Context According to package inserts, metformin is contraindicated in diabetic
patients receiving drug treatment for heart failure therapy, and thiazolidinediones
are not recommended in diabetic patients with symptoms of advanced heart failure.
Little is known about patterns of use of these antihyperglycemic drugs in
diabetic patients with heart failure.
Objective To determine the proportions of patients hospitalized with heart failure
and concomitant diabetes treated with metformin or thiazolidinediones.
Design Serial cross-sectional measurements using data from retrospective medical
Setting Nongovernmental acute care hospitals in the United States.
Patients Two nationally representative samples of Medicare beneficiaries hospitalized
with the primary diagnosis of heart failure and concomitant diabetes between
April 1998 and March 1999 and between July 2000 and June 2001.
Main Outcome Measures The prescription of either metformin or a thiazolidinedione at hospital
Results In the 1998-1999 sample (n = 12 505), 7.1% of patients were discharged
with a prescription for metformin, 7.2% with a prescription for a thiazolidinedione,
and 13.5% with a prescription for either drug. In the 2000-2001 sample (n
= 13 158), metformin use increased to 11.2%, thiazolidinedione use to
16.1%, and use of either drug to 24.4% (P<.001
for all comparisons). Similar increases were seen among patients of all age
groups, all races, and both sexes.
Conclusions The use of metformin and thiazolidinediones is common and has increased
rapidly in Medicare beneficiaries with diabetes and heart failure in direct
contrast with explicit warnings against this practice by the Food and Drug
Administration. Further studies to establish the safety and effectiveness
of this practice are needed to ensure optimal care of patients with diabetes
and heart failure.