Drug Used to Treat Arrhythmia may Increase Cancer Risk: Study

Amiodarone, a drug used to treat arrhythmia, can raise the risk of cancer, especially in older patients, according to a new study.

Arrhythmia is a disorder with the rate and beats of the heart. The heartbeat may be too fast, slow or irregular.

According to Medline Plus, amiodarone, the drug approved in 1985 to treat the condition, has been linked with lung cancer and liver damage, and in some cases the drug is even known to worsen arrhythmia. The drug is fat-soluble and degrades very slowly, leading to accumulation of the drug in the body.

For the study, researchers obtained data from 6,418 individuals who were using the drug. The research team, led by Vincent Yi-Fong Su, M.D., of the Taipei Veterans General Hospital in Taiwan, tracked these people for over two years, during which 280 participants had developed cancer.

Study results showed that patients who were male or those who received high doses of the drug within the first year of the heart condition had a high risk of cancer. After accounting for other factors that may have affected the results such as age, sex and disease, researchers found that people with high levels of the drug were twice as likely to develop cancer as people who were taking low doses of the drug.

"We suggest that cancer events should be routinely reported in future amiodarone trials, and further observational research is necessary. Also, when prescribing amiodarone, doctors need to keep in mind that this medication may increase cancer risk," Su said in a news release.

The study is published in the journal Cancer.