Health trends

New lymph node mapping agent approved

The United States Food and Drug Administration (FDA) recently approved Lymphoseek (technetium Tc 99m tilmanocept) Injection, a radioactive diagnostic imaging agent that helps doctors locate lymph nodes in patients with breast cancer or melanoma who are undergoing surgery to remove tumour-draining lymph nodes.

Lymph nodes filter lymphatic fluid that flows from the body's tissues. This fluid may contain cancer cells, especially if the fluid drains a part of the body containing a tumour. By surgically removing and examining the lymph nodes that drain a tumour, doctors can sometimes determine if a cancer has spread.

30-YEAR RECORD BROKEN

Lymphoseek is an imaging drug that helps locate lymph nodes. It is not a cancer imaging drug. Lymphoseek is the first new drug used for lymph node mapping to be approved in more than 30 years. Other FDA-approved drugs used for lymph node mapping include sulphur colloid (1974) and isosulfan blue (1981).

"Removal and pathological examination of lymph nodes draining a primary tumour is an important diagnostic evaluation for some patients with breast cancer or melanoma," said Shaw Chen, MD, deputy director of the Office of Drug Evaluation IV in the FDA's Center for Drug Evaluation and Research. "To use Lymphoseek, doctors inject the drug into the tumour area and later, using a handheld radiation detector, find lymph nodes that have taken up Lymphoseek's radioactivity."

Lymphoseek's safety and effectiveness were established in two clinical trials of 332 patients with melanoma or breast cancer. All patients were injected with Lymphoseek and blue dye, another drug used to help locate lymph nodes.

Surgeons subsequently removed suspected lymph nodes for pathologic examination. Confirmed lymph nodes were examined for their content of blue dye and/or Lymphoseek. Results showed Lymphoseek and blue dye had localised most lymph nodes, although a notable number of nodes were localised only by Lymphoseek.

Source: US Food and Drug Administration (FDA)

Azithromycin (Zithromax or Zmax) - risk of fatal heart rhythms

United States Food and Drug Administration (FDA) is warning the public that azithromycin (Zithromax or Zmax) can cause abnormal changes in the electrical activity of the heart that may lead to a potentially fatal irregular heart rhythm. Patients at particular risk for developing this condition include those with known risk factors such as existing QT interval prolongation, low blood levels of potassium or magnesium, a slower-than-normal heart rate, or use of certain drugs used to treat abnormal heart rhythms, or arrhythmias. FDA has issued a drug safety communication recently as a result of our review of a study by medical researchers, as well as another study by a manufacturer of the drug that assessed the potential for azithromycin to cause abnormal changes in the electrical activity of the heart.

FDA previously released a statement on May 17, 2012 about a study that compared the risks of cardiovascular death in patients treated with the antibacterial drugs azithromycin, amoxicillin, ciprofloxacin (Cipro), and levofloxacin (Levaquin), or no antibacterial drug.

The study reported an increase in cardiovascular deaths, and in the risk of death from any cause, in persons treated with a five-day course of azithromycin (Zithromax) compared to persons treated with amoxicillin, ciprofloxacin, or no drug. The risks of cardiovascular death associated with levofloxacin treatment were similar to those associated with azithromycin treatment. Azithromycin is marketed under the brand names Zithromax and Zmax.

Source: USFDA