Azithromycin is a commonly used antibiotic made by Pfizer, Inc., and sold as Zithromax®. Many people have taken this drug to treat pneumonia, sore throats or ear infections.
In 1999, the Cystic Fibrosis Foundation recognized that azithromycin might help people with cystic fibrosis (CF) who have a positive sputum culture for Pseudomonas aeruginosa (Pseudomonas) and designed a clinical trial to test that possibility.
The results of the clinical trial showed that azithromycin helped people with CF. Their lung function improved, they had fewer pulmonary exacerbations (lung infections) and they were able to gain more weight.
The CF Foundation also supported a clinical trial to see if azithromycin can help improve the health of kids with CF who do not have Pseudomonas. The result of this 6-month clinical trial was recently published in the May 5, 2010, issue of the Journal of the American Medical Association (JAMA).
Recently, a laboratory study published in the Journal of Clinical Investigation, suggested a possible link between the use of azithromycin and an increased risk of infection with nontuberculous mycobacteria (NTM).
So you may be asking: What does this mean for me or my child? Here is some information that can help you talk to your CF healthcare provider to see if you or your child should be taking azithromycin regularly.
What were the results of the first trial, for those people with Pseudomonas?
During the first clinical trial, lung function (FEV1), weight, use of antibiotics and days spent in the hospital to treat lung infections were watched for changes. The people with CF who were involved in the study were split into two groups. One group took a placebo — an inactive pill that has no treatment value (sometimes called a sugar pill). The other group took azithromycin.
During this trial, neither the patients nor the CF researchers knew which patients took azithromycin or placebo pills. Over six months, the group that took the azithromycin had about a 6 percent improvement in their lung function, fewer pulmonary exacerbations, took fewer antibiotics (other than azithromycin) and had an increase in their weight. They also spent 47 percent fewer days in the hospital for the treatment of a lung infection.
back to top
What were the results of the second clinical trial for kids without Pseudomonas?
During the second clinical trial, lung function (FEV1), weight and lung infections were watched for changes. The people with CF who were involved in the study were split into two groups. One group took a placebo — an inactive pill that has no treatment value (sometimes called a sugar pill).
The other group took azithromycin. During this trial, neither the patient nor the CF researchers knew who took which. Over six months, the group that took the azithromycin had fewer exacerbations, took fewer oral antibiotics and had an increase in their weight.
Lung function was about the same in those who took placebo and those who took azithromycin. However, the people in the azithromycin group reported less coughing than the group taking the placebo.
back to top
Were there any side effects?
The side effects found in both studies were mild. In the study of people with Pseudomonas, those on azithromycin had more nausea, diarrhea and wheezing.
In the study of kids without Pseudomonas, those on azithromycin did NOT have more side effects. A few people had side effects that made the researchers reduce the amount of the drug that they took.
back to top
What does the study in the Journal of Clinical Investigation mean for people with CF?
A research article in the September 1, 2011, issue of the Journal of Clinical Investigation suggested that long-term use of the antibiotic azithromycin by people with CF might increase the risk of an infection with nontuberculous mycobacteria (NTM). NTM can cause lung problems in people who have CF.
However, this study was done in the laboratory and did not involve testing in people, including those with CF. Therefore, what it means to someone with CF is not yet known. The CF Foundation is working with the world’s experts in this area to determine if there is a potential risk for people with CF and what should be done.
back to top
Is azithromycin right for me or my child?
Your CF health care team can help answer this question. Knowing who was chosen for the clinical trials might help you decide if azithromycin is right for you or your child.
In the first study, the people with CF had a positive culture for Pseudomonas for at least one year, were 6 years of age or older, weighed at least 55 pounds and had mild to moderate lung disease. If a patient had a sputum culture that contained nontuberculous mycobacteria (NTM) or Burkholderia cepacia complex (B. cepacia), or had liver disease or kidney disease, they were not included in the trial.
In the second study, the kids with CF did not have Pseudomonas for at least one year, were 6 to 18 years of age and had mild to moderate lung disease, although most had mild lung disease. If a patient had a sputum culture that contained NTM or B. cepacia, or had liver disease or kidney disease, they were not included in the trial.
Your CF health care team can provide you with more information. If you are thinking about starting azithromycin, you or your child should have sputum cultures done to see if there is NTM in the sputum. Blood tests should also be done to see if there are signs of liver or kidney disease. These tests are important to help your CF health care team know if azithromycin is right for you or your child.
back to top
Who should NOT take azithromycin?
Anyone who is allergic to azithromycin, erythromycin or any macrolide-related antibiotic, should not take azithromycin. People with liver disease, pregnant women and those with a positive culture for nontuberculous mycobacteria (NTM) need to talk with their CF health care team before starting azithromycin.
back to top
What are nontuberculous mycobacteria (NTM)?
Non-tuberculous mycobacteria are a type of bacteria found in the environment and sometimes cause lung infections in people with CF. Lung infections from this type of bacteria are not passed from one person to another and can be treated with the proper medications. However, if you have NTM in your sputum, it could affect your doctor’s decision about whether to start you on azithromycin. Ask your CF health care team for more information or if you have concerns.
Talk to your CF doctor BEFORE you stop any medication that has been prescribed for you or your child.
back to top
What about other medications?
If you take antacids (such as Mylanta®, Maalox®), take them two hours before or four hours after the azithromycin is taken. As with any medication, you should tell your CF health care team what over-the-counter vitamins, herbals and other CF drugs you or your child are taking.
back to top
How is azithromycin taken?
Azithromycin is a tablet that can be taken with food. In clinical trials, people with CF took one or two azithromycin pills on Monday, Wednesday and Friday. How many pills one person takes is based on how much the person weighs.
back to top
Should people with CF who are taking azithromycin stop taking other CF drugs?
Azithromycin is just one more “tool” that can be used in CF care. It may be used as a part of your or your child’s regular CF treatment. It is not meant to replace other proven CF drugs. Do not stop any therapy before you talk with your CF health care team. It is always a good idea to talk about all of your therapies with your CF health care team to make sure that you or your child are getting the proper treatment.
back to top
What happened to the germs or bacteria in the lungs of the people in the trial?
In the first study in people with Pseudomonas, there was no change in the germs. More studies are planned to figure out exactly how azithromycin works in CF.
back to top
What about antibiotic resistance?
People can — and do — become resistant to antibiotics that are taken over a long time. This did not seem to happen in the azithromycin clinical trials. Your CF health care team will watch for signs of resistance to azithromycin and any other antibiotics.
back to top
Was the CF Foundation involved in the trials?
The CF Foundation worked with the principal investigators to conceive, design and initiate both clinical trials to bring azithromycin to people with CF. In addition to providing the funds to do the studies, the CF Foundation supported the CF Therapeutics Development Network involving CF Foundation-accredited care centers that participated in these clinical trials.
To find a cure for this disease, the CF Foundation follows the approach of pursing several different strategies. It continues to invest millions of dollars in science that uses the latest technology to discover new CF-specific drugs.
At the same time, the azithromycin studies are a part of a “low-hanging fruit” strategy to study the potential of drugs already on the market for other diseases that may have a benefit for people with CF.
Your participation is essential in the process of developing new drugs and making them available sooner for everyone with CF. The CF Foundation thanks all of the patients and acknowledges the efforts of the physicians, research coordinators, study leaders and Pfizer who made this clinical trial a success.
back to topUpdated 9/22/2011
