Quoted from http://www.reuters.com/article/idCNLDE68K0XS20100921
UK study links antipsychotic drugs to clot risk
Tue Sep 21, 2010 7:01pm EDT
By Ben Hirschler
LONDON, Sept 22 (Reuters) - Modern antipsychotic drugs, especially AstraZeneca's (AZN.L) blockbuster Seroquel, may increase the risk of patients developing life-threatening blood clots, British researchers said on Wednesday.
The finding, from a trawl of tens of thousands of patient records, adds to a growing body of evidence linking so-called atypical antipsychotics to adverse side effects.
Atypicals -- which also include Eli Lilly's (LLY.N) Zyprexa, Johnson & Johnson's (JNJ.N) Risperdal and Bristol-Myers Squibb's (BMY.N) Abilify -- dominate the antipsychotic market, which had sales of $16 billion in 2009, according to Thomson Reuters data.
First introduced more than 20 years ago, such drugs cause fewer of the involuntary-movement problems associated with older medicines but have been linked to diabetes and increased mortality in people with dementia.
There has also been limited evidence linking them with dangerous blood clots, such as deep vein thrombosis and pulmonary embolism, although previous studies have been small.
The large British study, which compared 25,000 cases of patients with venous thromboembolism (VTE) against 89,000 controls, found people prescribed antipsychotics had a 32 percent greater risk of serious blood clots, after adjusting for other potential risk factors.
The risk was greater for people on atypical drugs, rather than older ones, and the highest risk was seen with Seroquel, which showed a nearly three times increase on an adjusted basis.