口腔颌面外科抗生素的应用（英文ppt）antibioticsin oral and maxillofacial

Antibiotics In Oral and Maxillofacial Surgery Ziad Malkawi DDS, MSc, Max.Fac.s.Cert., FFDRCSI Oral and Maxillofacial Surgery Faculty of Dentistry University of Jordan Definitions n Antimicrobial agents: Any Inhibitor of microbial growth. n Antibiotc agents: Strictly naturally produced inhibitor of microbial growth. n Semi synthetic antibiotic: Agent derived by modification of a natural antibiotic. The Ideal Antibiotic n Should have maximal toxicity for the pathogen whilst causing the minimum damage to the host tissue. This is whats called: ( Selective Toxicity ) Antibiotics nConsider: nRoute. nAbsorption. nExcretion. nBacterio-static or bacterio-cidal. nWay of action. nCost. Antibiotic and Human host n Consider: n Allergy. n Age and weight of the patient. n Medical problems: n Liver failure. n Renal failure. n Immuno-suppressed patient. n Gastro intestinal tract diseases. n Pregnancy: n Amoxycillin, Cephalosporin, Gentamicin. Antibiotic and Micro-organism / Infection n Consider: n Severity of infection. n Type of organism: n G +ve or G ve bacteria. n Aerobic or an aerobic or mixed bacteria. n Resistance. n Site of infection: n Brain, soft tissue, bone, Sinuses, kidney etc. n State of patient: n Septic, pyretic, dehydrated etc. Selective toxicity is best achieved where an antimicrobial agent blocks a metabolic pathway n Suitable targets Includes: n Bacterial cell wall synthesis. n Bacterial protein synthesis. n Folic acid synthesis. n Nucleic acid metabolism. n Membrane disorganizing agents. 1) Antibiotic which inhibit cell wall synthesis 1. Beta lactams: Penicillins: mainly against G +ve bacteria Cephalosporin: 1st generation Cephroxine. 2nd generation cephrorixime. 3rd generation cephrotaxine: can cross BBB Mono - lactams. Carbapenems. Augmentin: Amoxycillin +Glavulanic acid Amoxycillin: Against aerobic and anaerobic bacteria. Antibiotic which inhibit cell wall synthesis 2. Antibiotics which inhibit peptidoglycan synthesis: n Cycloserine. n Phosphonomycin ( Fosfonomycin ). n Bacitracin. n Vancomycin. n Teichoplanin. 2) Antibiotic which inhibit protein synthesis n Aminoglycoside: (All are bacteriocidal except Spectinomycin) n Gentamicin: against G ve n Cant cross BBB. n Cant cross puss. n Good for septecaemia and bacteraemia. n Tetracyclin: Doxycyclin, Oxytetracyclin. n Chloramphenicol. n Erythromycin Clarythromycin. n Lincomycin and Clindamycin. n Fusidic acid. 3) Antifolate agents nSulphonamide: nCan cause bone marrow suppression nExcellent for G +ve and G -ve bacteria. nExcellent for meningitis as it can cross BBB. nTrimethoprim. 4) Drugs affecting nucleic acid metabolism n Quinolones: such as Ciprofloxacin. n Novobiocin: Mainly in laboratory work. n Refampicin: Very active against G +ve and mycobacteria. n Nitromidazole: Toxic for anaeribic bacteria only, e.g. metronidazole. n Nitrofurans: Mainly for the treatment of UTI. n Septrin: Excelent for Pneumcystis (HIV patients). 5) Membrane disorganizing agents nPolymyxins: G ve bacteria. nPolyenes: Too toxic for clinical use: nEfficient as antifungal agents: nAmphotericin B. nNystatin. Dental infections n Most important is drainage of pus. n If antibiotics are given early enough in the course of infection may abort the process and prevent pus formation. n Most oral infection are mixed in origin. n i.e. G-ve, G+ve, aerobic and anaerobic bacteria. n The vast majority of organism infecting the mouth are sensitive to penicillin. n Loading dose: Double the usual dose will achieve the therapeutic blood level rapidly. Alternatives to peniciilin n Erythromycin: n Gastric intolerance. n Rapid organism resistance. n Azithromycin and Clarythromycin are better and less side effect. n Teracycline: mainly in periodontal disease. n Cephalosporin: cross sensitivity with penicillin 3 10%. n Clindamycin: Pseudomemranous colitis. Consider Prescribing Antibiotics n In the presence of painful swelling. n Trismus: if the other causes excluded. n In the presence of pus like discharge. n Symptoms which become worst after 36 hours after surgery. n Pyrexia and tachycardia: Temp38C, Pulse 100 Consider children and older patients. G ve dont always cause pyrexia. n If no response within 72 hours: n Change antibiotic and check the type of organism. n If staphylococcus suspected, give Flucloxacillin. Consider Hospitalization of the patient if n The patient is dehydrated and toxic. n There is impending airway compromise. n In orbital infection or very close to the orbit: Cavernous sinus thrombosis. n Pyrexia is sustained above 39C. In the Hospital Consider n Hematolical investigation: n WBC, Hematocrit and ESR. n Radigraph and CT scan especially if there is airway endanger. n Drainage may be required and take cultural swab. n Consider multiple antibiotic therapy. n If pyrexia persist , blood should be cultured. n Patient usually dehydrated: consider IV antibiotic and IV fluid. Cont. In the Hospital Consider n Consider broad spectrum antibiotics: n Like 3rd generation of Cephalosporin such as Cephataxime and metronidazole. n Once the culture result known give the antibiotic for specific organism. n Soft tissue infection usually take 1-2 weeks. n Osteomylitis and actinomycosis required 4 6weeks. n Antibiotic should be given until there is no further discharge, temperature is normal and any swelling is oedemetous only. Analgesia in general dental practice n NSAIDs: n Aspirin. n Ibubrofen. n Mefenamic Acid ( Ponstan ). n Diflunisal. n Codeine phosphate. n Pentazocine. n Buprenorphine n Pethidine ( Meperidine ) Analgesia in general dental practice n Non NSAIDs: n Parcet