[Pharmacokinetics of sulfalene and sulfamethoxine after combined administration with benzylpenicillin and ampicillin]. / Farmakokinetika sul'falena i sul'fadimetoksina pri kombinirovannom primenenii s benzilpenitsillinom i ampitsillinom.

The binding of sulfadimethoxine by serum proteins of rabbits did not change in the presence of benzylpenicillin and ampicillin, while the binding of sulfalen increased. The 1.2-2-fold decrease in the proportion of sulfalen not bound by blood proteins was accompanied by its acetylation in rabbits. This in its turn resulted in a decreased rate of the drug elimination. The penicillins did not change the kinetics of sulfadimethoxine in rabbits. When the dose of sulfadimethoxine was increased 2 times, the rate of its elimination in rabbits increased, which is likely to be due to increased acetylation of the drug. This may be associated with the increased level of the free sulfadimethoxine fraction in the blood because of the drug lower binding by serum proteins. When the dose of sulfalen was increased 2 times, its kinetics in rabbits did not change.