Pharmacology Antibiotics Flashcards
Opportunistic Pathogens
Organisms that do not normally produce disease
- Malnutrition, immunodeficiency, antibiotic treatment
- Staphylococcus aureus, E. coli, candida
Circle shaped bacteria
(Coccus)
Ex: streptococcus, staphylcoccus
Rod shaped bacteria
(bacillus)
Ex: escherichia, balicus
Spiral shaped bacteria
(spirillum)
Ex: leptospira, spirillum
Gram-Negative
do not retain the gram stain
- thin cell wall surrounded by an outer lipopolysaccharide membrane
- Examples:
- E. coli, gonorrhoeae, pseudomonas, pneumoniae, proteus mirabilis
Gram-Positive
retain gram stain
- thicker cell wall
- Example:
- bacillus anthracis, Staph, Strep, C. diff
Two names for a cell wall
peptidoglycan or murein
Chemotherapeutic agents
antibacterial, antifungal, antiparasitic, antiviral, antineoplastic
- Inhibition of cell wall synthesis
- penicillins, cephalosporins, bacitracin, and vancomycin
- Inhibition of protein synthesis
- chloramphenicol, erythromycin, tetracyclines, and streptomycin
- Inhibition of Nucleic acid Replication
- Quinolones, Rifampin
- Injury to plasma membrane
- polymyxin B
- Inhibition of synthesis of essential metabolites
- sulfanilamide, trimethoprim
Which chemotherapy agents are most and least toxic?
least: antibacterials
most: antineoplastics
Bacteriostatic
agents that inhibit the growth of bacteria
bactericidal
agents that kill bacteria
Pseudomembranous Colitis
associated with Clostridium difficile overgrowth
(C. diff)
Vaginal yeast infection
Candida albicans overgrowth
Cell Wall Synthesis Inhibitors
- B-lactam
- penicillins
- cephalosporins
- Polypeptides
- vancomycin
- bacitracin
B-Lactam Antibiotics
covalently and irreversibly inhibit Penicilin Binding Proteins (PBPs)
PBPs are enzymes that catalyze the crosslinking of the peptidoglycan cell wall
- Transpeptidases
- Carboxypeptidases
- Endopeptidases
Resistance to B-Lactam Antibiotics
- Inactivation by B-lactamase
- modification of penicillin binding proteins
- impaired penetration of drug
- effux of drug
- gram-negative bacteria may synthesize an efflux pump that transports B-lactams
B-Lactamase Inhibitors
Clavulanic acid, sulbactam, tazobactam
Penicillin G
- narrow spectrum
- high activity against gram-positive bacteria
Ampicillin
- extended spectrum
- high activity against gram positive
- greater activity against gram-negative
- Associated with pseduomembranous colitis
Unasyn
Ampicillin + Sulbactam
Nafcillin
- high activity against gram-positive
- resistant to B-lactamases
- may cause Neutropenia