This document provides a summary of penicillin and other beta-lactam antibiotics. It classifies beta-lactams as very narrow, narrow, wide, or extended spectrum based on their antimicrobial activity. It describes the mechanisms of action, resistance, pharmacokinetics, clinical uses, and adverse effects of different beta-lactam classes including penicillin, extended spectrum penicillin, anti-pseudomonal penicillin, carbapenems, and monobactams. The document is intended to educate medical students on the properties and uses of various beta-lactam antibiotics.

1. Fazly Fathima Shimlah
MBBS
3rd Year
Pharmacology

5. CLASSIFICATION
1.VERY NARROW SPECTRUM
​(ANTI STAPHYLOCOCCAL , BETA LACTAMASE RESISTANT)
Methicillin ,Nafcillin, Oxacillin, Dicloxacillin
2.NARROW SPECTRUM ​(NATURAL)
Penicillin G , Penicillin V
3.WIDE SPECTRUM
Ampicillin , Amoxycillin
4.EXTENDED SPECTRUM​ (ANTI PSEUDOMONAL)
Carbenicillin*, Ticarcillin*, Piperacillin

6. BETA LACTAMASE INIBITORS
• Sulbactam
• Tazobactam
• Clavulanic acid

7. MECHANISM OF ACTION
1.Inhibition of cell wall synthesis
-Binding to Penicillin Binding Protein(PBP)
-Inactivating Transpeptidase
2.Degradation of existing cell wall
-Autolysins

8. RESISTANCE
1. Beta Lactamase/Penicillinase
2.Modification of PBP
3.Cell membrane impermeability
4.Efflux pumps

11. PHARMACOKINETICS
• Administered 1-2 hours before or after meals
• Route of Administration- It depend on the stability of the drug to
gastric acid and severity of infection.
E.g. Oral -Penicillin V , Dicloxacillin
I/V or I/M - Piperacillin with Tazobactam
• Useless against intracellular bacteria
• Excreted by kidney and breast milk and Anti-Staphylococcal other
than Methicillin are excreted by biliary route
• Half Life- Penicillin has a short half-life 30min
Ampicillin and other extended Penicillin 1-2hr

12. •Crosses the placental barrier but not teratogenic​
•Penicillin shows
-Synergism with Aminoglycosides and Fluoroquinolones
-Antagonism with Tetracyclines​

13. CLINICAL USES
Penicillin G​
•Gram positive cocci e.g. Streptococci
•Gram negative cocci e.g. N.Gonorrhea
•Gram positive rods e.g. Bacillus anthracis
•Actinomycetes
•Spirochetes e.g. Treponema pallidum
•Gram negative anaerobe
Penicillin V
•Used only for minor infections due to low bioavailability

14. Extended Spectrum Penicillin
•Similar to penicillin G
•For gram positive cocci , gram negative cocci ,gram positive rods
, actinomycetes and gram negative anaerobic
•And also gram negative bacilli , typhoid and shigellosis
•Prophylactically used by dentists for having abnormal heart
valves

15. •Anti-Staphylococcal
•For Streptococcus and Staphylococcus​
Anti-Pseudomonal
• For many gram negative organisms

16. ADVERSE EFFECTS
• Allergy- Anaphylactic Shock
Serum sickness type reaction
Maculopapular rashes
Angioedema
• Renal- Interstitial nephritis
• GIT- Nausea, diarrhea, vomiting, pseudomembranous colitis
• Blood- hemolytic anemia, eosinophilia ,neutropenia
• Liver- hepatitis

17. CARBAPENEM
• Synthetic compound
• Combination imipenem and Cilstatin
• Broad spectrum and sensitive only to metalobeta Lactamase
• Clinical Uses
• Administered via I/V
• Excreted through kidney
Adverse Effects
•Skin rashes , eosinophilia,Neutroenia,Nausea , vomiting ,diarrhea
•At high doses- epilepsy, confusion, encephalopathy
Clinical Uses
• Act against – Gram positive cocci, gram negative
rods,anaerobes,Pseudomonas aeroginosa

18. MONOBACTAM
• Aztreonam is the only member of this group
• Narrow spectrum
• Resistant to all beta Lactamases
• Clinical Uses
• Administered via I/V , I/M
• Excreted through kidney
Adverse Effects
•Skin rashes , phlebitis, abnormal liver functioning,
vertigo,headache​
Clinical Uses
• Act against – Gram negative bacteria and Enterococci

19. References
• Lippincott's Illustrated Reviews: Pharmacology 5th edition
• Basic & Clinical Pharmacology, 14e. Bertram G. Katzung

20. Thank You