The Food and Drug Administration has issued a in patients with blood or lymph node cancers who have received donor stem cell transplants.
This use of azithromycin can lead to increased risk of cancer relapse and death in this population. The FDA is continuing to review data and is expected to issue further recommendations.
Patients with blood or lymph node cancers are at an increased risk of bronchiolitis obliterans syndrome after donor stem cell transplant; although azithromycin is not approved for prevention of this condition, the antibiotic is sometimes prescribed for that purpose.
A French study of 480 patients was undertaken to assess the effectiveness of this prophylaxis but revealed the increased risk of relapse and death and was halted 13 months after completing enrollment. The rate of cancer relapse was 32.9% in the azithromycin group and just 20.8% in the placebo group; the 2-year survival rate was 56.6% in the azithromycin group and 70.1% in the placebo group (JAMA 2017;318[6]:557-66).
Bronchiolitis obliterans syndrome is marked by inflammation and scarring of the airways that leads to severe shortness of breath and dry cough. There are no known effective antibiotic treatments for prophylaxis of the condition, according to the FDA.
FDA officials are advising physicians not to prescribe long-term azithromycin in this population. Patients who have had a stem cell transplant and are already taking the antibiotic, should consult a doctor before discontinuing.
The manufacturer of brand name azithromycin (Zithromax) has issued a Dear Healthcare Provider letter about the safety issue, and more information can be found in the FDA’s safety announcement.