The U.S. Solicitor General has filed an amicus brief siding with two pharmaceutical sales reps in their overtime case against GlaxoSmithKline.

The lawsuit alleges that the company denied the reps overtime pay by improperly considering them outside salesmen. The term is defined by the Department of Labor, which also has definitions which distinguish between sales and promotional work.

The Solicitor General’s brief argues that the plaintiffs fall in the promotional category, because unlike salesmen, they cannot take orders, negotiate prices or determine a patient’s best interest – the latter being a physician’s job.

The brief concedes that drug reps could be considered salesmen, if only in a colloquial sense, “because they seek to persuade physicians.”

GSK has argued that the sales reps trigger sales, but the Solicitor General’s brief says that restrictions surrounding a drug rep’s practice make it “impossible to determine with certainty whether a PSR’s promotional work induced any particular prescription.”

Novartis settled a similar suit in January, for $99 million, and Schering-Plough was found to owe overtime pay in August.

The Supreme Court is set to hear the sales rep/GSK appeal this spring.