MONDAY, April 16 (HealthDay News) -- Off-label prescribing of
medications is common, but the practice varies according to drug,
and patient and doctor characteristics, a Canadian study finds.
In off-label prescribing, a doctor prescribes drugs for uses
that have not been approved by regulators. For example, some
medicines approved to treat depression are also prescribed for
chronic pain.
The practice, which is legal but unregulated, is believed to
contribute to preventable medication-related harm in patients,
according to Dr. Tewodros Eguale, of McGill University in Montreal,
and colleagues.
For the study, they examined more than 250,000 electronic
prescriptions for more than 50,000 patients written from 2005
through 2009 by 113 doctors in a primary care network in
Canada.
The study results were released online in advance of print
publication in the journal
Archives of Internal Medicine as part of the journal's
health-care reform series.
About 11 percent of the medications were prescribed for
off-label use, and 79 percent of off-label use lacked strong
scientific evidence, the researchers found. The amount of off-label
use in this study was less than in a previous U.S. study, the
authors noted in a journal news release.
The investigators found that the highest rate of off-label use
involved central nervous system drugs (26 percent), anti-infective
agents (17 percent), and ear-nose-throat medications (15 percent).
The study also found that drugs with three or four approved uses
were less likely to be prescribed off-label than those with one or
two approved uses.
Medications approved after 1995 were less likely to be
prescribed off-label than those approved before 1981, and doctors
with high scores on evidence-based practice were less likely to
prescribe off-label, the findings showed.
"Our findings indicate that off-label prescribing is common in primary care and varies by drug class, the number of approved indications for the drug, the age of the drug, patients' sex and physicians' attitude toward evidence-based medicine," the researchers concluded.
"Electronic health records can be used to document treatment indication at the time of prescribing and may pave the way for enhanced post-marketing evaluation of drugs if linked to treatment outcomes," Eguale and colleagues wrote.
More information
The U.S. Agency for Healthcare Research and Quality has more
about
off-label prescribing.