To study whether pentoxifylline has additive renoprotective effect in patients taking ARB

In patients with CKD and serum creatinine 1.3~6.0 md/gl, having taken losartan 100 mg/day for at least 3 months, with stable renal function, will be recruited to a randomized open-label trial. Patients taking pentoxifylline or not will be compared for their spot urinary proteinuria, estimated glomerular filtration, spot urine tumor necrosis factor-α/creatinine ratio, spot urine monocyte-chemoattractant protein-1/creatinine, and aldosterone concentration between groups in a 2-year study. Add-on pentoxifylline in control group in the same dose as in treat group will be performed to observe the renoprotective effect if any protective potential is demonstrated in the end of maintenance 12 months.

Inclusion Criteria:

• Chronic kidney disease with serum creatinine 1.3~6.0 mg/dl

Exclusion Criteria:

• History of allergy to pentoxifylline
• Females are nursing or pregnant
• Obstructive uropathy
• Unable to stop chronic immunosuppressive therapy, NSAID
• Congestive heart failure (New York Heart Association functional class III or IV)
• Unstable angina, myocardial infarction, coronary artery bypass graft surgery, percutaneous coronary intervention, within the past 6 months prior to signing the informed consent form
• Cerebral hemorrhage within the past 6 months prior to signing the informed consent form
• Retinal hemorrhage within the past 6 months prior to signing the informed consent form
• Known or suspected secondary hypertension (e.g., primary aldosteronism, renovascular hypertension, pheochromocytoma)
• Severe uncontrolled hypertension with SBP > 220 mmHg and/or DBP > 115 mmHg
• Hepatic dysfunction as defined by the following laboratory parameters: ALT or AST > 2 times the upper limit of the normal range
• Biliary obstructive disorders (e.g. cholestasis)
• Active malignancy