PREBOARD REVIEW POLYPEPTIDES AND UNCLASSIFIED ANTIBIOTICS PDF
Document Details
Uploaded by SimplifiedLoyalty
University of San Agustin - Iloilo City
Tags
Summary
This document is a review of polypeptides and unclassified antibiotics, focusing on lincosamides, clindamycin, vancomycin, and bacitracin. The document details their mechanisms of action, sources, and uses in treating bacterial infections.
Full Transcript
University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department LINCOSAMYCIN They are primarily active against Gram positive bacteria...
University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department LINCOSAMYCIN They are primarily active against Gram positive bacteria, particularly the cocci, but are also effective against non–spore-forming anaerobic bacteria, actinomycetes, mycoplasma, and some species of Plasmodium. Lincomycin binds to the 50S ribosomal subunit to inhibit protein synthesis. University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department LINCOMYCIN University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department CLINDAMYCIN HCL 7(S)-chloro-7- deoxylincomycin (Cleocin) Its activity against streptococci, staphylococci, and pneumococci is indisputably high, and it is one of the most potent agents available against some non–spore-forming anaerobic bacteria, the Bacteroides spp. in particular University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department Clindamycin- (or lincomycin)-associated colitis may be particularly dangerous in elderly or debilitated patients and has caused deaths in such individuals. The colitis, which is usually reversible when the drug is discontinued, is now believed to result from an overgrowth of a clindamycin-resistant strain of the anaerobic intestinal bacterium Clostridium difficile University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department CLINDAMYCIN PALMITATE HYDROCHLORIDE The ester bond is to the 2-hydroxyl group of the lincosamine sugar. The ester serves as a tasteless prodrug form of the antibiotic, which hydrolyzes to clindamycin in the plasma. The salt form confers water solubility to the ester, which is available as granules for reconstitution into an oral solution for pediatric use. University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department CLINDAMYCIN PALMITATE HYDROCHLORIDE Reconstituted solutions of the palmitate hydrochloride are stable for 2 weeks at room temperature. Such solutions should not be refrigerated because thickening occurs that makes the preparation difficult to pour University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department CLINDAMYCIN PHOSPHATE 2-phosphate ester of clindamycin. It exists as a zwitterionic structure that is very soluble in water. It is intended for parenteral (intravenous or intramuscular) administration University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department CLINDAMYCIN PHOSPHATE Solutions of clindamycin phosphate are stable at room temperature for 16 days and for up to 32 days when refrigerated. University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department POLYPEPTIDES BLUE SAMURAI PRODUCTIONS University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department PROBLEMS: Renal toxicity Lacks systemic activity after oral administration SOURCE: Bacillus spp. The antitubercular antibiotics capreomycin and viomycin and the antitumor antibiotics actinomycin and bleomycin are peptides isolated from Streptomyces spp. The glycopeptide antibiotic vancomycin, is isolated from a closely related actinomycete, Amycolatopsis orientalis. University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department VANCOMYCIN HYDROCHLORIDE The isolation of the glycopeptide antibiotic vancomycin (Vancocin, Vancoled) from Streptomyces orientalis It is active against Gram-positive cocci, particularly streptococci, staphylococci, and pneumococci It is not active against Gram-negative bacteria, with the exception of Neisseria spp. University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department It does so by binding with the D-alanine-D-alanine MECHANISM OF terminus of the uridine diphosphate-N- acetylmuramyl peptides required for mucopeptide ACTION polymerization University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department MECHANISM OF The action of vancomycin leads to lysis of the bacterial cell. ACTION University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department BACITRACIN B. Subtilis The organism had been isolated from debrided tissue from a compound fracture in 7-year-old Margaret Tracy, hence the name “bacitracin.” In the dry state, bacitracin is stable, but it rapidly deteriorates in aqueous solutions at room temperature. University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department BACITRACIN Because it is hygroscopic, it must be stored in tight containers, preferably under refrigeration The stability of aqueous solutions of bacitracin is affected by pH and temperature. Slightly acidic or neutral solutions are stable for as long as 1 year if kept at a temperature of 0 to 5°C. University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department BACITRACIN If the pH rises above 9, inactivation occurs very rapidly. pH of a bacitracin solution is best adjusted to 4 to 5 The salts of heavy metals precipitate bacitracin from solution, with resulting inactivation. University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department Polymyxin B sulfate is useful against many Gram negative organisms. POLYMYXIN Its main use in medicine has been in topical applications for local infections in wounds and burns. B1 University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department Polymyxin B sulfate is absorbed poorly from the GI tract; therefore, oral administration is of value only in POLYMYXIN the treatment of intestinal infections such as pseudomonal enteritis or infections caused by Shigella spp. B1 University of San Agustin - Iloilo City College of Pharmacy and Medical Technology - Pharmacy Department