Opening of antibiotics and emergence of such concept as antibacterial therapy, made a revolution in the world of medicine. Infectious diseases earlier not subject to mankind became sufficiently controllable. In parallel scientific and technical progress led to emergence everything new and more and more effective drugs. The profile of safety was improved and new forms of release of antibiotics were developed.
In parallel microorganisms improved the mechanisms of protection against antibacterial agents that brought and constantly leads to emergence of new, steadier mutations. Now it is possible to note safely that the speed of emergence and introduction of new antibacterial agents is not in time behind ability of microorganisms to adapt to them.
One of factors of development of stability to antibacterial drugs is their pharmacokinetics, namely concentration of drug in plasma. Fluctuations of plasma concentration allows microorganisms to develop stability mechanisms more easily. On the other hand, situations when purpose of antibacterial drugs is not shown rather often meet; in this case there is also forming of stability of the microorganisms which are in the patient's organism to this or that antibacterial drug.
The only indication to prescription of antibiotics is the proved infectious process. We can read this postulate in any grant where it is told about antibacterial therapy. But the problem is that in clinical practice not always just to define existence and the more so to claim about lack of infectious process. The differential diagnosis of symptoms of the inflammatory answer, such as hyperthermia, changes of level and a formula of leukocytes, increase in S-jet protein of a blood plasma can be difficult as they can be caused by both the infectious, and noninfectious reasons.
Very often the inefficiency of an antibioticotherapia is connected with the wrong dosing and the mode of administration of drug. Especially it concerns performing antibacterial therapy in the conditions of intensive care unit as the resuscitation patient has a pharmacokinetics of drugs in general, and antibacterial in particular, absolutely another. It is connected with change of speed of metabolism and elimination of drugs and also variations of volume of distribution at critical patients. For different antibacterial agents there are pharmacokinetics parameters differing from each other. As it was already mentioned above, fluctuations of concentration of an antibiotic in blood when it decreases below minimum suppressing for the activator, creates a window of selection and leads to stability forming. Besides, not always the peak concentration of drug received at periodic introduction appears enough to render therapeutic effect.
Accounting of pharmacokinetic parameters when dosing antibacterial agents allows to lower toxic and to repeatedly enhance therapeutic effect of antibiotics, and in some cases and to lower a daily dose. Taking into account pharmacokinetic parameters all antibacterial drugs are divided into concentration and dependent, time - dependent with the minimum post-antibiotic action (PUB) and time - dependent with maximum PUB.
The correlation between a single dose of an antibiotic and its effect, i.e. the more concentration of drug in plasma, the vyrazhenny its effect is characteristic of concentration and dependent drugs. For this group of drugs single introduction of all daily dose, without its division into several receptions is considered rational.
For time - dependent antibiotics the dependence of effect of time during which concentration of drug exceeds minimum overwhelming for a microorganism is characteristic. Therefore when calculating dosing of such drugs, for the purpose of achievement of this effect, recommend to continue after a load dose introduction in the mode of continuous infusion by means of the spray pump. In this case it is necessary to take surely into account time of stability of an antibiotic in solution correctly to calculate a dosing interval.
Time-dependent antibiotics with the expressed post-antibiotic effect represent an intermediate class which effect depends as on time of excess of the minimum overwhelming concentration, and a single dose.
For simplification of dosing of antibiotics and the choice of the correct mode of introduction, it is expedient to carry out medicinal monitoring of concentration of antibacterial drugs in a blood plasma.