Effect of Pentoxifylline on GFR Decline in CKD: A Pilot, Double-Blind, Randomized, Placebo-Controlled Trial

Background

Pentoxifylline is a nonspecific phosphodiesterase inhibitor with anti-inflammatory properties. It reduces proteinuria in patients with glomerular disease, although its impact on glomerular filtration rate (GFR) is unknown. We hypothesized that pentoxifylline would slow the estimated GFR decrease in patients with chronic kidney disease at high risk of progression.

Study Design

Pilot randomized double-blind placebo-controlled trial.

Setting & Participants

40 outpatients with decreased GFR, hypertension, and proteinuria greater than 1 g/24 h currently treated with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or the combination and followed up in a nephrology clinic at a tertiary medical care facility.

Intervention

Pentoxifylline, 400 mg twice daily, or matching placebo.

Outcomes

Difference in rates of estimated GFR change during the 1-year study period between the 2 groups.

Measurements

Estimated GFR (4-variable Modification of Diet in Renal Disease Study equation) and proteinuria by 24-hour urine collection were assessed at baseline and 6 and 12 months after enrollment.

Results

Baseline characteristics were similar between the 2 groups. At 1 year, the mean estimated GFR decrease was significantly less in the pentoxifylline group than the placebo group (−1.2 ± 7.0 versus −7.2 ± 8.2 mL/min/1.73 m²/y; mean difference, −6.0 mL/min/1.73 m²/y; 95% confidence interval, −11.4 to −0.6; P = 0.03). For pentoxifylline-treated participants, the mean estimated GFR decrease during treatment was slower compared with the year before study enrollment (−9.6 ± 11.9 mL/min/1.73 m²/y; mean difference, −8.4 mL/min/1.73 m²/y; 95% confidence interval, −14.8 to −2.1; P = 0.01). Proteinuria was not different between the pentoxifylline and placebo groups at baseline, 6 months, or 1 year.

Limitations

Small sample size and incomplete follow-up.

Conclusions

Pentoxifylline may slow the estimated GFR decrease in high-risk patients. This may be independent of its antiproteinuric properties and warrants further investigation.

Index Words: Chronic kidney disease, estimated glomerular filtration rate, pentoxifylline, proteinuria, hypertension