[A case of pneumonia caused by Mycobacterium avium complex successfully treated with clarithromycin].

We reported on a 79-year-old woman with pneumonia caused by Mycobacterium avium complex (MAC). She was admitted with fever, general fatigue, and cough. A chest X-ray film showed infiltrative shadows in the right lung field. In spite of administration of conventional antibiotics, the infiltrative shadows enlarged. A chest CT scan revealed areas of consolidation and ground glass opacities. Bronchoalveolar lavage (BAL) examination revealed an increased number of lymphocytes. Transbronchial lung biopsy revealed many granulomatous regions with giant cells. Mycobacterium intracellulare was found in the culture of BAL fluid and identified by PCR. Treatment was started with rifampicin, ethambutol, and clarithromycin. However, rifampicin and ethambutol were soon discontinued because of severe anorexia. Her symptoms and the radiographic appearance markedly improved following treatment of clarithromycin alone. Subsequently small doses of rifampicin and ethambutol were restarted because her general condition was much improved. These findings suggest that clarithromycin is an effective and tolerable agent for elderly patients with MAC.