Effects of cilostazol, a phosphodiesterase inhibitor, on urinary excretion of albumin and prostaglandins in non-insulin-dependent diabetic patients.

Microalbuminuria is characteristic in diabetic nephropathy and is thought to be influenced by renal hemodynamics, especially by the metabolism of prostaglandins (PGs) in glomruli. To reduce urinary albumin excretion in patients with non-insulin-dependent diabetes mellitus (NIDDM), we administered 100 mg of cilostazol, a phosphodiesterase inhibitor, daily for 3 months. The urinary albumin index (UAI: microgram albumin/mg creatinine) decreased significantly after 3 months of administering cilostazol. Urinary excretions of thromboxane B2 (TXB2), a stable metabolite of thromboxane A2, decreased significantly after treatment. However, it had no effects on urinary excretions of PGE2 and 6-keto PGF1 alpha (6KF), a stable metabolite of prostacyclin. The ratio 6KF/TXB2 has been known to reflect the renal metabolism of PGs. In this study, urinary 6KF/TXB2 ratio increased significantly in parallel with a significant reduction of UAI. Cilostazol had no adverse effects on the control of blood glucose and lipids. In conclusion, cilostazol has a beneficial effect on UAI in patients with NIDDM by reducing renal production of TXB2., which increases 6KF/TXB2 ratio.