β lactam antibiotic
Binds to penicillin binding protein (transpeptidase) and
prevents crosslinking of bacterial peptidoglycan
impairs cell wall synthesis

Inhibitor of bacterial 50S ribosomal subunit

Prevents protein synthesis

Orally not absorbed (need penicillin V)

IV or PO

CSF and bone penetration if inflammation present

Wide distribution including bone but not CSF

60% PB

90% PB

Vd <1L/kg

Inactive metabolite penicollic acid

Hepatic metabolism

90% excreted in urine by tubular secretion
25% unchanged

Biliary. Long post antibiotic effect leads to clostridium overgrowth

GIT– abdominal pain, N/V/D, pseudomembranous colitis, hepatitis
HAEM- agranulocytosis
CNS- confusion, seizure, encephalopathy
HYPERSENSITIVITY- rash, anaphylaxis

- Pseudomembranous colitis due to c.diff
- Contact dermatitis
- Metallic taste
- Anaphylaxis

Narrow-Spectrum
Natural Penicillin

Highly bactericidal, only
gram positives/anaerobes,
susceptible to betalactamases

Targets
GPC: Streptococci, Meningococcus
Listeria (GPB)
GNC: Neisseria, Clostridia
Treponemma (Spiral)

Synergistic effects with
aminoglycosides

Aerobic G+ cocci including MRSA (except enterococci)

Anaerobic G- bacilli

Most aerobic G- bacilli are resistant including pseudomonas (except Capnocytophagia canimorus)

ANTIBIOTIC:
PENICILLIN

ANTIBIOTIC:
LINCOSAMIDE

• Clindamycin is used to treat serious anaerobic and gram positive infection (not enterococcus) and also has MRSA and Plasmodium falciparum cover (but not p. vivax or gram negative aerobes)
• Can be used (along with primaquine) to treat PCP
• Can be used to treat toxin mediated septic syndromes including necrotizing fasciitis and toxic shock syndrome
• MOA: inhibits bacterial synthesis by disrupting the function of 50S ribosomal subunit. Can be bacteriostatic or bacteriocidal depending on concentration and microbe being treated

Narrow spectrum naturally occurring penicillin

Lincosamide

Level 1

Level 3

Resistance
MRSA
Many Staph
-Betalactamase prod
Gram Negatives