The likelihood that the sleep disorder drug Zopiclone had side-effects that contributed to James Louie killing his children and trying to kill his wife is extremely unlikely, court heard on Wednesday.
Martin Davies, an expert in bio-chemistry and pharmacology, with a special emphasis in the mechanism by which Zopiclone exerts its effect on humans, said such side-effects as amnesia and aggression are extremely rare.
"The initial indication is it has fewer side-effects than other similar medications," Davies told Crown prosecutor Beverley Bauer. "Zopiclone also leaves the system rather rapidly."
The Crown called Davies in response to the defence’s claim through other medical experts that the trigger for the deadly incident on Nov. 27, 2009, could have been Zopiclone (also known as Imovane).
Dr. Liya Xie had testified last week it is possible Louie overdosed on the drug, which he had been prescribed by his family doctor four days before the killings.
She said the stresses and depression from his marital troubles and losing partial custody of his children were not enough to trigger the murders.
"He didn’t have all these things (that caused him) to kill, until he overdosed," Xie said. "It’s more likely than not that he took more Imovane than he said he did."
Police were not able to find the bottle to determine how much of the drug was left, court heard. He had recalled taking only six of the 30 pills he was prescribed by his family doctor on Nov. 23, 2009.
Three other doctors also came to similar conclusions, primarily based on the fact Louie took more medication than he remembered taking.
Louie, 45, is on trial for first-degree murder for strangling Jason, 13, and Jane, 9, and attempting to do the same to his estranged wife, Ying Tang, at the family home in Panorama Hills N.W.
The defence is trying to prove he was suffering from a mental disorder at the time of the killings and, thus, should be found not criminally responsible.
Davies said in an extensive study in France involving 20,000 patients who took therapeutic amounts of Zopiclone (7.5 mg.), the most common side-effect was a bitter taste.
The 1991 study, he said, concluded only about .02 per cent of the participants reported aggression. It is not known if any, or how many of them, ever acted upon the aggression.
Also, he said, only .07 per cent of them had any memory issues.
"They are very rare (side-effects)," said Davies. "I could not find any verified cases of Zopiclone inducing violent behaviour."
Davies also said there were "almost no cases" of patients forgetting everything that happened to them while on the drug, as Louie has told doctors.
Under cross-examination by defence lawyer Noel O’Brien, Davies agreed that in the large overdose cases, it was unknown if there were any psychiatric issues.
He also said care should be taken when giving Imovane to people with depression. Court has heard Louie has no memory of the event, from before he killed the children until many hours after he tried to strangle his wife at least eight hours later.
The expert said in cases where a naive user takes a large amount of the pills, such as the 24 the defence is suggesting Louie may have taken, it is often done for suicide.
Still, the side-effects are not likely to be aggression, but extreme drowsiness.
Dr. John Poon, Louie’s family doctor who treated him on Nov. 23, 2009, prescribed Imovane and referred him to a psychiatrist but determined he was otherwise normal.
Poon also said the patient was not disoriented, confused or out of touch with reality and he did not notice anything strange about his behaviour.
The trial before Court of Queen’s Bench Justice Earl Wilson continues.
Calgary Herald
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