Incidence, factors related to presentation, course and mortality of metformin-associated lactic acidosis in the healthcare area of a tertiary hospital

Abstract

ObjectivesTo determine the incidence of metformin-induced lactic acidosis during the period January 2014 to March 2017 in Aragon Healthcare Area III. To analyze the associated clinical and analytical factors and mortality. ResultsA total of 31 cases (61.3% males). Incidence: 79.76 cases/100,000 patients-year; mean age 75.39±9.34 years; 23 of them with levels of serum metformin (21.91±15.52mcg/ml); milligrams/day of metformin ingested: 1790.32±499; 96.8% of cases in the context of acute kidney failure; 11 cases with a history of chronic kidney disease (35.5%); 12 required intensive care (38.7%); 13 required purification treatment (41.9%; 3 hemodiafiltration, 10 hemodialysis). There was a significant correlation between daily milligrams of metformin ingested and drug levels; levels of metformin; and peak creatinine, pH and lactate. Mortality was 25.8%. There were only significant differences between the deceased and survivors regarding the duration of stay and final creatinine. Multivariate logistic regression did not detect any study variables associated with mortality. ConclusionsThe incidence in our healthcare area is higher than in other series, with a 25.8% mortality rate. Virtually all cases were in the context of prerenal acute kidney failure. In 29% of cases, there was an overdose. Patients must be warned about the most common lactic acidosis-inducing situations, especially dehydration, if they continue taking the drug at such times.