26-11-2012, 01:44 PM
Anti infective agents
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Antibiotics: Definition
Medications used to treat bacterial infections
Ideally, before beginning antibiotic therapy, the suspected areas of infection should be cultured to identify the causative organism and potential antibiotic susceptibilities
Antibiotic Therapy
Empiric therapy: treatment of an infection before specific culture information has been reported or obtained
Prophylactic therapy: treatment with antibiotics to prevent an infection, as in intraabdominal surgery
Therapeutic response
Decrease in specific signs and symptoms of infection are noted (fever, elevated WBC, redness, inflammation, drainage, pain)
Subtherapeutic response
Signs and symptoms of infection do not improve
Actions of Antibiotics
Bactericidal: kill bacteria
Bacteriostatic: inhibit growth of susceptible bacteria, rather than killing them immediately; will eventually lead to bacterial death
Antibiotics: Sulfonamides
One of the first groups of antibiotics
sulfadiazine
Sulfamethoxazole (Bactrim)
sulfisoxazole
Sulfonamides: Indications
Treatment of UTIs caused by susceptible strains of:
Enterobacter spp., Escherichia coli, Klebsiella spp., Proteus mirabilis, Proteus vulgaris, Staphylococcus aureus
Nocardiosis
Pneumocystis carinii pneumonia (PCP)
Upper respiratory tract infections
Other uses
Penicillins: Mechanism of Action
Penicillins enter the bacteria via the cell wall
Inside the cell they bind to penicillin-binding protein
Once bound, normal cell wall synthesis is disrupted
Result: bacteria cells die from cell lysis
Penicillins do not kill other cells in the body