Sisomicin Explained

Sisomicin (bactoCeaze, ensamycin, and initially antibiotic 6640^[1] and rickamicin), is an aminoglycoside antibiotic, isolated from the fermentation broth of Micromonospora inositola.^[1] It is a newer broad-spectrum aminoglycoside most structurally related to gentamicin.

Sisomicin is the most predictably active aminoglycoside against Gram-positive bacteria.^[2] Like most other aminoglycosides, sisomicin is bactericidal for sensitive clinical isolates. The minimum bactericidal concentrations (MBC) have been found to be equivalent or very close to the minimum inhibitory concentrations (MIC).^[3] Like other aminoglycosides, most clinical isolates of Pseudomonas aeruginosa remain susceptible to sisomicin. Resistance to sisomicin may be enzymatically or non-enzymatically mediated. Sisomicin is inactivated by the same enzymes as gentamicin, but it is active against many organisms that resist gentamicin by non-enzymatic mechanisms.^[4]

Some studies show that sisomicin has been effective in the treatment of infections that either had failed to respond to other drugs or were due to microorganisms resistant in vitro to other aminoglycosides.^{[5] [6]}

Notes and References

1. Weinstein MJ, Marquez JA, Testa RT, Wagman GH, Oden EM, Waitz JA . Antibiotic 6640, a new Micromonospora-produced aminoglycoside antibiotic . The Journal of Antibiotics . 23 . 11 . 551–4 . November 1970 . 5487129 . 10.7164/antibiotics.23.551 . free .
2. Sanders WE, Sanders CC . Sisomicin: a review of eight years' experience . Reviews of Infectious Diseases . 2 . 2 . 182–95 . Mar–Apr 1980 . 6994206 . 10.1093/clinids/2.2.182 .
3. Levison ME, Kaye D . In vitro comparison of four aminoglycoside antibiotics: sisomicin, gentamicin, tobramycin, and BB-K8 . Antimicrobial Agents and Chemotherapy . 5 . 6 . 667–9 . June 1974 . 15825423 . 429032 . 10.1128/aac.5.6.667 .
4. Phillips I, King BA, Shannon KP . Journal of Antimicrobial Chemotherapy . 4 . 2 . 121–9 . March 1978 . 649532 . 10.1093/jac/4.2.121 . The mechanisms of resistance to aminoglycosides in the genus Pseudomonas .
5. Keating MJ, Bodey GP, Valdivieso M, Rodriguez V . A randomized comparative trial of three aminoglycosides--comparison of continuous infusions of gentamicin, amikacin and sisomicin combined with carbenicillin in the treatment of infections in neutropenic patients with malignancies . Medicine . 58 . 2 . 159–70 . March 1979 . 431401 . 10.1097/00005792-197903000-00004 . 1035277 . free .
6. Maki DG, Craig WA, Agger WA . A comparative clinical trial of sisomicin and gentamicin in major gram-negative infections . Infection. 7 . S298–S300 . Jun 1979 . 10.1007/bf01646260. 46971853 .