SPI

Ferritina menor 75 o 75-100

Saturación Transferrina menor 20-25%

IRON REPLACEMENT THERAPY. Iron supplementation should be prescribed if the

serum ferritin level is less than 75 ng/mL, the transferrin saturation is less than

20% to 25%, or both. The recommended dose is 65 mg of elemental iron, twice a

day 1 hour before a meal.17 Ferrous sulfate 325 mg, twice daily, is the most

common form of oral iron used, although ferrous fumarate can also be used. This

can be combined with 100 mg to 200 mg of vitamin C for better absorption.17-19

Gastrointestinal adverse effects from oral iron include nausea and constipation.

Oral iron may help mild RLS symptoms but may not be effective for severe RLS.

If oral iron is not tolerated or effective, IV iron can be considered. Low-

molecular-weight iron dextran is recommended due to the low risk of

anaphylaxis.17,19,20 Symptom improvement with IV iron can occur after 2 to

4 weeks but could take up to 6 weeks.17,19 Of the low-molecular-weight IV iron

formulations available, ferric carboxymaltose 1000 mg infused over 1 hour has

the most evidence for the treatment of RLS, is considered first-line treatment,

and has been shown to improve RLS symptoms in those with serum ferritin levels

less than 100 ng/mL and transferrin saturation less than 45%.19 Other

formulations such as IV iron sucrose and low-molecular-weight iron dextran can

be used but have less evidence for efficacy.19 Serum ferritin levels and transferrin

saturation should be reassessed 12 weeks posttreatment with oral iron and 8 to

16 weeks posttreatment with IV iron.19 CASE 7-1 illustrates how iron

supplementation is incorporated into RLS treatment.