Medicine Regulatory Authorities first became aware of the presence of the nitrosamine impurity Nnitrosodimethylamine NDMA in products containing valsartan in July 2018 Valsartan is an Angiotensin II Receptor Blocker ARB and belongs to a family of analogue compounds commonly referred to as the sartans Further nitrosamine impurities were subsequently detected in other medicines belonging to the sartan family including N nitrosodiethylamine NDEA N nitrosodiisopropylamine NDIPA N nitrosoethylisopropylamine NEIPA and N nitroso N methyl 4 aminobutyric acid NMBA