1975 Volume 23 Issue 6 Pages 2073-2079
The results of some studies on amikacin were summarized as follows;
1. The minimum inhibitory concentration (MIC) of 23strains of Pseudomonas aeruginosa which were clinically isolated distributed in the range from 0.73 μg/ml to 25 μg/ml and the peak of MIC was 3.13.μ9/ml.
2. Tissue concentration of amikacin in rats after intramuscular injection (20 mg/kg) was measured by means of cup plate method using Bacillus subtilis PCI-219 as test organism and the value was the highest in serum, lowering in order in kidney, lung and liver, among which the latter's concentration was especially poor. The peak was obtained after 30 minutes of the administration.
3. The blood concentration following an intramuscular injection of 100 mg of amikacin was determined in 4 normal adults. The blood concentration reached the peak after 1/2-1 hour, exhibiting a considerable individual difference. The peak of serum levels of amikacin given intramuscularly at adose of 200 mg in a cross over experiment was 14.7 μg/ml after 30 minutes and was about twice of that of given 100 mg of amikacin.
4. As to amikacin sputum concentration after its intramuscular injection, the value was the highest in the sputa which were reserved from injection time to 3 hours after administration and its value was 1.8 μg/ml. The peak concentration in sputum was 26% of the peak concentration in serum. Incomparison with the ratio of penicillin groups which were 1 × 5%, the transition of amikacin in sputum is better than that of penicillin groups.
5. Amikacin was applied at a dose of 100-300 mg daily for 3-44 days to 10 cases of the internal infections. Seven cases of respiratory infections (bronchiectasis 1, chronic bronchiolitis 1, pneumonia 3, bronchopneumonia 1, chronic obstructive lung disease 1) and two cases of suspected hepatic abscess and one case of peritonitis were treated with amikacin and the results obtained were effective in 3 cases, slightly effective in 1 case, ineffective in 2 cases and undecided in 4 cases. Though amikacin was administered intramuscularly to 4 cases over 25 days, no particular side effects were observed. The reason of low percentage of effective case may probably be attributed to the associated severe underlying diseases in most of our cases.
