Effect of a carbonaceous oral adsorbent on the progression of CKD: a multicenter, randomized, controlled trial

Am J Kidney Dis. 2009 Sep;54(3):459-67. doi: 10.1053/j.ajkd.2009.05.011. Epub 2009 Jul 17.


Background: The carbonaceous oral adsorbent AST-120 slows the deterioration of kidney function in patients with advanced chronic kidney disease (CKD). However, information about AST-120 in patients with less severe stages of CKD is lacking.

Study design: Randomized controlled trial.

Setting & participants: 75 medical facilities, 460 patients with CKD with serum creatinine (sCr) concentrations less than 5.0 mg/dL (not undergoing dialysis).

Intervention: Random assignment to either a low-protein diet and antihypertensive medication in the control group or that treatment combined with AST-120 (6 g/d).

Outcomes & measurements: Composite primary end point: doubling of sCr level, increase in sCr level to 6.0 mg/dL or more, need for dialysis or transplantation, or death.

Secondary outcomes: adverse events and changes in estimated creatinine clearance (CCr) rate, proteinuria (protein in milligrams per day), and quality of life.

Results: Mean sCr level was 2.66 mg/dL and estimated CCr was 22.4 mL/min in both groups. During 56 weeks, numbers of primary end-point events (43 for control versus 42 for AST-120) and event-free survival (P = 0.9) did not differ between groups. Gastrointestinal adverse events were less common in the control group than the AST-120 group (2 versus 32 events). Estimated CCr decreased more in the control group than in the AST-120 group (-15% per year versus -12% per year, relative to the baseline value; [corrected] P = 0.001). Median proteinuria changed from protein of 1,162 to 1,167 mg/d in the control group versus 1,102 to 906 mg/d in the AST-120 group (P = 0.2).

Limitation: Infrequent primary end-point events.

Conclusion: AST-120 did not substantially slow the progression of kidney disease in patients with moderate to severe CKD during 1 year.

Trial registration: ClinicalTrials.gov NCT00456859.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adsorption
  • Aged
  • Carbon / administration & dosage*
  • Carbon / pharmacokinetics
  • Creatinine / blood
  • Disease Progression*
  • Endpoint Determination / trends
  • Female
  • Follow-Up Studies
  • Humans
  • Kidney Failure, Chronic / blood*
  • Kidney Failure, Chronic / drug therapy*
  • Kidney Failure, Chronic / pathology
  • Male
  • Middle Aged
  • Oxides / administration & dosage*
  • Oxides / pharmacokinetics


  • Oxides
  • Carbon
  • AST 120
  • Creatinine

Associated data

  • ClinicalTrials.gov/NCT00456859