Treatment of pulmonary disease caused by Mycobacterium kansasii: results of 18 vs 12 months' chemotherapy.

SETTING

Chest Clinic, Sant Pau Hospital, Barcelona, Spain.

OBJECTIVE

To assess the therapeutic response of pulmonary disease due to Mycobacterium kansasii to 12 and 18 months of chemotherapy.

DESIGN

28 patients with criteria of pulmonary disease caused by M. kansasii not associated with HIV-infection were identified in our department in the period 1985-91 (24 male, 4 female, mean age 56 +/- 12 years). 14 patients were treated with rifampicin-isoniazid-ethambutol daily for 12 months (ethambutol only for the first 6 months), and 14 with the same regimen for 18 months. The follow-up after treatment was 12-30 months.

RESULTS

All patients showed improvement of radiographic manifestation of disease and sputum conversion (mean time: 4.5 +/- 2 months). The adverse drug effects were minimal. No failures were detected, and only one patient (3.5%), in the group of 12-month chemotherapy, relapsed after finishing the treatment.

CONCLUSIONS

Our findings suggest that pulmonary disease due to M. kansasii has an effective response to 12-month chemotherapy regimen and that it is not necessary to prolong the administration of ethambutol for more than 6 months.