What are the effects of intravenous and oral iron compared with placebo for reducing restlessness in adults with restless legs syndrome?

CIAPPONI, AGUSTÍN

Cochrane Clinical Answers

Cochrane Clinical Answers

Año: 2019

Compared with placebo for adults with RLS, 1000 mg of intravenous iron, usually divided into multiple doses, or oral ferrous sulfate 325 mg given twice per day reduced International Restless Legs Scale (IRLS) severity scores by a mean of 3.78 points; however in some people, this may not have been clinically important (minimal clinically important difference of 3 points). Restlessness was clinically and statistically significantly reduced with iron compared with placebo (moderate‐certainty evidence for both outcomes). The effect of iron on quality of life was uncertain (very low‐certainty evidence), and there was little or no difference between groups for subjective sleep quality and for periodic limb movements during sleep. There was no clear evidence of a difference between iron and placebo for gastrointestinal adverse effects, although rates were higher in people taking iron (on average, 138 vs 96 per 1000 people). Lack of power in the analysis means that no conclusions can be drawn regarding comparative effects on withdrawals due to adverse events, withdrawals to use another RLS medication, or withdrawals due to inadequate symptom control.