Anorexigens and pulmonary hypertension in the United States - Results fromthe surveillance of North American pulmonary hypertension

Background: The use of appetite suppressants in Europe has been associated with the development of primary pulmonary hypertension (PPH), Recently, fen fluramine appetite suppressants became widely used in the United States but were withdrawn in September 1997 because of concerns over adverse effects. Materials and Methods: We conducted a prospective surveillance study on pat ients diagnosed with pulmonary hypertension at 12 large referral centers il l North America, Data collected on patients seen from September 1, 1996, to December 31, 1997, included the cause of the pulmonary hypertension and it s severity. Patients with no identifiable cause of pulmonary hyper tension were classed as PPH, A history of drug exposure also was taken with special attention on the use of antidepressants, anorexigens, and amphetamines, Results: Five hundred seventy-nine patients were studied, 205 with PPH and 374 with pulmonary hypertension front other causes (secondary pulmonary hyp ertension [SPH]). The use of anorexigens was common in both groups. However , of the medications surveyed, only the fenfluramines had a significant pre ferential association with PPH as compared with SPH (adjusted odds ratio fo r use > 6 months, 7.5; 95% confidence interval, 1.7 to 32.4). The associati on was stronger with longer duration of use when compared to shorter durati on of use and was more pronounced in recent users than in remote users. An unexpectedly high (11.4%) number of patients with SPR had used anorexigens. Conclusion: The magnitude of the association with PPH, the increase of asso ciation with increasing duration of use, and the specificity for fenflurami nes are consistent with previous studies indicating that fenfluramines are causally related to PPH, The high prevalence of anorexigen use in patients with SPH also raises the possibility that these drugs precipitate pulmonary hypertension in patients with underlying conditions associated with SPH.