Background Metformin is widely used against diabetes type II mellitus. Its most severe adverse effect is lactic acidosis. Although rare, the risk of its development can be increased by kidney failure (KF).

Purpose To report on pharmaceutical interventions (PIs) for preventing metformin-associated lactic acidosis (MALA) in diabetics admitted to hospital with KF and to evaluate their degree of acceptance.

Material and methods This prospective study (October 2013–March 2014) included all metformin-treated patients admitted. Creatinine clearance (CrCl) was estimated with the Cockcroft-Gault equation. PIs were: PI-1, stop-order for metformin when CrCl < 30 mL/min or CrCl = 30–45 mL/min associated with other MALA risk factors (MALA-RFs); PI-2, 50% reduction in maximum dose (2.550 mg/day) when CrCl = 30–45 mL/min with no other MALA-RF; PI-3, request for new renal function analysis when CrCl is unknown. MALA-RFs considered: kidney, liver, heart and respiratory failure, infection, alcoholism, surgery, iodine contrast. Variables recorded: sex, age, hospital department, daily dose, serum creatinine, CrCl, MALA-RFs, PI performed.

Results During the study period, 234 metformin-treated patients were admitted (61.5% males), most frequently to the Cardiology Department (33.3%); mean (standard deviation) age was 71.3 (12.4) yrs; mean dose was 1,552.8 (560.7) mg/day. CrCl < 30 mL/min was recorded in 5.6% of patients, CrCl = 30–45 mL/min in 14.1%, and CrCl was unknown in 1.7%. PIs were performed in 44 patients (52.3% females, 61.4% ≥80 yrs). MALA-RFs: heart failure (34.1%), infection (34.1%), liver failure (22.7%), respiratory failure (18.2%) and surgery (4.5%). PIs performed: 38 PI-1 (34.2% when CrCl <30 mL/min), 2 PI-2 and 4 PI-3. Acceptance was 64.8% overall, 66.7% for PI-1 (91.7% when CrCl < 30 mL/min) and 66.7% for PI-3. No PI-2s were accepted.

Conclusion A small proportion of these patients had KF. A large majority of these required PI, most frequently PI-1. The degree of satisfaction was high and was especially elevated for PI-1 when CrCl was <30 mL/min.

References and/or acknowledgements AEMPS

No conflict of interest.