Suspected duloxetine-induced restless legs syndrome phenotypic variant: a case report

TL;DR

A 67-year-old woman developed restless arms syndrome after increasing duloxetine, which improved with dosage reduction and dopaminergic treatment.

Contribution

Highlights duloxetine as a potential inducer of RLS variants and suggests a treatment approach combining dose reduction and dopaminergic drugs.

Findings

Duloxetine dose increase triggered RLS-like symptoms in a patient with a history of RLS.

Symptoms resolved with duloxetine dose reduction and pramipexole addition.

No recurrence was observed six months after discharge with the adjusted treatment.

Abstract

Restless arms syndrome (RAS) is the most common variant of restless legs syndrome (RLS), which is easy to be ignored in clinical practice due to the lack of specific diagnostic criteria. When effective therapeutic agents induced RAS and symptoms persisted after briefly observation, clinicians will face the challenge of weighing efficacy against side effects.

A 67-year-old woman was admitted to a geriatric psychiatric ward with depression. Upon admission, the escitalopram dose was reduced from 15 mg to 10 mg per day, and the duloxetine dose was increased from 60 mg to 80 mg per day. The next night before bedtime, she developed itching and creeping sensations deep inside bilateral shoulders and arms, with the urge to move, worsening at rest, and alleviation after hammering. The symptoms persisted when escitalopram was discontinued. A history of RLS was confirmed. Treatment with 40 mg of duloxetine and 0.125 mg of pramipexole significantly improved depression, and the paresthesia disappeared, with no recurrence occurring 6 months after discharge.

This case suggests that psychiatrists should pay attention to RLS variants when increasing doses of duloxetine. Long-term improvement can be achieved through dosage reduction combined with dopaminergic drugs instead of immediate discontinuation.

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