Pharmacist review prevents evolving metformin-associated lactic acidosis

What is known There is controversy surrounding the risk of metformin and the development of lactic acidosis. There have been no reports of a pharmacist preventing a patient developing metformin-associated lactic acidosis. Objectives Our objective was to report on a pharmacist potentially preventing an evolving case of metformin-associated lactic acidosis (MALA). Case description A patient who had been having episodes of nausea and vomiting for a year was referred for a home medicines review (HMR) by his general practitioner. The pharmacist who conducted the HMR suspected that the patient's symptoms could have been due to metformin. It was recommended to measure the serum lactate level and suspend metformin. Our patient was found to have a high lactate level and was referred to the emergency department by his general practitioner. Recovery was prompt with symptomatic support and cessation of metformin. What is new This appears to be the first case reported in the literature of a pharmacist recognizing an evolving case of MALA. Conclusion Although the incidence of MALA is rare, health professionals should be aware of the initial symptoms of lactic acidosis, especially in elderly patients with risk factors, to prevent a fatal lactic acidosis event.