Reactions 618 - 14 Sep 1996

Dexfenfluramine warning issued byWyeth-Ayerst

Wyeth-Ayerst has sent ‘Dear Doctor’ letters to 300000 US healthcare professionals regarding the increasedrisk of primary pulmonary hypertension associated withdexfenfluramine [‘Redux’], the Pink Sheet reports.

Current labelling for the appetite suppressant statesthat the estimated risk of primary pulmonaryhypertension is 18 cases per million patients per year inthose taking dexfenfluramine for > 3 months. Thislabelling was based on preliminary findings of theInternational Primary Pulmonary Hypertension Study(IPPHS).*

However, the final report of the IPPHS study**

estimates a risk approximately 2-fold higher than thatpreviously estimated. Nevertheless, Wyeth-Ayerstmaintains that the actual risk remains small.

The letter also reiterates that dexfenfluramine is onlyindicated for patients with a body mass index (BMI) of atleast 30 kg/m2, or a BMI of at least 27 kg/m2 in thepresence of other risk factors such as hypertension,diabetes mellitus or hyperlipidaemia.* See Reactions 570: 3–4, 30 Sep 1995; see Reactions 570 p3-4;800314679** See this issue, Incidence Studies, p4; see Reactions 618 p4;800458115

Wyeth-Ayerst Redux Dear Doctor letter warns of higher pulmonary hypertensionrisk; Merck circulates Proscar meta-analysis response to V-A study. FDC Reports -Pink Sheet - Prescription Pharmaceuticals and Biotechnology 58: 9-10, 26 Aug1996 800468334

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Reactions 14 Sep 1996 No. 6180114-9954/10/0618-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved