Antibiotics Flashcards
Beta Lactam Members
Penicillin Ampicillin Amoxicilin Ticarcillin Cephalosporins Sublactams Carbapenems (Imipenem) Monobactams (Aztreonam)
Beta Lactam Mechanism of Action
Distrupt Cell wall synthesis (peptidoglycan synthesis)
Stimulate autolysins which degrade peptidoglycan
Some Gram negative and some gram positive
Excretion through kidneys
Beta Lactam resistance mechanism
Beta lactamase (enzyme which cleaves Beta Lactam ring) production
Extended spectrum Beta lactamase
Alteration in penicillin binding proteins
*Do not mix aminoglycoside with penicillin in the same syringe
Beta Lactam Antagonism/adverse effects
Antagonism: Tetracycline and chloramphenicol
Adverse effects:
Penicillin allergy (can act as hasten)
Type 1 hypersensitivity
Tetracycline Spectrum/Action
Broad spectrum
Inhibit protein synthesis (bind to 30s ribosome)
Bacteriostatic
Time dependent antimicrobials
Members of Tetracycine
Oxytetracycline
Chlortetracycline
Doxycycline
Minocycline
Tetracyclines
Resistance mechanism
Energy dependent efflux
Ribosomal protection
Chemical modification and catalysis by enzymes
Tetracyclines
Notable facts
Cheating agents
Cross placental barrier
Secreted in milk
Anti-inflammatory, neuroprotective and immunomodulant effects
Tetracyclines
Toxicity and adverse effects
Irritant
Cardiovascular effects
Tooth discoloration
Alteration of intestinal flora and enters Olivia (horses)
IV adm of doxy in horses may result in cardiovascular collapse
Nephrotoxicity
Aminoglycoside
The Fam
Gentamicin Amikacin Tobramycin Streptomycin Kanamycin Neomycin Spectinomycin
Aminoglycosides
Mech of Action
Inhibit protein synthesis (30s ribosome) Bactericidall Concentration dependent antimicrobial activity Oxygen dependent uptake by the microbes and purple to debris inactivate aminoglycosides (not for anaerobic infections) Prolonged post antibiotic effect Need parenteral adm Does not penetrate BBB Renal excretion
Fluoroquinolones
The Fam
Enrofloxacin
Ciprofloxacin
Fluoroquinolones
Mech of Action
Inhibit DNA gyrase (topoisomerase II) and therefore replication
Bactericidal
High potency against Gram neg and moderate potency against gram positive
Synergism with beta lactams and aminoglycosides
Macrolides
(Azalides, ketolides)
Family
Erythromycin, Azithromycin, Clarithromycin (Tulathromycin, Tilmicosin, Tylosin)
Macrolides (mode of action)
Intracellular accumulation in phagocytes
Inhibit protein synthesis (50s ribosome subunit)
Bacteriostatic
