Stephen J.LurieMD, PhD, Senior EditorIndividualAuthor
To the Editor: Dr Horlen and colleagues1 found that approximately 25% of prescriptions for
metformin were to patients with diabetic contraindications such as CHF or
renal failure. This finding must be interpreted with caution.
First, it is unclear whether patients with a contraindication have a
higher relative risk of fatal lactic acidosis than those without contraindications.
Although Horlen et al cite findings that 90% of patients with lactic acidosis
had contraindications to metformin therapy, this does not provide an estimate
of the relative risk of lactic acidosis across a population of patients with
or without contraindications.
Cayley, Jr WE. Inappropriate Prescription for Metformin. JAMA. 2002;288(6):694-695. doi:10.1001/jama.288.6.693