Table 3.
Clinical studies on IV iron substitution in RLS
| Type of Study | Number of Patients | Treatment Regime | Baseline Ft | Outcome | Other | |
|---|---|---|---|---|---|---|
| Nordlander et al.2 | IV iron, open label | 22 | N/A | 21/22 “responders” | ||
| Sloland et al.85 | IV iron dextran versus placebo, randomized, double‐blind | 11 versus 14 | 1,000 mg of iron dextran once | 87 (47–371) versus 175 (60–336) ng/mL | At 1 and 2 weeks, improved RLS score (7–4) in those treated, at 4 weeks, effect only marginal | 2‐degree RLS (all ESRD) |
| Earley et al.83, 88 | IV iron dextran, open label; IV iron gluconate for follow‐up | 10 (5 in follow‐up) | 1,000 mg of iron dextran once; 3× 150 mg of iron gluconate if symptoms and ferritin <300 ng/mL | 85.0 (±64.0) ng/mL | At 2 weeks, 6/10 “responders,” mean “response” time 11 months, 44% drop in PLMS/h, rapid decrease in Ft levels; 2 of 5 still on only IV iron after 130 weeks | MRI, actigraphy |
| Grote et al.90 | IV iron sucrose versus placebo, randomized, double‐blind | 29 versus 31 | 5× 200 mg of iron sucrose once | <45 ng/mL, 20.1 versus 20.4 ng/mL | At 7 weeks, IRLSSG score 12 versus 20 from 24, ESS did not improve; at 52 weeks, 80% IV iron versus 40% placebo without drugs | |
| Earley et al.89 | IV iron sucrose versus placebo, randomized, double‐blind | 11 versus 7 | 500 mg of iron sucrose once | 70 (±21) versus 78 (±47) ng/mL | At 2 weeks, placebo improved more (57% “responders”) | MRI, CSF, PSG |
| Ondo86 | IV iron dextran, retrospective analysis | 25 | 1,000 mg of iron dextran | 43.5 (±58.0) ng/mL | 73.9% reported some degree of improvement; duration of response ranged from 1 to 60 weeks | |
| Allen et al.91 | IV FCM versus placebo, randomized, double‐blind | 24 versus 22 | 2–3× 500 mg/1× 1,000 mg of FCM | 28.1/70.0 (F/M) versus 24.8/58.7 (F/M) | At 4 weeks,11 of 24 versus 1 of 22 “responders,” −9 versus −4 points on IRLSSG score, improved RLS‐QoL, PLMS/h and FSS not significantly different; treatment regimes all the same | Actigraphy |
| Hornyak et al.92 | IV FCM, prospective open label | 20 | 500 mg of FCM | <45 ng/mL; mean, 30.1 ng/mL | 60% reported some improvement of RLS symptoms (“responders”), IRLSSG score decreased by 10 points in “responders” | |
| Cho et al.87 | IV iron dextran, low molecular weight prospective, open label | 25 | 4× 250 mg of iron dextran | 41.0 (±37.0) ng/mL | 68% reported moderate to complete improvement of RLS symptoms, no correlation between “responder” status and serum and CSF Ft levels | CSF |
F, female, M, male, RLS‐QoL, RLS quality‐of‐life scale, FSS, fatigue severity scale.