Introduction Classification antibiotic penicillin-family (β-lactam) penicillin antipseudomonal penicillins Drugs carbenicillin (oral) ticarcillin (IV) piperacillin (IV) Mechanism Action see Penicillin Resistance penicillinase sensitive most S. aureus are resistant Uses Many Gram-positive, Gram-negative, and anaerobic bacteria Pseudomonas spp. Anaerobes e.g. Bacteroides fragilis Gram-negative rods Combine with other drugs to improve efficacy used with clavulanic acid, tazobactam, sulbactam (penicillinase inhibitors) Adverse effects Allergy