Lansoprazole as a possible trigger of restless legs syndrome with suspected periodic limb movement disorder in a hemodialysis patient: a case report.

Restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are common in patients undergoing hemodialysis and can significantly impair sleep and daily functioning. Several medications are known to induce or exacerbate RLS/PLMD, but proton pump inhibitors (PPIs) have not been clearly implicated. We report a hemodialysis patient with dopaminergic-refractory RLS/PLMD whose symptoms improved markedly following discontinuation of lansoprazole, suggesting a possible drug-related trigger. A 76-year-old woman with end-stage renal disease due to diabetic nephropathy began hemodialysis. Lansoprazole 15 mg/day was initiated two months earlier for peptic ulcer disease. Soon afterward, she developed irresistible leg discomfort and involuntary movements during rest and sleep, occasionally extending into daytime. Symptoms were relieved by movement and fulfilled the International RLS Study Group diagnostic criteria. Rotigotine therapy was ineffective, and symptoms gradually worsened. Laboratory findings showed preserved iron status, magnesium levels, and dialysis efficiency. Due to atypical daytime symptoms and dopaminergic refractoriness, drug-induced RLS/PLMD was suspected. Methyldopa, introduced later, was discontinued first, resulting in partial improvement. Subsequent withdrawal of lansoprazole and transition to vonoprazan led to near-complete symptom resolution within 14 days, with a reduction in the RLS-6 score from 28 to 4. The Naranjo score was 5, indicating a probable adverse drug reaction. This case suggests that lansoprazole may contribute to RLS/PLMD symptoms in susceptible hemodialysis patients. When RLS/PLMD presents atypically or responds poorly to dopaminergic agents, clinicians should reassess PPI necessity and consider structured withdrawal.