Cyclothiazide/triamterene + Pravastatin - Drug Interactions

Clinical evidence,mechanism, importance and management

A 63-year-old woman who had been taking cyclothiazide/triamterene and acebutolol for 4 years,developed polyuria and polydipsia within 3 weeks of starting to take pravastatin 20mg daily, which gradually worsened. After another 4 months she was hospitalised for hyperglycaemia,which was treated with insulin and later glibenclamide (glyburide). The cyclothiazide/triamterene and pravastatin were stopped and gradually diabetic symptoms began to abate. Five weeks after admission she was discharged without need for any antidiabetic treatment with diabetes fully resolved (See reference number 1). The detailed reasons for this reaction are not understood, but it would seem that pravastatin increased hyperglycaemic potential of thiazide diuretic to point where frank diabetes developed. This is an isolated case and there would seem to be little reason normally to avoid concurrent use of these drugs.

1. Jonville-Bera A-P,Zakian A, Bera FJ, Carré P, Autret E. Possible pravastatin and diuretics-induced diabetes mellitus. Ann Pharmacother (1994) 28, 964–5.