TREATMENT OF MAC LUNG DISEASE REQUIRES A MULTI-DRUG REGIMEN (MORE THAN ONE DRUG).
- MAC is resistant to ordinary antibiotics.
- Combination of 3 drugs (all FDA approved)/dosages are based upon your clinical history, age, weight, and symptoms.
- Clarithromycin (Biaxin) or Azithromycin (Zithromax)
- Rifampin (Rifadin) or Rifabutin (Mycobutin)
- Ethambutol (Myambutol)
- The combination of medicines is given until no more MAC germs can be grown by culture of your sputum for 1 year. Average treatment period is about 15-18 months.
- Monthly sputum cultures are performed while you are on therapy and periodically when you finish your therapy to be sure your MAC is gone.
- The 3-drug treatment may be given 3 times weekly (preferably Monday-Wednesday-Friday) or daily.
- Data from previous treatment trials tells us that most patients (approximately two-thirds) who have no previous treatment of their MAC and who can tolerate the appropriate medicines will get better and be “cured” of their MAC lung disease.
- Patients who have failed a prior drug regimen of > 6 months for their MAC are more likely to fail the standard drug regimen (almost 50%).
- Patients who take the 3-drug regimen for less than 1 year with negative cultures are more likely to relapse with disease with their same MAC strain.
- Patients who fail therapy after taking the 3 medicines are usually required to take additional medicines. Injectables which may be useful include:
- Streptomycin or Amikacin
- Amikacin can also be given by inhalation (aerosolized) and is less toxic when given in this manner.
- Monthly laboratory blood tests that include a complete blood count and comprehensive metabolic panel (CBC and CMP) to check for possible damage to blood cells, kidneys, and liver.
- Most common potential side effects/complications of medicines:
- Clarithromycin : Loss of appetite, diarrhea, nausea, abdominal pain, abnormal liver function tests (blood tests), bitter taste, mild allergic rash.
- Azithromycin : Diarrhea, nausea, abdominal pain, abnormal liver function tests (blood tests), decreased hearing, tinnitus (sounds in ears).
- Rifampin : Nausea, vomiting, liver damage, decreased platelets (cells which clot blood), body secretions (urine primarily) are orange/red.
- Rifabutin : Nausea, vomiting, decreased platelets, decreased white blood cells (cells that fight infection), eye pain (uveitis), diffuse muscle and joint aches, skin pigmentation (yellow).
- Ethambutol : Decrease in vision (especially color vision), blurriness.
- Streptomycin : Kidney damage, sounds in ears (tinnitus), hearing loss, poor balance, numbness, tingling, muscle damage, fever, headache.
- Amikacin : Kidney damage, tinnitus, hearing loss, poor balance.
If you experience these or other additional problems, you should discuss them with your physician.
- Amikacin by inhalation (aerosolization) decreases toxicity to above adverse events.
Provide a list of your current medicines to your physician so he can determine any possible contra-indications.
PULMONARY FUNCTION TESTING
What is a pulmonary function test?
Pulmonary function testing is a way to measure your breathing capacity and, therefore is an objective measure of how well you are breathing. There are several types of breathing tests that can be done during pulmonary function testing including spirometry, lung volumes and diffusing capacity. A technician will explain what you need to do during each test and will coach you during the tests to help you give a good effort. All breathing tests require more than one measurement so that you will be asked to make more than one effort for each test. Spirometry is the most commonly performed breathing test. It requires you to take in as deep a breath as possible and then blow out the air in your lungs as forcefully and fully as possible. Spirometry, therefore, measures how much air you breathe in and out and how fast you breathe air in and out. Spirometry is frequently performed at baseline and then after you have inhaled a bronchial dilating drug (breathing medicine) to evaluate the effect of medication on your breathing function. As with all pulmonary function tests, it is very important that you make a maximal effort to insure accurate assessment of your breathing function. Lung volumes are performed while you are sitting in a small chamber called a plethysmograph (or body box) and provide further information about how much air you breathe in and out. You will be asked to perform different breathing techniques such as blowing into a tube while in the chamber. Lung volumes are usually not performed unless there are abnormalities found on spirometry. The diffusing capacity is one measure of how well your lungs move oxygen from the lungs into the blood. The results of pulmonary function testing can tell you and your doctor how much your lungs have been affected by a disease process and help determine if specific therapy can be of benefit to you. They can also be useful for evaluating the effects of a disease or treatment over time. You will be given specific instructions about what to do with your own breathing medications when the breathing tests are scheduled. Pulmonary function testing usually takes between ½ to 1 ½ hour to complete, depending on how many of the pulmonary function tests you are asked to complete.
Also see the http://www.uthct.edu website for further information including on how to arrange a clinic visit for expert consultation on MAC. Other centers that can also provide such consultation are found under the List of Treating Institutions.