DRUG REACTIONS

Dexfenfluramine warning issued by Wyeth-Ayerst

Wyeth-Ayerst has sent 'Dear Doctor' letters to 300 000 US healthcare professionals regarding the increased risk of primary pulmonary hypertension associated with dexfenfluramine ['Redux'], the Pink Sheet reports.

Current labelling for the appetite suppressant states that the estimated risk of primary pulmonary hypertension is 18 cases per million patients per year in those taking dexfenfluramine for> 3 months. This labelling was based on preliminary findings of the International Primary Pulmonary Hypertension Study (IPPHS).

However, the final report of the IPPHS study* estimates a risk approximately 2-fold higher than that previously estimated. Nevertheless, Wyeth-Ayerst maintains that the actual risk remains small.

The letter also reiterates that dexfenfluramine is only indicated for patients with a body mass index (BMI) of at least 30 kglm2, or a BMI of at least 27 kglm2 in the presence of other risk factors such as hypertension, diabetes mellitus or hyperlipidaemia. * See Inphanna 1053: 21, 7 Sep 1996; lnJ458115 Wyeth·Ayerst Redux Dear Doctor letter warns of bigher puJmonary hypertension

risk; Merck circula!es Proscar mcta-anaJysis response to V·A study. FDC Reports - Pink Sheet - Prescription Pharmaceuticals and BiOleClmology S8: 9-10, 26 Aug 1996 _,>4

0156-270319611054-00021/$01.00° AdlelrMm8t1onll1 LIm"" 1_. All rlghte.--rwcl

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Inphanna-14 Sep 11196 No. 1054