Risk of Drug Interactions High in Cancer Patients
Most potential interactions involve non-cancer drugs
THURSDAY, April 19 (HealthDay News) -- About one-quarter of cancer patients are taking medications that could potentially interact with other drugs, and non-cancer therapeutics such as warfarin and anti-hypertensives are most likely to be a problem, according to a study in the April 18 issue of the Journal of the National Cancer Institute.
Monika K. Krzyzanowska, M.D., M.P.H., from Princess Margaret Hospital in Toronto, Canada, and colleagues used a questionnaire to survey 405 adult cancer patients with solid tumors regarding medications they had taken in the past 4 weeks.
The researchers identified 276 potential drug interactions, of which 9 percent were of major severity (risk of death), and 77 percent were of moderate severity (risk of serious health problems). About a quarter of patients (27 percent) had at least one potential interaction. Most potential drug interactions (87 percent) involved drugs such as warfarin and anti-hypertensive drugs rather than anti-neoplastic agents. The risk of drug interactions increased with increasing numbers of medications being taken (odds ratio, 1.4 per additional drug), therapies for co-morbid conditions versus supportive care (OR, 8.6), and the presence of brain tumors.
"We suggest that patients at high risk, such as those receiving warfarin, anticonvulsants, and antihypertensive medications, be routinely screened for potential drug interactions," Krzyzanowska and colleagues concluded. "The development of medication databases and computerized physician medication order entry linked to screening electronic programs could help health professionals to identify dangerous drug combinations and monitor prescriptions of agents with high risks of interactions such as anticonvulsants and warfarin."