内酰胺酶抑制剂抗生素（英文PPT）Lactam.ppt

Miscellaneous Antibiotics Polymyxins Active against gram-negative including pseudomonas. Polymyxin B is only available. Bactericidal inhibits cell wall synthesis. Used only topically . Highly nephrotoxic. Spectinomycin Bactericidal ,inhibits protein synthesis by binding to 30S ribosomal subunits. Active against gram positive gram negative organisms. Rapidly absorbed after intramuscular injection. Excreted through kidney . Clinical uses As an alternative treatment for drug- resistant gonorrhea or gonorrhea in penicillin –allergic patients. No cross-resistance with other drugs used in gonorrhea. A single intramuscular dose is given Adverse effects Pain at the site of injection Fever And nausea Nephrotoxicity ( rare ) Clindamycin Active against gram-positive cocci Gram negative anaerobic organisms Inhibits protein synthesis by binding to 50S ribosomal subunits. Pharmacokinetics Given orally or intravenously Highly bound to plasma proteins Distributes well into all body fluids tissues except brain CSF. Penetrates well into abscess is taken up by phagocytic cells. Metabolized by the liver. Both active drug active metabolites are excreted in bile urine No dosage adjustment is needed for renal failure. Clinical uses Severe anaerobic infections ( bones and joints) . Conjunctivitis. In combination with aminoglycoside or cephalosporin to treat penetrating wounds of the abdomen the gut. Infections in female genital tract ( septic abortion ,pelvis abscess ). For prophylaxis of endocarditis in patients with valvular heart disease Plus primaquine is an effective alternative to co-trimoxazole for moderate or severe pneumocystis jiroveci pneumonia in AIDS patients Adverse Effects Diarrhea , nausea, Skin rash Antibiotic-associated colitis Impaired liver function Neutropenia ( not common ) Vancomycin Bactericidal Inhibits bacterial cell wall synthesis Active on gram-positive bacteria including β-lactamase producer those resistant to methicillin. Ph