[Iatrogenic pulmonary artery hypertension].

Primary pulmonary arterial hypertension (PPH) is a rare disorder with a predilection for young subjects (most commonly of 20-40 years) and of the female sex. The prognosis is very poor because the average life expectancy is of the order of two to three years from the time of diagnosis. Since the epidemic of PPH observed in Switzerland, Austria and Germany in the years between 1968 and 1970, following the arrival of a derivative of amphetamine, Aminorex, it was realised that certain medications, notably appetite suppressants, might play an initiating role. More recently, fenfluramine and dexfenfluramine have been incriminated: in a significant statistic of A-beclere's team, around 20% of cases of PPH were observed in patients who had taken fenfluramine or dexfenfluranime for more than three months. A very recent case-control study has shown that any use of anorexic drugs (mainly fenfluramine derivatives) was associated with an increased risk of PPH (odds ratio: 6/1), and particularly when the duration of treatment exceeds 3 months. Outside the group of appetite suppressants few medications are capable of favouring the development of PPH, the cases are sporadic and the relationship between cause and effect is hardly established.