Stroke risk same for newer dementia drugs as forerunners, Canadian study says
Feb. 28, 2005
TORONTO (CP) – Witnessing a once sweet-tempered loved one turn belligerent and physically aggressive is one of the most difficult aspects of dementia for family members to contend with. And although certain drugs can ease those symptoms, some doctors have been wary of prescribing them because of fears they may cause stroke. Patient trials have suggested that newer medications like risperidone and olanzapine, known as atypical antipsychotics, double the danger of strokes and other cardiovascular events compared with older antipsychotics like haloperidol. Now, Canadian researchers are challenging that view after a study of almost 33,000 patients found little difference in stroke risk between the newer antipsychotics and older “typical” versions. “The bottom line is if (doctors) are trying to decide on a drug treatment for one of their patients who has behavioural disturbance in dementia that they shouldn’t consider the risk of stroke as one of the influencing factors in deciding between an atypical and a typical antipsychotic,” said Dr. Sudeep Gill, lead investigator of the study by the Institute for Clinical Evaluative Sciences (ICES). The choice of drug is important, doctors say, because the newer antipsychotics are far less prone to cause Parkinson’s-like symptoms – including a shuffling gait, stooped posture and tremors – that are common among their forerunners. Still, it’s been difficult for doctors to prescribe the newer drugs with full confidence in the last several years, said Gill, a geriatrician at Queen’s University. In October 2002, Health Canada issued warnings about the atypical antipsychotics, saying they posed a danger of adverse cerebral-cardiovascular events like stroke after patient trials found that the rates doubled compared with taking a placebo, Gill said. The FDA followed suit in 2003 and the U.K.’s Committee on Safety of Medicines issued a warning early last year. “In the U.K., they came down very hard on risperidone and olanzapine, and the guidelines were actually amended . . . suggesting that patients with dementia who were on these drugs should be taken off them and they should not be used to manage behavioural disturbances,” Gill said from Kingston, Ont. That prompted ICES researchers to mount their own study, a review of hospital and drug records from 1997 to 2002 for 32,710 Ontario adults with dementia, about half of whom had been prescribed a newer antipsychotic and the rest one of the older class of drugs. Both groups had a similar risk of hospitalization for stroke – about 1.5 per cent for a first stroke and up to 6.5 per cent for a second one – concluded the study appearing in this week’s issue of the British Medical Journal. Behavioural and psychological symptoms from dementia include agitation, verbal aggressiveness and even violence. About two-thirds of dementia cases in Canada are associated with Alzheimer’s, and most patients with dementia will experience behavioural problems at some point during the course of their disease. “So, obviously for the patient, quality of life is a major problem,” said Gill. “For caregivers, it’s probably the largest problem: seeing behavioural disturbance can really be a major burden for them. “The people who we really try to aim these antipsychotic treatments at are the people who are very aggressive, in particular the people who have true psychosis, which is either hallucinations or delusions,” he said, noting that the drugs are also prescribed for schizophrenia. Dr. Howard Dombrower, a specialist at Baycrest Centre for Geriatric Care in Toronto, called the study “very important.” “If it’s true that the atypical neuroleptics cause strokes – and we’re still not certain of that – at least we’re reassured that we’re still better off using this newer class of medications than the older class because that problem may exist in them as well,” Dombrower said Thursday. Avoiding movement disorders associated with the older drugs, which can cause falls and reduced mobility, means a better quality of life for patients, he said. But both Dombrower and Gill stressed that these drugs should be used only as a last resort in patients with severe behavioural problems, which can’t be alleviated with other strategies, such as music therapy. The issue is particularly critical in nursing homes, where lack of staff means non-drug therapies aren’t always available to quell aggressive patients. “You can’t let a patient be violent to another patient or violent to a caregiver,” said Dombrower. “Even if there is a small increased risk of stroke (with the newer drugs), perhaps you have no choice.” Gill said he’s not sure why the ICES results are so different from previous studies. But he suspects it may be because more cardiovascular events, such as a sudden drop in blood pressure and mini-strokes, were included in the other studies’ criteria. “I think this is a really important issue that needs to get sorted out,” Gill said. “Our study is not the be-all and end-all. We’re going to have to get confirmation from other studies . . . so we’re not denying patients with dementia potentially a very good treatment on the basis of a misperception around the risk of stroke.”
source: Canadian Press
