Endocrine Abstracts

Introduction: More than 50 years after its introducing in 1957 (1996 in USA), metformin is used today in more than 90 countries. It is the most efficient, safe and costless anti-hyperglycemic agent in the treatment of type 2 diabetes mellitus. Its principal risk remains metformin-associated lactic acidosis (MALA), subject of controversies as reported in a recent Cochrane database review in 2010.

Patients and methods: We present personal series of all cases of MALA diagnosed in an 8 year-period in an Emergency department admitting 16 000 patients yearly.

Serum lactic acid over than 5 mmol/l at admission (normal value <2 mmol/l) in a context of metabolic acidosis is the key of the diagnosis.

Results: Four cases of MALA are diagnosed in this 8 year-period. The incidence is three for 100 000 patients admitted in emergency.

The indication of the metformin was not relevant in 1 case (mitochondrial disease) and subject of discussion in two others (with chronic alcoholism in on case and chronic use of anti-inflammatory drugs in the other). The case 4 treated with 3000 mg of metformin, presents also a mild asthma.

The clinical presentation is misleading in the four cases. The evolution was favorable in 50% of the cases, fatal in two cases (severe impaired renal function, hepatic insufficiency).

Discussions and conclusions: MALA incidence is probably underestimated. The frequency of co-morbidity makes its diagnosis difficult. Checking serum lactic acid for all diabetic patients treated with metformin when admitted for any acute problem in emergency is the main ‘take home message’ of this report.

Diagnosed and treated without delay, the evolution of MALA can be quickly favorable.

In UKPDS, Metformin given not more than 2550 mg daily has shown to reduce total mortality but no clinical evidence for the superiority of higher doses in studies.

We suggest, in addition to the strict respect of contraindications, the integration of the benefit-risk balance when prescribing higher doses.

Finally, the expertise of Diabetologists in Emergency rooms could improve the quality of care for diabetic patients. Helpful in the management and prevention of complications, it is enhancing educational messages of safety for patients and physicians.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.