Merck & Co, embroiled in its second litigation case concerning its one-time blockbuster Vioxx (rofecoxib) [[01/10/04a]], has hit a stumbling block in opening its defence after the judge threatened to throw out a key testimony.

The case, which started three weeks ago, involves Vietnam war veteran Frederick Humeston, who suffered a heart attack in 2001 and attributes this to being given Vioxx for tendonitis [[16/09/05b]]. Merck’s defence lawyers, however, contend that his heart attack was predisposed by stress or other underlying health factors.

According to an Associated Press report, Briggs Morrison – a Merck researcher – testified that studies conducted in both animals and humans had shown a “neutral” effect of Vioxx on the heart. However, it transpired that Dr Morrison was not involved in all the investigations, leading the prosecution to complain that he was not in fact an expert on the studies in question.

Merck’s attorney, Stephen Raber, takes a different view, telling Reuters: “To have this testimony struck is about as unfair as anything I can think of.” Judge Carol Higbee will rule on the testimony on Monday.