Objective: To assess the impact of iron loading on the activity of isoniazid and ethambutol in the treatment of murine tuberculosis.
Design: Iron-loaded and iron-normal female Balb/C mice infected with 1.5 x 10(7) colony forming units of Mycobacterium tuberculosis were treated with either isoniazid or ethambutol for 28 days.
Results: For both treatments, the outcome was impaired by the iron loading: bactericidal activity of isoniazid was partially but significantly reduced and ethambutol bactericidal activity was totally inhibited.
Conclusion: The treatment of tuberculosis in patients with iron loading should be longer than for normal patients or should contain an additional drug.