Survey finds drugs often incorrectly prescribed
By Sharon Gray
(L-R) Drs. Gerry Mugford and Terrence Callanan are members
of the Canada-U.S. Maine Benzodiazepine Study Group. Dr. Mugford is chair
of the epidemiology and policy stream. (Photo by HSIMS).
A survey to assess benzodiazepine prescribing patterns of doctors in Maine found that many patients are given long-term prescriptions for this class of drugs, despite established guidelines that recommend they be used for no more than a month.
“The survey focused on reasons to prescribe this drug class as well as how physicians’ personal prescribing patterns reflect established guidelines,” said Dr. Gerry Mugford, an assistant professor of Pharmacy, Medicine and Psychiatry at Memorial, and chair of the epidemiology and policy stream of the Canada-U.S. Maine Benzodiazepine Study Group.
“We found differences between general practitioners and specialists, older versus more recent medical graduates, rural versus urban prescribing patterns and gender differences among prescribing physicians.”
The first benzodiazepine in 1959 was chlordiazepoxide (librium). Since then, physicians have increasingly prescribed a variety of benzodiazepines rather than the older and more-addictive barbiturates for problems such as insomnia and anxiety. Although guidelines state that benzodiazepines should not be prescribed for more than 30 days, Dr. Mugford said the Maine survey found that a large number of patients have been on these drugs for more than 90 days, with some taking them continuously for up to 20 years.
“They are often used inappropriately and we believe that the North American prevalence of 10 per cent use is very under-reported,” Dr. Mugford said. “There is no hard evidence that long-time benzodiazepine use helps the patient. On the contrary, it is often implicated in hip fractures, traffic accidents, adverse drug events and suicides.”
Physicians prescribe benzodiazepines for anxiety, insomnia, depression, movement disorder, alcohol withdrawal, muscle relaxation and grief reaction. Dr. Mugford said that women, especially poor women over 65, have prescribing and usage rates of about 20 per cent. “We have observed rates in some female population samples up to three times that that of the general population.”
The Maine survey of approximately 190 physicians found that over 96 per cent of them currently prescribe benzodiazepines. Factors such as pressure from well-educated patients, and from emotionally-upset patients who have been on benzodiazepines a long time, can influence their decision to prescribe the drugs. “A large number of physicians use their own personal judgment rather than official guidelines in their decision to prescribe. In our survey, 87 per cent had given benzodiazepine prescriptions beyond 90 days and a major reason they gave was chronic anxiety although there is little evidence to suggest benzodiazepines are an effective treatment for this condition.”
The survey found that general practitioners or family doctors were more likely to prescribe benzodiazepines than psychiatrists, and most likely to prescribe ativan, valium and restoril. The survey asked the physicians which benzodiazepines they were prescribing, with a list of 14 to choose from. Some added in drugs which they thought were benzodiazepines but which weren’t.
Family doctors were more likely to be influenced by manufacturing information than psychiatrists, although when it came to prescribing beyond 90 days there was no difference in the reasons given between family doctors and psychiatrists. Female doctors reported a higher rate of prescribing for “grief reaction” and were less likely to prescribe beyond 90 days. “Female physicians gave more reasons for prescribing benzodiazepines and were more influenced by side effects and drug interactions.”
Dr. Mugford said although the survey sample was small, it represented a variety of ages, a range of community sizes in urban and rural areas, and was gender balanced. “We see this as a pilot study and it is evident a broader-based survey would be useful. We need to explore the attitudes physicians have towards guidelines and why they don’t follow them. We have a major concern over the use of benzodiazepines in seniors because of drug interaction when the dose is increased because of tolerance.”
Memorial University is the academic centre for three streams of the Canada-U.S. Maine Benzodiazepine Study Group. Dr. Terrence Callanan, chair of the Discipline of Psychiatry, is a founding member and senior academic partner of the group, which started four years ago. Dr. Mugford has been a member of the Maine group for three years and was recently appointed chair of the epidemiology and policy stream.
Dr. Mugford and fourth-year Memorial psychiatry resident Dr. Anjana Chawla attended the third annual Maine Benzodiazepine Study Group International Conference held last fall in Bangor, Maine. Dr. Chawla won the Resident Award at this meeting for her paper on imovane (zopiclone), a short-acting sedative-hypnotic used in the short-term treatment of insomnia. Dr. Chawla showed that imovane can be addictive in some patients.