Cephalosporins 4 generations in tablets. Antibiotics-cephalosporins 4 generations

Cephalosporins are referred to as beta-lactam drugs. They represent one of the largest classes of antibacterial medicines.

General information

Relatively new are considered cephalosporins 4 generations. Oral forms in this group are absent. The remaining three are provided for oral and parenteral administration. Cephalosporins have high efficacy and relatively low toxicity. Due to this, they occupy one of the leading positions in the frequency of use in clinical practice of all antibacterial agents.

Indications for use for each generation of cephalosporins depend on their pharmacokinetic properties and antibacterial activity. Medicines have a structural similarity with penicillins. This predetermines a single mechanism of antimicrobial action, as well as cross-allergy in a number of patients.

Activity spectrum

Cephalosporins have a bactericidal effect. It is associated with a violation of the formation of bacterial cell walls. In the series from the first to the third generation, there is a tendency to significantly expand the spectrum of activity and increase antimicrobial activity on gram-negative microbes with a slight decrease in the effect on gram-positive microorganisms. The common property for all agents is the absence of a significant effect on enterococci and some other microbes.

Many patients are interested in why are not produced cephalosporins 4 generations in tablets? The fact is that these medicines have a special molecular structure. This does not allow the active components to penetrate into the structures of the cells of the intestinal mucosa. Therefore, cephalosporins 4 generations in tablets are not produced. All medicines of this group are intended for parenteral administration. Cephalosporins of 4 generations are produced in ampoules with a solvent.

Cephalosporins 4 generations

Preparations of this group are appointed exclusively by specialists. This is a relatively new category of medicines. Cephalosporins 3, 4 generations have a similar spectrum of effects. The difference is in fewer side effects in the second group. The "Tsefepim" remedy, for example, is close to third-generation medicines in a number of parameters. But due to some features in the chemical structure, it has the ability to penetrate through the outer wall of gram-negative microorganisms. In this case, the agent "Cefepime" is relatively stable to hydrolysis by beta-lactamases (chromosomal) C-class. Therefore, in addition to the characteristics inherent in cephalosporins of 3 generations ("Ceftriaxone", "Cefotaxime"), the drug exhibits such features as:

• Influence on microbes-hyper-producers of beta-lactamases (chromosome) C-class;
• High activity with respect to non-fermenting microorganisms;
• Higher resistance to hydrolysis of beta-lactamases with extended spectrum (the significance of this feature is not completely clear).

Inhibitor-protected medications

This group includes one drug "Cefoperazone / Sulbactam". In comparison with the mono-drug, the combination medicine has an extended spectrum of activity. It has an effect on anaerobic microorganisms, most strains of enterobacteria capable of producing beta-lactamases.

Pharmacokinetics

Parenteral cephalosporins 3, 4 generations are very well absorbed when injected into the muscle. Medications for oral administration are characterized by a high absorption in the digestive tract. Bioavailability will depend on the specific medicament. It ranges from 40-50% (for the drug "Cefixim", for example) to 95% (for Cefaclor, "Cefadroxil", "Cephalexin"). Absorption of certain oral medications may be slowed by eating. But such a drug as "Cefuroxime ascetil" during the absorption is subjected to hydrolysis. The faster release of the active ingredient is facilitated by food.

Cephalosporins of 4 generations are well distributed among many tissues and organs (except the prostate), as well as secrets. In high concentrations, medications are found in peritoneal and synovial, pericardial and pleural fluids, bones and skin, soft tissues, liver, muscles, kidneys and lungs. The ability to pass BBB and form therapeutic concentrations in the CSF is more pronounced in third-generation drugs such as Ceftazidime, Ceftriaxone, and Cefotaxime, and the representative of the fourth, Cefepim.

Metabolism and excretion

Most of the cephalosporins do not undergo disintegration. An exception is the medicine "Cefotaxime". It is biotransfomiruetsya with the subsequent formation of the active product. Excreted cephalosporins of the 4th generation, as well as representatives of the rest, kidneys predominantly. When excreted in urine, very high concentrations are found.

Medications "Cefoperazone" and "Ceftriaxone" are distinguished by a double route of excretion - liver and kidneys. For most cephalosporins, the elimination half-life is within one to two hours. A longer time is required for "Ceftibuten", "Cefixim" (3-4 hours), and "Ceftriaxone" (up to 8.5 hours). This makes it possible to appoint them once a day. Against the background of renal failure, the dosage of medication requires adjustment.

Side effects

Antibiotics - cephalosporins of 4 generations - cause a number of negative consequences, in particular:

• Allergies. Patients may have multiform erythema, rash, hives, serum sickness, eosinophilia. Side effects of this category include anaphylactic shock and fever, angioedema, bronchospasm.
• Hematologic reactions. Among them is a positive Coombs test, leukopenia, eosinophilia (rarely), hemolytic anemia, neutropenia.
• Nervous disorders. When using higher doses in patients with renal dysfunction, convulsions are noted.
• From the liver: increased activity of transaminases.
• Digestive disorders. Among the negative consequences are quite common diarrhea, pseudomembranous colitis, vomiting and nausea, tenderness in the abdomen. In the case of a liquid stool with fragments of blood, the drug is canceled.
• Local reactions. These include infiltration and soreness in the intramuscular injection site and phlebitis with intravenous injection.
• Other consequences are expressed in the form of candidiasis of the vagina and mouth.

Indications and contraindications

Cephalosporins of 4 generations are prescribed for severe, low-predominantly infections caused by multiresistant microflora. These include pleural empyema, abscess in the lung, pneumonia, sepsis, joint and bone lesions. Cephalosporins 4 generations are indicated for infections of a complicated type in the urinary tract, against neutropenia and other immunodeficient conditions. Medication is not prescribed for individual intolerance.

Precautionary measures

In use, a cross-type allergy is noted. In patients with intolerance to penicillins, a similar reaction to cephalosporins of the first generation is noted. Cross-allergy in the application of the second-third category is less common (in 1-3% of cases). If there are immediate reactions in the anamnesis (for example, anaphylactic shock or urticaria), first-generation drugs should be administered with caution. Preparations of the following categories (in particular, the fourth) are safer.

Lactation and pregnancy

Cephalosporins are prescribed in the prenatal period without special restrictions. However, adequate controlled drug safety studies were not conducted. In low concentrations, cephalosporins can penetrate into the milk. Against the background of the use of medicines during lactation, changes in the intestinal microflora, candidiasis, rashes on the skin, sensitization of the child are likely.

Pediatrics and geriatrics

When used in neonates, it is likely that the half-life will increase on a background of delayed renal excretion. In elderly patients there is a change in renal function, in connection with which, probably slowing the withdrawal of medications. This may require adjustment of the dosage regimen and dosage.

Kidney Dysfunction

Since the excretion of most cephalosporins occurs through the kidneys mainly in the active form, the dosage regimen should be adjusted taking into account the characteristics of the organism. When high doses are used, especially in combination with loop diuretics or aminoglycosides, a nephrotoxic effect is likely.

Liver dysfunction

Some drugs are excreted in the bile, so for patients with severe liver diseases the dosage should be reduced. In such patients there is a high predisposition to bleeding and hypoprothrombinemia with the use of "Cefoperazone". For preventive purposes, vitamin K is recommended.