murmur, in whom the influence of increased sympathomimetic activity may be undesirable, have not been established, and its use in such patients cannot be recommended.

IONAMIN (phentermine resin) Capsules C-IV are indicated in the management of exogenous obesity as a short-term (a few weeks) adjunct in a regimen of weight reduction based on caloric restriction. In addition to dietary adjustments, comprehensive weight loss programs also include behavioral modifications and increased physical activity, at a sufficient level to produce health benefits toward the improvement of obesity-related medical conditions.

IONAMIN Capsules are indicated as monotherapy only. There are no data to support the safety and/or efficacy of combination therapy with phentermine and any other drug products for the treatment of obesity, including serotonin reuptake inhibitors (e.g., fluoxetine, sertraline, paroxetine). The coadministration of these agents is not recommended.

At the present time, the long-term safety and efficacy of IONAMIN Capsules have not been systematically evaluated, and long-term use of IONAMIN Capsules is not recommended.

Use of pharmacotherapy for weight loss should not be instituted for cosmetic purposes, but rather, should be reserved for those individuals with a body mass index (BMI) of greater than or equal to 30 kg/m^{2, or for those with a BMI or greater than or equal to 27 kg/m2 in the presence of other risk factors (e.g., hypertension, diabetes, hyperlipidemia), in whom non-pharmacologic interventions have been unsuccessful.}

Further information regarding the withdrawal of Pondimin and Redux and valvular heart disease can be obtained from the FDA's Internet Website at http://www.fda.gov/cder/news/phen/fenphenqa2.htm. If you would like additional information about IONAMIN Capsules, the only phentermine resin product available, please contact Medeva's Medical Services Department at (800) 234-5535.

Sincerely,

Terrance C. Coyne, M.D.
Vice President, Medical Affairs

^{1 Abenhaim L, Moride Y, Brenot F, et al. Appetite suppressant drugs and the risk of primary pulmonary hypertension. International Primary Pulmonary Hypertension Study Group. N Engl J Med, 1966;335:609-616.}

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