The U.S. Solicitor General has filed an amicus brief taking the side of two pharmaceutical sales reps in the overtime case that they filed against GlaxoSmithKline.

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

The Solicitor General’s brief argues that the plaintiffs fall into 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 the drug reps could be considered salesmen, even 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 the restrictions which surround 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 suit similar to the GSK case in January, for $99 million, and Schering-Plough was found to owe overtime pay in August.

The Supreme Court is scheduled to hear the sales rep/GSK appeal in the session beginning on April 16.