1. Copyright (c) 2004 Elsevier Inc. All rights reserved. Drugs That Weaken the Bacterial Cell Wall I: Penicillins Chapter 80

2. Copyright (c) 2004 Elsevier Inc. All rights reserved. Drugs That Weaken the Bacterial Cell Wall: Penicillins Penicillins –Weaken the cell wall, causing bacteria to take up excessive water and rupture –Bactericidal –Bacterial resistance Inability of penicillins to reach their target Inactivation of penicillins by bacterial enzymes

3. Copyright (c) 2004 Elsevier Inc. All rights reserved. Classification of Penicillins Penicillins Narrow spectrum –Pencillinase sensitive Narrow spectrum –Pencillinase resistant Broad spectrum Extended spectrum

4. Copyright (c) 2004 Elsevier Inc. All rights reserved. Penicillin G (Benzylpenicillin) Four forms –Sodium penicillin –Potassium penicillin –Procaine penicillin –Benzathine penicillin Adverse effects –Allergy—penicillins are the most common cause of drug allergy

5. Copyright (c) 2004 Elsevier Inc. All rights reserved. Penicillin Allergy Types –Immediate (2 to 30 minutes) –Accelerated (1 to 72 hours) –Late (days or weeks) Anaphylaxis – Laryngeal edema – Bronchoconstriction – Severe hypotension

6. Copyright (c) 2004 Elsevier Inc. All rights reserved. Penicillin Allergy (cont.) Treatment –Epinephrine –Respiratory support –Prevention—skin testing

7. Copyright (c) 2004 Elsevier Inc. All rights reserved. Penicillinase-Resistant Penicillins Four agents –Nafcillin –Oxacillin –Cloxacillin –Dicloxacillin

8. Copyright (c) 2004 Elsevier Inc. All rights reserved. Broad Spectrum Penicillins (Aminopenicillins) The aminopenicillins consist of three agents –Ampicillin –Amoxicillin –Bacampicillin Adverse effects –Rash –Diarrhea

9. Copyright (c) 2004 Elsevier Inc. All rights reserved. Extended Spectrum Penicillins (Antipseudomonal Penicillins) The extended spectrum penicillins consist of four agents –Ticarcillin –Carbenicillin indanyl –Mezlocillin –Piperacillin