From the Guidelines
For non-tubercular mycobacterial (NTM) infections of the GI tract causing diarrhea, clarithromycin is the preferred first agent, as it has been studied more extensively and appears to be associated with more rapid clearance of MAC from the blood 1. When considering treatment options, several factors come into play, including the potential for drug interactions, intolerance, and the efficacy of the medication against the specific NTM causing the infection.
- The recommended regimen typically includes clarithromycin at a dose of 500 mg twice daily, usually combined with other antimycobacterial drugs to prevent or delay the emergence of resistance 1.
- Azithromycin can be substituted for clarithromycin when drug interactions or clarithromycin intolerance preclude the use of clarithromycin 1.
- Testing MAC isolates for susceptibility to clarithromycin or azithromycin is recommended for all patients to ensure the most effective treatment regimen 1.
- It's essential to consider the potential side effects and drug interactions of the chosen regimen, as well as the need for regular monitoring to ensure the treatment's efficacy and safety.
- The most common NTM causing GI infections is Mycobacterium avium complex (MAC), and clarithromycin has demonstrated excellent activity against these organisms 1.
- Treatment should continue until symptoms resolve and cultures remain negative for at least 12 months, with regular monitoring for side effects and adjustments to the treatment regimen as needed.
From the Research
Comparison of Clarithromycin and Azithromycin
- Both clarithromycin and azithromycin have been used to treat non-tuberculous mycobacterial (NTM) infections, including those causing diarrhea in the GI tract 2.
- However, the choice between these two antibiotics depends on various factors, including the specific species of NTM, the severity of the infection, and the patient's overall health.
Efficacy of Clarithromycin and Azithromycin
- Clarithromycin and azithromycin have been shown to be effective against several NTM species, including Mycobacterium avium complex, Mycobacterium kansasii, and Mycobacterium genavense 2.
- Azithromycin, in particular, has been used as part of a combination therapy regimen for the treatment of NTM infections, including those caused by Mycobacterium avium complex 3.
Treatment Challenges
- NTM infections are often difficult to treat due to their intrinsic multidrug resistance and the limited efficacy of existing treatments 4, 3.
- The treatment of NTM infections requires a prolonged course of antibiotics, which can be challenging for patients to tolerate 5, 6.
- The development of new therapeutic strategies, including the use of alternative antibiotics and combination therapy regimens, is urgently needed to improve treatment outcomes for NTM infections 4, 3.
Specific Considerations for GI Tract Infections
- The treatment of NTM infections in the GI tract, including those causing diarrhea, requires careful consideration of the specific species of NTM and the patient's overall health 6.
- A combination therapy regimen that includes clarithromycin or azithromycin may be effective for the treatment of NTM infections in the GI tract, but the optimal treatment approach is not well established 2, 3.