Dietary pulmonary hypertension.

In 1967 Kay et al postulated that some cases of unexplained pulmonary hypertension might be due to the ingestion of drugs or other toxic substances.' This concept, later termed dietary pulmonary hypertension,23 was advanced following the observation that the oral administration to rats of the pyrrolizidine alkaloid monocrotaline produced severe pulmonary hypertension.' There are no reports of pyrrolizidine alkaloids causing pulmonary hypertension in human subjects, but there have been two epidemics ofpulmonary hypertension caused by the ingestion of other substances, and several reports of pulmonary hypertension associated with the administration of drugs (table). The two epidemics of pulmonary hypertension were related to the ingestion of an appetite suppressing drug aminorex,4 and to the ingestion of denatured rapeseed oil.5 Pulmonary hypertension has also been reported in two obese patients taking phenformin.6 Severe pulmonary hypertension associated withhaemolytic anaemia and renal failure occurred in a 46 year old man with carcinoma of the colon who was treated with mitomycin.7 Pulmonary veno-occlusive disease has been described in patients receiving chemotherapy with BCNU5 and bleomycin alone,9 or in combination with mitomycin and cisplatin,'° or mitomycin, cisplatin and vinblastine."1 The effects of pyrrolizidine alkaloids, anorexigens, L-tryptophan, and toxic oil on the pulmonary vasculature are considered in the following review.