N-nitrosodimethylamine (NDMA), a probable human carcinogen, was discovered decades ago, although elevated levels in several widely used drugs were detected only recently. Several medications that are now known to contain NDMA have remained available, whereas ranitidine has been completely withdrawn from the market. In the following paper, we discuss the overview of events that led to the withdrawal of ranitidine and compare evidence and subsequent regulatory response of other medications also containing NDMA.

(1) Pulmonary vein stenosis (PVS) can be a severe, progressive disease with lung involvement. We aimed to characterize findings by computed tomography (CT) and identify factors associated with death; (2) Veins and lung segments were classified into five locations: right upper, middle, and lower; and left upper and lower. Severity of vein stenosis (0-4 = no disease-atresia) and lung segments (0-3 = unaffected-severe) were scored. A PVS severity score (sum of all veins + 2 if bilateral disease; maximum = 22) and a total lung severity score (sum of all lung segments; maximum = 15) were reported; (3) Of 43 CT examinations (median age 21 months), 63% had bilateral disease. There was 30% mortality by 4 years after CT. Individual-vein PVS severity was associated with its corresponding lung segment severity (p < 0.001). By univariate analysis, PVS severity score > 11, lung cysts, and total lung severity score > 6 had higher hazard of death; and perihilar induration had lower hazard of death; (4) Multiple CT-derived variables of PVS severity and lung disease have prognostic significance. PVS severity correlates with lung disease severity.