What is the recommended next step in managing refractory restless legs syndrome in a patient whose gabapentin and pregabalin have failed and whose ferritin level is 100 µg/L?

Refractory RLS Management After Alpha-2-Delta Ligand Failure

For refractory RLS with ferritin at 100 µg/L where gabapentin and pregabalin have failed, you should initiate extended-release oxycodone or another opioid as your next-line therapy. 1

Treatment Algorithm

Step 1: Optimize Iron Status First

Even though your patient's ferritin is 100 µg/L, the 2025 AASM guidelines recommend iron supplementation when ferritin is below appropriate levels. While 100 µg/L is above the traditional threshold, consider:

• IV ferric carboxymaltose (strong recommendation, moderate certainty) 1
• Alternative IV iron formulations (ferumoxytol, low molecular weight iron dextran) if ferric carboxymaltose is unavailable 1
• Target ferritin levels above 100 µg/L, ideally 75-100 ng/mL minimum 2

This is critical because iron plays a central role in RLS pathophysiology, and optimizing iron status may enhance response to other therapies 3.

Step 2: Initiate Opioid Therapy

Since both alpha-2-delta ligands (gabapentin and pregabalin) have failed, opioids are the recommended next step 1. The 2025 AASM guidelines specifically suggest:

• Extended-release oxycodone (conditional recommendation, moderate certainty of evidence) 1
• Other opioids are also acceptable alternatives 1

Why opioids now? The evidence hierarchy has shifted dramatically. The 2025 guidelines explicitly recommend against standard use of dopamine agonists (pramipexole, ropinirole, rotigotine) due to augmentation risk 1. While dopamine agonists may provide short-term relief, they carry significant long-term risks that outweigh benefits in most patients 4, 3.

Step 3: Consider Adjunctive Dipyridamole

The guidelines suggest dipyridamole as an option (conditional recommendation, low certainty) 1. This could be added to opioid therapy if monotherapy proves insufficient.

Step 4: Non-Pharmacologic Option

Bilateral high-frequency peroneal nerve stimulation is suggested as an alternative (conditional recommendation, moderate certainty) 1. This device-based approach may be considered for patients who cannot tolerate or prefer to avoid opioids.

What NOT to Do

Avoid dopamine agonists as standard therapy. The guidelines explicitly recommend against routine use of:

• Pramipexole 1
• Ropinirole 1
• Rotigotine 1
• Levodopa 1

These agents carry high augmentation risk—a paradoxical worsening of RLS symptoms that can be devastating and difficult to reverse 4, 3. If you must use them, only consider for short-term use in patients who prioritize immediate symptom relief over long-term safety 1.

Also avoid:

• Cabergoline (strong recommendation against) 1
• Bupropion, carbamazepine, clonazepam, valproic acid 1

Key Clinical Pearls

Augmentation awareness: The dramatic shift away from dopamine agonists in 2025 reflects growing recognition that augmentation is not just a side effect—it's a treatment-limiting complication that can make RLS worse than the original disease 4, 3.

Iron is foundational: Even with "normal" ferritin, RLS patients may benefit from higher iron stores. The pathophysiology involves central nervous system iron deficiency that may not be reflected in serum ferritin alone 2, 3.

Opioids are evidence-based: While opioid prescribing requires appropriate monitoring, these medications are highly effective for severe refractory RLS and can be safe and durable for long-term therapy when managed appropriately 5. The 2025 guidelines give them moderate certainty of evidence 1.

Refractory disease requires escalation: Your patient has failed first-line therapy (alpha-2-delta ligands). This is not the time for half-measures or agents with lower evidence quality. Move decisively to opioids while optimizing iron status 4, 3.