Contra-indications to metformin therapy are largely disregarded

Diabet Med. 1999 Aug;16(8):692-6. doi: 10.1046/j.1464-5491.1999.00115.x.


Aims: To investigate the current metformin treatment practice and in particular to examine the consideration given to its contraindications.

Methods: A cross-sectional analysis of 308 consecutive Type 2 diabetic patients (mean age 66+/-11.3 years) previously treated with metformin on an outpatient basis and admitted to a German general hospital during the period from 1 January 1995 to 31 May 1998 because of acute disease or in order to optimize their diabetes management. All patients underwent a basic investigation comprising a documentation of their medical history, a physical examination, an electrocardiogram, and an extensive laboratory profile; 34% also had acute coronary angiography.

Results: On admission to hospital, 73% of the patients were found to have contra-indications, risk factors, or intercurrent illnesses necessitating discontinuation of metformin; 51% of these patients had several of these conditions. As major contra-indications to metformin, renal impairment was present in 19% of all patients, heart failure in 25%, respiratory insufficiency in 6.5%, and hepatic impairment in 1.3%. The risk factors to metformin included advanced coronary heart disease in 51%, atrial fibrillation in 9.8%, chronic alcohol abuse in 3.3%, advanced peripheral vascular disease in 2%, and pregnancy in 0.7%. As intercurrent illnesses, cerebral ischaemia occurred in 9.8% under metformin treatment and malignancies were diagnosed in 6.5%. The patients with contra-indications or requiring caution to metformin were significantly older and had previously been treated with more cardiovascular medication than those without such reservations (P<0.001).

Conclusions: Despite the considerable risk of lactic acidosis in the majority of patients, no cases were observed.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Contraindications
  • Coronary Disease / epidemiology
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Diabetes Mellitus, Type 2 / physiopathology
  • Diabetic Angiopathies / epidemiology
  • Diabetic Neuropathies / epidemiology
  • Female
  • Germany
  • Heart Diseases / epidemiology
  • Hospitalization / statistics & numerical data*
  • Hospitals, General / statistics & numerical data
  • Humans
  • Hypoglycemic Agents*
  • Male
  • Metformin*
  • Pregnancy
  • Pregnancy in Diabetics / epidemiology
  • Respiratory Insufficiency / epidemiology
  • Risk Factors


  • Hypoglycemic Agents
  • Metformin