The early bactericidal activity of streptomycin.
METHODS
Patients with sputum smear-positive, newly diagnosed pulmonary tuberculosis studied at Tygerburg Hospital, Cape Town, for their early response to streptomycin (SM).


OBJECTIVE
To determine the standard early bactericidal activity (EBA), namely the fall in viable counts of tubercle bacilli in 16-hour sputum collections during the first 2 days of treatment with SM.


METHODS
Patients were randomised to logarithmically spaced daily doses of 7.5, 15 or 30 mg/kg SM. A comparison by standard biological assay methods was then made with previous estimations of the EBA of paromomycin in doses of 7.5 and 15 mg/kg.


RESULTS
An EBA of 0.133 obtained with 30 mg/kg SM differed significantly from zero (P = 0.0009), while the EBAs of 0.043 with 15 mg/kg and -0.025 with 7.5 mg/kg did not so differ. A linear regression equation of EBA = -0.2587 + 0.2627 log10 dose was obtained with significant slope (P = 0.007). Paromomycin was estimated to be 1.745 more potent than SM with wide 95% confidence limits (0.6-28.6), indicating that it cannot be considered more potent than SM.


CONCLUSIONS
The low EBAs show that SM has low, dose-related, bactericidal activity in cavities, consistent with results from clinical trials. If streptomycin-resistant bacilli are present, paromomycin is probably the aminoglycoside of choice.
Donald
P R
PR
Department of Paediatrics, University of Stellenbosch, Cape Town, South Africa.
Sirgel
F A
FA
Venter
A
A
Smit
E
E
Parkin
D P
DP
Van de Wal
B W
BW
Doré
C J
CJ
Mitchison
D A
DA
D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000904:Antibiotics, Antitubercular / Q000627:therapeutic use*; D000995:Antitubercular Agents / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000627:therapeutic use; D008297:Male; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D010303:Paromomycin / Q000627:therapeutic use; D013183:Sputum / Q000382:microbiology; D013307:Streptomycin / Q000627:therapeutic use*; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy*
D000900:Anti-Bacterial Agents; D000904:Antibiotics, Antitubercular; D000995:Antitubercular Agents; D010303:Paromomycin; D007538:Isoniazid; D013307:Streptomycin