Losses are up at Pozen (Nasdaq: POZN), but there are qualifiers. 

The Chapel Hill-based drug firm reports a loss of $8.4 million for the first quarter, up from $5.7 million a year ago. However, sales of the arthirtis drug Vimovo are growing.

Plus, Pozen revenues don’t include royalties from another pain reliever, Treximet, which it sold to another firm.

Pozen said Tuesday before the markets opened that it received $1.3 million in revenues from Vivomo from partner AstraZeneca. That’s up from $400,000 a year ago.

For all of 2011, Vimovo revenues were $2.9 million. In 2010 they were $50,000.

Revenues a year ago were $4.5 million, including Treximet royalties from GlaxoSmithKline (NYSE: GSK).

Expenses declined to $9.8 million from $10.2 million a year earlier/

Operating expenses for the first quarter of 2012 totaled $9.8 million, as compared to $10.2 million for the comparable period in 2011. The slight decrease in operating expenses in the first quarter of 2012 was primarily a result of the completion of the PA32540 Phase 3 studies, partially offset by higher pre-commercialization expenses for PA32540.

Pozen’s one-time sale of royalties to Treximet lifted Pozen to a net profit of $42.3 million or $1.40 per share for 2011, the company said in February.