[Pharmacokinetics of tobramycetin and gentamycin and the mechanism of their elimination by the kidneys]. / Farmakokinetika tobramitsetina i gentamitsina i mekhanizm vydeleniia ikh pochkami.

After subcutaneous administration of tobramycetin (tobramycin) to rabbits in single doses equivalent to the daily therapeutic doses for humans calculated for the body surface and those exceeding them by 3 times, the antibiotic was rapidly absorbed into the blood and detected within 30 and 72 hours respectively. Tobramycetin penetrated into all organs of the animals. Its highest levels were found in the kidneys and the lowest in the brain tissue. Tobramycetin was excreted with the urine in amounts equal to 80 per cent of the dose administered. No cumulation of the antibiotic was observed in the dog blood after its repeated subcutaneous administration. Comparative investigation of tobramycetin and gentamicin pharmacokinetics in rabbits after intravenous administration showed no significant differences. Both antibiotics were mainly excreted with the urine: the renal clearance averaged to 65 per cent of the total clearance, the time of a two-fold decrease in the blood levels of the antibiotics was on an average 40 minutes. Tobramycetin and gentamicin were excreted with the kidneys by means of glomerular filtration with insufficient reabsorption in the tubules.

[Toxicity, pharmacokinetics and pharmacodynamics of the Soviet bleomycin, bleomycetin, in a single administration to laboratory animals]. / Izuchenie toksichnosti, farmaokinetiki i farmakodinamiki otechestvennogo bleomitsina--bleomitsetina pri odnokratnom vvedeni laboratornym zhivotnym.

Toxicity of bleomycetin (bleomycin A2) administered intravenously, intraperitoneally, subcutaneously or intramusculary in a single dose to animals was almost identical. On its oral administration bleomycetin was 10--14 times less toxic than on its parenteral use. Rats were somewhat less sensitive to bleomycetin than mice. Bleomycetin had no significant effect on the level of the arterial pressure, respiration, ECG characteristics and elements of the vegetative nervous system in narcotized cats. After a single intravenous or subcutaneous administration to rabbits bleomycetin was detectable in the blood for 4--5 hours. The highest bleomycetin levels were registered in the skin, kidneys and lungs. Bleomycetin was mainly excreted with the urine.

[Action of antibiotic 1719 from a group of diazo compounds on hematopoiesis in laboratory animals and its pharmacokinetics]. / Deistvie antibiotika 1719 iz gruppy diazosoedinenii na krovetvorenie laboratornykh zhivotnykh i ego farmakokinetika

Antibiotic 1719 administered intravenously to rats in a single dose of 6.0 mg/kg induced a transitory decrease in the number of myelocariocytes on the 2nd-5th day of its use mainly at the account of decreased numbers of lymphoid elements. Simultaneously momentory leucopenia (granulocytopenia) and more stable lymphopenia were observed. When the antibiotic was administered intravenously to dogs in a dose of 0.9 mg/kg 4 times and in a dose of 0.4 mg/kg 40 times, an insignificant decrease in the number of myelocarlocytes was noted. Leucopenia, lymphopenia and thrombocytopenia in the peripheral blood almost completely disappeared after discontinuation of the preparation administration. Leucocytosis (granulocytosis), lymphopenia and thrombocytopenia were registered in the dogs and rabbits treated with the antibiotic in doses of 1.5 and 3.0 mg/kg 3 and 11 times respectively. When the antibiotic was added to the rabbit blood serum in concentrations of 0.5-5 gamma/ml, 70 to 80 per cent of the preparation bound with the blood proteins. After a single intravenous administration of antibiotic 1719 to rabbits in doses of 10 and 15 mg/kg, it was detected in the blood only for 5 to 15 minutes after the administration in concentrations not exceeding 0.3 and 0.5 gamma/ml. The antibiotic penetrated into all organs in small amounts and persisted there for 1.5 to 3 hours after the administration. The antibiotic was excreted with the bile in amounts of 0.3-0.5 per cent of the dose administered for 1 to 2 hours after a single administration. The antibiotic was excreted with the urine for 3-4 hours after the administration in amounts of 3.5 per cent after a single administration and 60-72 per cent after multiple administrations.