Mycobacterium Xenopi Medication

Updated: Oct 14, 2019
  • Author: Mansoor Arif, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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Medication Summary

Optimal therapy for M xenopi is not established. Response to therapy varies and does not always correlate with the results of in vitro susceptibility testing. Physicians use combination therapy, with 2-4 drugs prescribed from several months to up to 18 months. M xenopi disease should always be treated with at least 2 active drugs because single-drug therapy increases the probability of acquired resistance.



Class Summary

Therapy must be comprehensive and cover all likely pathogens in the context of the clinical setting.

Clarithromycin (Biaxin)

Probably most important drug. To avoid development of resistance, should not be used as monotherapy. Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest.

Ethambutol (Myambutol)

Probably second most important drug. Diffuses into actively growing mycobacterial cells (eg, tubercle bacilli). Impairs cell metabolism by inhibiting synthesis of one or more metabolites, which in turn causes cell death. No cross-resistance demonstrated. Mycobacterial resistance is frequent with previous therapy. Use in these patients in combination with second-line drugs that have not been administered previously. Administer q24h until permanent bacteriologic conversion and maximal clinical improvement is observed. Absorption is not altered significantly by food.

Rifabutin (Mycobutin)

Ansamycin antibiotic derived from rifamycin S. Inhibits DNA-dependent RNA polymerase, preventing chain initiation in susceptible strains of Escherichia coli and Bacillus subtilis but not in mammalian cells. If GI upset, administer dose bid with food.


For treatment of susceptible mycobacterial infections. Use in combination with other antituberculous drugs (eg, isoniazid, ethambutol, rifampin). Total period of treatment for tuberculosis is minimum of 1 y; however, indications for terminating therapy may occur at any time. Recommended when less potentially hazardous therapeutic agents are ineffective or contraindicated.

Rifampin (Rifadin)

Probably an important drug for treatment. For use in combination with at least 1 other antituberculous drug. Inhibits DNA-dependent bacteria but not mammalian RNA polymerase. Cross-resistance may occur.

Azithromycin (Zithromax)

Similar to clarithromycin but may allow once-per-wk dosing.

Levofloxacin (Levaquin)

For treatment of tuberculosis in combination with rifampin and other antituberculosis agents.