Phthalazole (Phthalazolum)

Phthalazole, like other sulfanilamide preparations, similar in structure to para-aminobenzoic acid (PABA), by the principle of competitive relationships prevents its inclusion in the synthesis of folic acid microbial cells. This leads to a violation of the formation of folic acid, involved in the synthesis of purine and pyrimidine bases, on which the growth and development of microorganisms depends.

The most pronounced bacteriostatic effect of phthalazole is on the vegetative forms of microbes.This effect develops gradually, since in the microbial cell there are some stocks of PABC. In addition, the degree of affinity of Ftalazol with dihydrophosphate acid synthetase - an enzyme limiting the formation of folic acid, in comparison with PABA is much weaker. Therefore, phthalazole must be administered at sufficiently high doses that prevent the use of microorganisms PABA contained in the tissues. Otherwise, resistant strains of pathogens can be formed, which can not be further affected by sulfanilamide preparations.

In addition to antibacterial, Ftalazol, like other sulfonamide preparations, has an anti-inflammatory effect that is associated with its ability to limit the migration of leukocytes, reduce the total number of migrating cell elements and partially stimulate the production of glucocorticosteroids.

The drug acts predominantly in the lumen of the intestine.

The spectrum of antimicrobial action of Ftalazol, like that of other sulfonamides, is narrower than that of antibiotics. Sulfanilamides have a bacteriostatic effect on Streptococcus spp., Pneumococcus spp., Staphylococcus spp.; Meningococcus spp.; Gonococcus, Escherichia coli, Pseudomonas aeruginosa, Shigella dysenteriae, Proteus vulgaris.