SILVER SPRING, Md. The Food and Drug Administration has approved a generic drug for treating restless leg syndrome, agency records show.

The FDA approved Alembic’s ropinirole hydrochloride tablets in strengths ranging from 0.25 mg to 5 mg.

The drug is a generic version of GlaxoSmithKline’s Requip. Several other companies also make generic versions of the drug. Requip and Requip XL had combined sales of around $500 million in 2009, according to GSK financial reports.