Effects of L-carnitine on dialysis-related hypotension and muscle cramps: a meta-analysis

Am J Kidney Dis. 2008 Nov;52(5):962-71. doi: 10.1053/j.ajkd.2008.05.031. Epub 2008 Aug 15.


Background: L-Carnitine is an endogenous compound thought to be helpful in treating patients with dialysis-related hypotension and muscle cramps; however, sufficient evidence for these indications is lacking.

Study design: Systematic review and meta-analysis.

Setting & population: Adult patients with end-stage renal disease receiving long-term hemodialysis.

Selection criteria for studies: All published English-language reports of randomized placebo-controlled trials of L-carnitine supplementation in adult long-term hemodialysis patients.

Intervention: Supplemental L-carnitine (or placebo) for at least 8 weeks.

Outcome: Random-effects pooled odds ratio for intradialytic cramping or hypotension in L-carnitine-treated participants.

Results: Of 317 potentially relevant articles, 7 (total enrollment of 193 patients) met criteria for inclusion. Four articles reported results for both hypotension and cramps, 1 had results for only hypotension, and 2 reported results for only cramps. Using data from all 6 relevant trials, the pooled odds ratio for cramping after L-carnitine supplementation was 0.30 (95% confidence interval, 0.09 to 1.00; P = 0.05). Analysis of the 5 studies examining the response of intradialytic hypotension to l-carnitine supplementation yielded a pooled odds ratio of 0.28 (95% confidence interval, 0.04 to 2.23; P = 0.2).

Limitations: The small number of available studies yielded limited statistical power. In addition, there was considerable interstudy heterogeneity.

Conclusions: Although suggestive in the case of muscle cramping, the available evidence does not confirm a beneficial effect of L-carnitine supplementation on dialysis-related muscle cramping or intradialytic hypotension. Additional study in the form of large rigorous randomized trials is needed in both cases.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Carnitine / therapeutic use*
  • Humans
  • Hypotension / drug therapy*
  • Hypotension / etiology*
  • Muscle Cramp / drug therapy*
  • Muscle Cramp / etiology*
  • Renal Dialysis / adverse effects*


  • Carnitine