A study of the possible interaction of indoprofen with hypoglycemic sulfonylureas in diabetic patients

Phenylbutazone was shown to impair tolbutamide metabolism with resulting potentiation of its hypoglycemic effect and increased danger of hypoglycemia. As indoprofen is widely used for treating rheumatic conditions, and in particular osteoarthritis, the possibility that it may increase the effect of sulfonylureas on blood glucose levels has been investigated. Clinical studies have been carried out in 24 patients with osteoarthritis. All of them had maturity-onset diabetes mellitus and were on sulfonylurea drugs (tolbutamide or glipizide). The trials were double-blind and were carried out according to two different experimental designs. Twelve patients were treated with 600 mg/daily of indoprofen for five days and placebo for an equivalent period of time according to a cross-over scheme. Another group of patients was treated with indoprofen for eight days preceded and followed by a four-day placebo treatment. In both studies concomitant treatment with the hypoglycemic drug was maintained with a fixed dosage. No important differences were found between blood glucose levels when the periods of treatment with indoprofen and placebo were compared. Consequently, it is unlikely that indoprofen treatment at the doses employed may interfere at the clinical level with the effect of tolbutamide or glipizide on glucose metabolism.