How long can insulin therapy be avoided in the patient with type 2 diabetes mellitus by use of a combination of metformin and a sulfonylurea?
OBJECTIVE
To assess the effective longevity of combination double oral therapy before insulin or triple oral therapy is needed in patients with type 2 diabetes mellitus.


METHODS
We retrospectively reviewed the outcomes of our first 100 patients with type 2 diabetes who were successfully transferred from twice-daily mixed NPH and regular insulin to a combination of metformin and a sulfonylurea.


RESULTS
Of the 100 study patients, 40 had well-controlled plasma glucose (glycosylated hemoglobin levels <8.0%) with use of metformin and a sulfonylurea. Good glycemic control was achieved with triple oral therapy (a sulfonylurea, metformin, and a thiazolidinedione) in 14 patients and with a sulfonylurea, metformin, and evening-administered mixed NPH and regular insulin in 7. In addition, plasma glucose was effectively controlled with twice-daily mixed NPH and regular insulin in conjunction with metformin or a thiazolidinedione (or both) in 22 patients and with twice-daily mixed NPH and regular insulin alone in 17. The mean time (+/- standard error) from primary failure of sulfonylurea monotherapy to the time when a third hypoglycemic agent was needed was 7.9 +/- 1.1 years (95% confidence interval, 5.7 to 10.1).


CONCLUSIONS
When oral monotherapy fails (that is, glycosylated hemoglobin values exceed 8.0%) in patients with type 2 diabetes, combination therapy with a sulfonylurea and metformin is potentially effective in maintaining glycemic control and avoiding the addition of insulin or a thiazolidinedione for a mean duration of 7.9 years.
Department of Medicine, University of Alabama at Birmingham, School of Medicine, Birmingham, Alabama, USA.
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Bell
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Ovalle
D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D004359:Drug Therapy, Combination; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000627:therapeutic use; D008687:Metformin / Q000627:therapeutic use*; D019233:Retreatment; D012189:Retrospective Studies; D013453:Sulfonylurea Compounds / Q000627:therapeutic use*; D013844:Thiazoles / Q000627:therapeutic use; D045162:Thiazolidinediones; D013997:Time Factors
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin; D013453:Sulfonylurea Compounds; D013844:Thiazoles; D045162:Thiazolidinediones; C089946:2,4-thiazolidinedione