Pulmonary tuberculosis - New and future therapeutic aspects

The duration of treatment of pulmonary tuberculosis caused by non-resistant tubercle bacilli, was shortened by combination treatment with pyrazinamide. The classical treatment regimen lasting 9 months and comprising the daily administration of isoniazid 5 mg/kg, rifampicin 10 mg/kg, and ethambutol 20 mg/kg over a period of 2 months, followed by isoniazid and rifampicin over the next 7 months has now been replaced by a shortened regimen that lasts for 6 months. This latter comprises the daily administration of the above-mentioned antituberculous drugs, with the addition of pyrazinamide 30 mg/kg, and isoniazid and rifampicin over the following 4 months. With this 'short regimen', as in the case of the classical therapeutic regimen, the relapse rate is of the order of 1%, even in cases of initial resistance to isoniazid. In the event of acquired resistance to isoniazid and rifampicin, two therapeutic strategies are possible: 1. discontinuation of treatment to await the results of resistance testing; 2. administration of a number of antibiotics that are continued until the results of testing are known. The new quinolones (perfloxacin, ofloxacin) and the derivatives of rifamycin SV (LM 427 or ansamycin) open up new therapeutic perspectives, not merely for the cases of multi-resistant tuberculosis, but also for mycobacterioses. Patients with negative tuberculosis culture profit from a treatment regimen of even shorter duration (2-3 months), comprising a combination of isoniazid, rifampicin and pyrazinamide.