The American Thoracic Society (ATS) recommends a standard treatment for pulmonary NTM disease of 3 or 4 FDA-approved drugs. These include Clarithromycin (Biaxin) or Azithromycin (Zithromax), Rifampin (Rifadin)or Rifabutin (Mycobutin) and Ethambutol (Myambutol), and Streptomycin or Amikacin (Amikin).
Occasionally the standard therapy will fail. In that case, medications may be added or changed.
Amikacin is from a class of medications called aminoglycosides. It cannot be taken orally; it is administered by injection or intravenously. Common side effects from taking amikacin include sounds in the ear (tinnitus), hearing loss, poor balance, and kidney damage/failure. Rarely a rash might occur. Injected Amikacin tends to be more toxic and is more expensive.
Periodically there are shortages of this medication. Click here for the latest information on shortages and ordering instructions for pharmacists.
Rifampin is taken orally in pill form. Many patients experience slight changes in liver function tests while taking rifampin. Other side effects such as gastrointestinal upset, fever, flushing, and itching without rash may also occur. Blood abnormalities such as a decrease in the blood cells that aid in clotting (platelets) known as thrombocytopenia may occur. Rarely, patients may develop a worsening of kidney function.
Rifampin pills are orange in color, and because this color is absorbed in the body, body fluids may temporarily appear orange or red for several hours after taking the medicine. People taking rifampin should not wear soft contact lenses, as the lenses will permanently absorb the orange discoloration. Extremely high doses of rifampin may cause a condition known as “Redman syndrome.” Symptoms generally begin within 5 or 10 minutes of receiving the drug, and include itching and flushing of the face, neck and torso, and less frequently, swelling of the lips, face, or eyes, or a drop in blood pressure.
Ethambutol is a pill administered according to the patient’s weight in kilograms. The most significant side effect of ethambutol is associated with nerves; this includes inflammation of the optic nerve (optic neuritis). Patients often complain of blurry vision and often have problems with red-green color discrimination. This tends to occur on high daily doses of the medicine. (Allergic reactions may occur on any drug dosage of the medicine.)
Optic neuritis usually improves slowly over months. Patients taking ethambutol should have baseline eye tests performed before starting the medication and should contact their physician promptly if symptoms of blurry vision or other eye problems occur. Less frequently, patients experience gastrointestinal upset, skin rash or irritations, fever, and muscle aches.
Azithromycin is an alternative macrolide drug to clarithromycin taken in pill form. Some patients who can’t tolerate clarithromycin may be able to take azithromycin. Side effects may include diarrhea and gastrointestinal upset, hearing loss and tinnitus. These are generally reversible when the drug is stopped or with lower drug doses.
Clarithromycin is a macrolide drug that is well absorbed in pill form. The most common side effects are metallic or bitter taste, loss of appetite, nausea, vomiting, and diarrhea. Abnormalities in liver enzymes may also occur, usually in patients on higher dosages.
Clarithromycin should never be taken alone or combined only with a quinolone drug (includes ciprofloxacin and levofloxacin) for the treatment of MAC because of the risk of developing drug resistance.
Streptomycin is given by injection. The main side effects are problems with balance and auditory (ears) toxicity. Patients taking streptomycin should be aware of decreased hearing, tinnitus, and problems with balance, numbness or tingling, fever and headache. Kidney damage may also occur, as well as changes in blood counts, so these should be routinely monitored while on this drug.
Streptomycin is not readily available in all pharmacies. It is generally given to patients with severe disease, or who have failed the standard drug regimen.
Clofazimine (Lamprene) has been used in the past primarily to treat leprosy (Mycobacterium leprae). However, it is sometimes used to treat patients with MAC, especially with drug resistant strains of MAC or patients who have failed standard therapy.
Gastrointestinal upset including loss of appetite (anorexia), diarrhea, and abdominal pain are the most common side effect.
Dry mouth and skin may occur, and in rare cases, patients may experience skin discoloration.
Clofazimine is no longer commercially available, and requires special application to the FDA to get approval for its use.
For more information on applying to the FDA for Clofazimine use, click here.
Quinolone antibiotics such as ciprofloxacin, levofloxacin (levaquin), gatifloxacin (tequin), and moxifloxacin (avelox), are sometimes used in the treatment of MAC, even though their effectiveness is less than optimal. Patients should not take a quinolone alone or with just zithromax or biaxin. Side effects including dizziness, diarrhea, nausea, and significant weight loss are not uncommon. Their efficacy is not widely known in the treatment of MAC.
In patients who take rifampin initially and do not see an improvement in the infection, rifabutin is considered as a replacement for rifampin.
Information about these drugs courtesy of maclungdisease.org.
Log on to maclungdisease.org for information about dosages