antibiotics Flashcards
Penicillin G, V
bind PBPs (transpeptidases) preventing them from cross-linking peptidoglycan
Indications S. pneumo S. pyogenes Actinomyces N. Meningitidis T. pallidum
Toxicity
- hypersensivitiy
- hemolytic anemia
V is oral
P is parenteral
Methicillin
Nafcillin
Oxacillin
penicillinase-resistant penicillins
- **anti-staphylococcal
- bind PBP–> prevent cross-linking of peptidoglycan
Toxicity
- type IV hypersensitivity reaction
- interstitial nephritis (methicillin)
***Nafcillin crosses BBB
Ampicillin
Amoxicillin
broad spectrum penicillins
-bind PBP—>prevent cross-linking of peptidoglycan
Indications:
HELPS ME
H. influenza E. coli Listeria Proteus S. pyogenes Moraxella catarrhalis Enterococcus faecalis
Toxicity
-hypersensitivity reaction
-non allergic rash
pseudomembranous colitis
- amoxacillin has better oral availability
- ampicillin IV
Ticarcillin + Clavulanic Acid
anti-pseudomonal Penicillin
-binds PBP + beta-lactam inhibitor
Indications:
- pseudomonas
- gram negative rods
- nosocomial infections
- used in combination with:
- aminoglycosides
- fluoroquinolones
- vanco
Toxicity
- hypersensitivity rxn
- hypernatremia (arrhythmias)
- increase bleeding time
Piperacillin + Tazobactam
anti-pseudomonal Penicillin
-binds PBP + beta-lactam inhibitor
Indications:
- pseudomonas
- gram negative rods
- nosocomial infections
- used in combination with:
- aminoglycosides
- fluoroquinolones
- vanco
Toxicity
- hypersensitivity rxn
- hypernatremia (arrhythmias)
- increase bleeding time
*Big Gun
Aztreonam
Monobactam
-resistant to B-lactamase
Indications:
- gram (-) infections in those with history of penicillin allergy
- MDR pseudomonas
Used in combination with ahminoglycosides
Imipenem + cilastatin
Carbapenem
-resistant to beta lactamases
**Wide Spectrum** gram (+) cocci gram (-) rods Neisseria anaerobes (B. fragilis)
- significant side effects (seizures), so only use for life threatening infections when other drugs have failed
- cilastin blocks renal inactivation of imipenem
Ciprofloxacin
Moxafloxacin
Levofloxacin
fluoroquinolone
MOA
-inhibits bacterial DNA gyrase and topoisomerase IV
Indications:
*gram (-) only!
GI/UTI infections
-E.coli
-klebsiella
-salmonella
-shigella
-campylobacter
Legionella
mycoplasma
mycobacterium
chlamydiae
Toxicity:
- damage to growing cartilage
- contraindicated in patients less than 18 yo or pregnant
-QT prolongation—> Tosade de pointes
Gentamycin
aminoglycoside
O2 dependent transport into bacteria
-cell wall synthesis inhibitors increases drug permeability
-low pH decreases uptake of drug
***not good for anaerobes/abscesses!
MOA
Dose dependent bacteriCIDAL agents
-Irreversibly bind 30s ribosomal subunit
⬇
block initiation of protein synthesis
-Disassociate 50s and 30s
-misreading of mRna
Indications:
- enterococcal endocarditis
- serious gram (-) infections
Toxicity:
- *ototoxicity: irreversible loss of vestibular function; tinnitus
- reversible nephrotoxicity
Tobramycin
aminoglycoside
O2 dependent transport into bacteria
-cell wall synthesis inhibitors increases drug permeability
-low pH decreases uptake of drug
***not good for anaerobes/abscesses!
MOA
Dose dependent bacteriCIDAL agents
-Irreversibly bind 30s ribosomal subunit
⬇
block initiation of protein synthesis
-Disassociate 50s and 30s
-misreading of mRna
Indications:
-inhaled for cystic fibrosis pseudomonas infection
Toxicity:
- *ototoxicity: irreversible loss of vestibular function; tinnitus
- reversible nephrotoxicity
Amikacin
aminoglycoside
O2 dependent transport into bacteria
-cell wall synthesis inhibitors increases drug permeability
-low pH decreases uptake of drug
***not good for anaerobes/abscesses!
MOA
Dose dependent bacteriCIDAL agents
-Irreversibly bind 30s ribosomal subunit
⬇
block initiation of protein synthesis
-Disassociate 50s and 30s
-misreading of mRna
Indication
-TB
Toxicity:
- *ototoxicity: irreversible loss of vestibular function; tinnitus
- reversible nephrotoxicity
Streptomycin
aminoglycoside
O2 dependent transport into bacteria
-cell wall synthesis inhibitors increases drug permeability
-low pH decreases uptake of drug
***not good for anaerobes/abscesses!
MOA
Dose dependent bacteriCIDAL agents
-Irreversibly bind 30s ribosomal subunit
⬇
block initiation of protein synthesis
-Disassociate 50s and 30s
-misreading of mRna
Indication:
- TB
- 2nd line tx for endocarditis
Toxicity:
- *ototoxicity: irreversible loss of vestibular function; tinnitus
- reversible nephrotoxicity
Neomycin
aminoglycoside
O2 dependent transport into bacteria
-cell wall synthesis inhibitors increases drug permeability
-low pH decreases uptake of drug
***not good for anaerobes/abscesses!
MOA
Dose dependent bacteriCIDAL agents
-Irreversibly bind 30s ribosomal subunit
⬇
block initiation of protein synthesis
-Disassociate 50s and 30s
-misreading of mRna
Indication
-bowel surgery
Toxicity:
- *ototoxicity: irreversible loss of vestibular function; tinnitus
- reversible nephrotoxicity
TMP-SMX
sulfonamide
inhibit sequential steps in folate synthesis
SMX inhibits dihydropteroate
TMP inhibits dihydrofolate reductase (not a sulfa drug)
Indications:
- UTI treatment and prophylaxis
- C. trachomatis
SMX Toxicity
- SJS (hypersensivity rxn)
- tubulointerstitial nephritis
TMP toxicity
megaloblastic anemia
leukopenia
granulocytopenia
TMP-Treats Marrow Poorly
Tetracycline
Doxycycline
Minocycline
Tigecycline
Tetracyclines (bacteriostatic)
MOA
-binds 30s ribosome–> prevents attachment of charged aminoacyl tRNA
Indications
- Borrelia burgdorferi (Lyme)
- mycoplasma pneumonia
- Rickettsia
- Acne (P. acnes)
- H. pylori
*Tigecycline can be used for MRSA
Toxicity
- discoloration of teeth
- impaired bone growth
- photosensitivity
-avoid in children and pregnancy
