Management of Restless Legs Syndrome Based on Ferritin Levels

Introduction to RLS Management

• The American Academy of Sleep Medicine recommends iron supplementation in adults with RLS when serum ferritin is ≤75 ng/mL or transferrin saturation is <20%, using oral or IV iron; for ferritin between 75-100 ng/mL, only IV iron should be used; in children, supplement when ferritin is <50 ng/mL 1, 2

Testing Protocol

• Check serum iron studies (ferritin and transferrin saturation) in all patients with clinically significant RLS or PLMD, as recommended by the American Academy of Sleep Medicine 1, 2
• Blood draw should be performed in the morning after avoiding all iron-containing supplements and foods for at least 24 hours, according to the American Academy of Sleep Medicine guidelines 1, 2

Iron Supplementation Algorithm for Adults

• Use either oral iron (ferrous sulfate) or IV iron formulations for adults with ferritin ≤75 ng/mL or transferrin saturation <20%, as conditionally recommended by the American Academy of Sleep Medicine with moderate certainty of evidence 1, 2, 3
• Use ONLY IV iron formulations (not oral iron) for adults with ferritin 75-100 ng/mL, as recommended by the American Academy of Sleep Medicine 1, 2

Pediatric Iron Supplementation

• Supplement with oral or IV iron when serum ferritin is <50 ng/mL in children, as recommended by the American Academy of Sleep Medicine 1, 2

Special Population: End-Stage Renal Disease

• Different thresholds apply: supplement with IV iron sucrose if ferritin <200 ng/mL AND transferrin saturation <20% in patients with end-stage renal disease, as conditionally recommended with moderate certainty of evidence 4

Monitoring and Duration

• Continue iron supplementation indefinitely with ongoing monitoring, as RLS symptoms may recur if iron stores decline below therapeutic thresholds, as recommended by the American Academy of Sleep Medicine 3

Integration with Overall RLS Management

• Iron status assessment and correction should occur BEFORE or concurrent with pharmacological treatment, as recommended by the American Academy of Sleep Medicine 3
• Address exacerbating factors (alcohol, caffeine, antihistamines, serotonergic medications, antidopaminergics, untreated OSA) as the first management step, as recommended by the American Academy of Sleep Medicine 1, 2