Remedial Actions Following High Blood Pressure Drug Recall
Ministry of HealthSpeakers
Summary
This question concerns the recall of three brands of losartan medication, with Ms Joan Pereira asking what measures ensure drugs are tested and cleared before being released into the market. Minister Gan Kim Yong replied that the Health Sciences Authority (HSA) conducts pre-market evaluations and post-market surveillance to ensure medicines meet international standards of quality and safety. He explained that while manufacturers test for known impurities, nitrosamines were not previously part of global testing parameters as they were not expected to be generated during production. HSA now requires all companies supplying angiotensin receptor blockers to test and ensure future batches contain no unacceptable nitrosamine levels before being sold in Singapore. Finally, the Minister highlighted that HSA is collaborating with international regulatory agencies to verify the causes of contamination and develop measures to eliminate these impurities.
Transcript
15 Ms Joan Pereira asked the Minister for Health regarding the three brands of a high blood pressure drug which are being recalled, what is being done to ensure that all medication is tested and cleared before being released into the market.
Mr Gan Kim Yong: On 28 March 2019, the Health Sciences Authority (HSA) recalled three brands of medicines which belong to the angiotensin receptor blocker (ARB) class of blood pressure medication and contain the ingredient losartan. All three medicines were manufactured by Hetero Labs Limited. Following the recall of several losartan medicines in US due to the presence of a nitrosamine impurity, N-nitroso-N-methyl-4-aminobutyric acid (NMBA), HSA tested the suspected losartan medicines and they were found to contain trace amounts of NMBA which are above the acceptable limit1.
Under HSA's drug regulatory regime, stringent standards are set on the quality and safety of medicines sold in Singapore. Before being approved for sale, the medicines are evaluated to ensure that they meet the required international standards of quality, safety and efficacy. After approval, HSA conducts post-market surveillance, which includes monitoring of global developments and risk-based product sampling and testing for compliance to quality and safety specifications. Products found to be deficient in quality will be withdrawn from the market. Manufacturers are also required to test all batches of medicines, including the levels of specific impurities, to ensure that they comply with stipulated standards.
The routine tests required of the manufacturers are based on known impurities that may be generated during the manufacturing process, as it is not practical to exhaustively test for all types of impurities. In the case of the recalled losartan medicines, testing for nitrosamines like NMBA was not previously part of the testing parameters of ARB medicines as NMBA was not expected to be generated in the manufacturing process. This approach is similar to that adopted in other countries including the US, Canada and the European Union.
HSA now requires companies supplying ARBs to ensure that future batches of their medicines are tested and do not have unacceptable levels of nitrosamine impurities before supply to Singapore. HSA has also been working with suppliers and international regulatory agencies to verify the cause of contamination and to formulate measures to eliminate the nitrosamines in the medium to longer term. HSA will continue to monitor the quality and safety of these medicines to safeguard public health.