Local Gentamicin Research Articles

Gentamicin???PMMA Beads

Five patients treated with gentamicin-polymethylmethacrylate (PMMA) beads were monitored during the treatment of nine to 14 days. Kinetic data of the gentamicin delivery were gathered constantly by multiple samples of blood and urine. The treatment with 48-360 beads caused a gentamicin serum concentration of 0.03-0.4 micrograms/ml and a renal excretion rate of 3-40 micrograms/min. The total amount of gentamicin excreted after the whole treatment was 20%-70%, with an in vivo half-life of 5.7-10 days. The gentamicin appeared to be released constantly during the entire treatment (nine to 14 days); the beads are kinetically slow release carriers. Despite precise measurement of tubular and glomerular renal function, no nephrotoxicity could be demonstrated. This local antibiotic gentamicin therapy may use the blood bone barrier effectively as a protection of the body against a very high local gentamicin concentration.

Local gentamicin in the care of extensive burns

Summary Gentamicin sulphate applied to burns as a o·I per cent. ointment was not successful in delaying contamination with Pseudomonas pyocyanea in patients with pyo-prone burns. Gentamicin sulphate applied as a 0·3 per cent, cream was successful in delaying the onset of Ps. pyocyanea infection. Both applications were successful in preserving surviving skin elements in large deep dermal burns to an extent which had not been anticipated. Absorption of the drug into the blood stream was significant, especially if applied on the day of burning, but in no case approached toxic levels. The authors are convinced that 0·3 per cent. gentamicin cream is a valuable application for large burns.

Activity of gentamicin against Pseudomonas and hospital Staphylococci.

Gentamicin is a new basic antibiotic complex isolated from an actinomycete, Microrn?nospora purpurea, in the Research Laboratories of the Schering Corporation, New Jersey. It consists of two components, referred to as gentamicin Q and gentamicin C2, which are closely related in structure and have a similar antibacterial spectrum. Both substances contain a 2-deoxystreptamine component and are chemically related to the streptomycin group of antibiotics (Rosselet et al., 1963). Gentamicin is supplied as the sulphate, which is a white powder readily soluble in water. Gentamicin has been shown to be bactericidal in vitro against a wide range of Gram-positive and Gram-negative bacteria, including hospital drug-resistant strains of Staphylococcus aureus and coliform bacilli, and has outstanding activity against Pseudomonas pyocyanea (see White, 1963 ; Weinstein et al., 1963 ; Rubenis et al., 1963 ; Rabinovich et al., 1963). Early clinical trials showed that the antibiotic is effective in the treatment of infections of the urinary tract due to many Gram-negative bacilli, including Ps. pyocyanea (Bulger et ed., 1963 ; Jao and Jackson, 1963 ; Bray ton and Louria, 1964 ; Klein et al., 1964), but if the blood level rises to about 15 /xg./ml. or more there is a danger of severe vestibular damage (Jao and Jackson, 1964). Stone et al. (1964, 1965) reported the successful treatment of severe burns with Ps. pyocyanea septicaemia, both systemic treatment and local gentamicin ointment being used. The present investigation was undertaken in order to compare the activity of gentamicin with that of other streptomycin-like antibiotics against strains of Staph. aureus and coliform bacilli isolated in a British hospital.