The early bactericidal activity of amikacin in pulmonary tuberculosis.
METHODS
Stellenbosch University, a tertiary care hospital in Cape Town, South Africa.


OBJECTIVE
To determine the early bactericidal activity (EBA) of amikacin in dosages of 5 mg/kg, 10 mg/kg and 15 mg/kg body weight in comparison to that of isoniazid 6 mg/kg body weight or no drug.


METHODS
An open, randomised trial.


METHODS
Patients with previously untreated, sputum smear-positive pulmonary tuberculosis.


METHODS
Patients received amikacin 5 mg/kg (12 patients), 10 mg/kg (13 patients) or 15 mg/kg (15 patients), isoniazid 6 mg/kg (9 patients) or no drug (10 patients).


RESULTS
The rate of decrease in log viable colony forming units of Mycobacterium tuberculosis per ml of sputum per day during the first 2 days of treatment with amikacin 5 mg/kg, 10 mg/kg and 15 mg/kg was 0.041 (SD 0.100), 0.045 (SD 0.144) and 0.052 (SD 0.096), respectively, 0.515 (SD 0.173) in the patients receiving isoniazid 6 mg/kg, and 0.041 (SD 0.113) in those receiving no drug. The EBA found in patients receiving amikacin did not differ significantly from that of the no drug group. However, as the EBA in the no drug group was the highest ever encountered at Stellenbosch University, the mean in patients receiving drug was tested against 0 and found to differ significantly (P = 0.03), suggesting minimal activity. Mean amikacin serum concentrations 1 hour after intramuscular drug administration were 13.5 microg/ml, 26.7 microg/ml and 39.2 microg/ml in the patients receiving 5 mg, 10 mg and 15 mg per kg body weight, respectively.


CONCLUSIONS
Despite serum concentrations well in excess of the minimal inhibitory concentration of 2-4 microg/ml, the EBA of amikacin in patients with smear-positive pulmonary tuberculosis was only just detectable.
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
Mitchison
D A
DA
D000293:Adolescent; D000328:Adult; D000583:Amikacin / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D000995:Antitubercular Agents / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use; D015169:Colony Count, Microbial; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification; D013183:Sputum / Q000382:microbiology; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000188:drug therapy* / Q000382:microbiology
D000900:Anti-Bacterial Agents; D000995:Antitubercular Agents; D000583:Amikacin; D007538:Isoniazid