Rosamicin in Urethral and Vaginal Secretions and Tissues in Dogs and Rats

Abstract

In animal studies we investigated the distribution of rosamicin in plasma and urethral and vaginal tissues in rats as well as in urethral and vaginal secretions in dogs. We found concentration ratios between urethral secretion and plasma of 1.9 and between vaginal secretion and plasma of 2.4. The rosamicin concentrations in urethral and vaginal tissue significantly exceeded the levels of all other tissues investigated. Because rosamicin could be valuable for the treatment of bacterial urethritis and the colonization of the vaginal introitus with fecal bacteria in women, it should be investigated clinically in this respect.The mode of secretion by the female paraurethral glands, also called Skene's glands or female prostate, as well as the diffusion across the vaginal epithelium (7) and the cervical excretion (4) seems to have many analogies to the production of prostatic secretion in males (3). The therapy of chronic urethritis or the colonization of the vaginal vestibule with fecal bacteria, preceeding urinary tract infections, represents a problem comparable to that of prostatitis.In animal studies we investigated the distribution of rosamicin (rosamicin sodium dihydrogen phosphate was supplied by Schering Corp., Bloomfield, N.J.) in plasma and urethral or vaginal secretions and tissues. Rosamicin is a new basic macrolide antibiotic with good activity against gram-positive as well as gram-negative bacteria, chlamydia, and mycoplasms (9).Previous bacteriological in vitro studies have shown relatively low minimum inhibitory concentrations of rosamicin against a large number of gram-negative microorganisms, even in a moderately acid medium (5), suggesting the possible treatment of nongonococcal urethritis or the colonization of the vaginal vestibule by the most commonly involved bacteria, such as enterobacteriaceae, especially Escherichia coli (1, 8).MATERIALS AND METHODS Six adult female dogs weighing between 11.2 and 18.2 kg were anesthetized intravenously with sodium thiopental, and the urethra was ligated at the bladder neck to prevent urine contamination. The vagina was exposed through a speculum, and blank paper disks for bioassay determinations were inserted into the urethra and the vagina with a small thread attached, making them easily retrievable.After 5 min in situ, they were removed and placed on a streptomycin assay agar to determine their rosamicin concentrations by a disk diffusion method, usingBacillus subtilis as the test organism.At the same time, blood samples were drawn for bioassay determinations. Pilocarpin, 4 mg, was given intravenously immediately before the antibiotic administration to stimulate the vaginal and urethral secretions. An intravenous bolus of rosamicin (10 mg/kg of body weight) was administered followed by a continuous infusion of 3 mg/kg per h for 4 h. Blood samples were drawn, and the disks were applied immediately after the bolus injection and after 30, 60, 120, 180, and 240 min.To determine the rosamicin tissue concentrations of the urethra and the vagina in rats, we used...

High-pressure liquid chromatographic method for determination of rosaramicin in humans

“…Rosaramicin is a micromonospora-produced macrolide antibiotic with activity against both gram-positive and gram-negative bacteria (1,3,7). After oral or intravenous administration, plasma and serum concentrations ofrosaramicin in humans (1) and laboratory animals (1,6) were low and often below the detectable limits of a microbiological assay (0.1 to 0.2 ,ug/ml).…”

In Vitro Susceptibility of 30 Strains of Chlamydia trachomatis to Rosamicin

“…The antibacterial spectrum and the high levels of the drug which were found in vaginal secretions and tissues of dogs and rats and in prostates of humans after experimental administration of the antibiotic (3, 8) suggested that rosamicin might be useful in the treatment of genitourinary infections.…”