B3.022 - Antimicrobial Drugs Flashcards
What are the groups of ICWS
Penicillins
Cephalosporins
Beta Lactams
Others
What are the types of penicillins
Penicillins
Extended spectrum
Anti Staph
Anti Pseudomonal
What are the Extended spectrum penicillins
Ampicillin
Amoxacillin
What are the Anti Staph Penecillins
Methicillin
Nafcillin
Oxacillin
What are the Anti Pseudomonal drugs
Ticarcillin
Piperacillin
What are the 1st generation cephalosporins
Cephalexin
Cefazolin
What are the 2nd generation cephalosporins
Cefuroxime
Cefotetan
Cefaclor
What are the 3rd generation cephalosporins
Cefotaxime
Ceftriaxone
Ceftazidime
What are the 4th generation cephalosporin drugs
Cefepime
What are the other beta lactams
Aztreonam Imipenam Meropenam Clavulanic Acid Tazobactam
What are the other cell wall synthesis inhibitors
Vancomycin
Bacitracin
Fosfomycin
What are the agents that affect cell membranes
Polymixin B and E
What are the types of protein synthesis inhibitors
- Tetracyclines
- Macrolides
- Aminoglycosides
- Others
What are the tetracyclines
Tetracycline
Doxycycline
Tigecycline
What are the macrolides
Erythromycin
Clarithromycin
Azithromycin
Telithromycin
What are the aminoglycosides
Gentamicin
Streptomycin
Tobramycin
Neomycin
What are the other IPSs
Chloramphenicol
Clindamycin
Streptogramins
Oxazolidinones
What are the types of inhibitors of folate dependent pathways
- Sulfonamides
2. Dihydrofolate reductase inhibitors
What are the sulfonamides
Sulfamethoxazole
Sulfasalazine
Silver sulfadiazine
Co-trimoxazole
What are the DNA gyrase inhibitors
Ciprofloxacin
Levofloxacin
What are the UT antiseptics
Nitrofurantoin
Systemic agents
What are the first line anti-mycobacterial drugs
Isoniazid Ethambutol Rifampin Streptomycin Pyrazinamide
What are the second line anti-mycobacterial drugs
Cycloserine
Ethionamide
Capreomycin
PAS
Describe penicillin toxicity
Ver selective, bacteriocidal in growing and proliferating cells
What is the MOA of penicillins
Covalent binding to transpeptidases/PBPs
Inhibition of cross linking of cell wall
Activation of murein hydrolases (autolysins)
Describe the absorption of penicillins
Oral even though they’re acid sensitive
IV, IM
Depot preparation of penicillin G
Describe the distribution of penicillins
Good to most tissues except eye, prostate and CNS
How are penicillins excreted
Tubular secretion
What can block tubular secretion of penicillins
Probenecid
Which penicillin isn’t excreted tubularly
Nafcillin its excreted by bile
What is the half life of penicillins
1 hour
Do penicillins exhibit time dependent or concentration dependent killing
Time dependent
What are the clinical uses of Pen G and Pen V
Primarily gram + bacteria
What which penicillin class is beta lactamase resistant
Anti staph - nafcillin, methicillin, oxacillin
What are the extended spectrum penicillins used for clinically
Gram + and some Gram -
What are the anti pseudomonal penicillins used for
Proteus sp. and pseudomonas
What is the issue with using antipsudomonal penicillins and what do you have to combine them with
They develop resistance rapidly, combine with aminoglycocides or fluoroquinolones
When should antipseudomonals be used
Only when absolutely indicated to protect their therapeutic value
What are the most common adverse reactions of penicillins
Ampicillin rash
Hypersensitivity
What is resistance to penicillins due to
No cell wall No activation of autopsies (murein hydrolases) Metabolically inactive Inaccessible PBPs Beta lactamase production
What can you do to prevent resistance due to beta lactamase
Give a beta lactamase inhibitor
Clavulanic acid
Sulbactam
Tazobactam
What are issues associated with overuse of penicillins
Resistance
Sensitization
Superinfections be resistant organisms
What are cephalosporins used for
In penicillins won’t work, less sensitive to beta lactamase
Broader spectrum of activity
What is a negative about using cephalosporins instead of penicillins
Renal toxicity is more common
Poor oral absorption
Some cross reactivity with penicillins
As the generation of cephalosporins goes up so does
Greater gram - activity Less beta lactamase activity Cephalosporinase resistant Less toxic to patient Better distribution especially to CNS
What are adverse effects of cephalosporins
Renal toxicity, enhanced by aminoglycosides
Disulfiram effect; bleeding and platelet disorders
Hypersensitivity
What is aztreonam used for
Gram - aerobes
How do azteronam and Imipenem respond to beta lactamase
They are resistant
Do aztreonam and imipenem cross the blood brain barrier?
Yes
What is imipenem used for
Broad spectrum gram + and gram -, anaerobes
What should imipenem be used with if treating pseudomonas
Aminoglycosides
How is imipenem administered
IV only
How is imipenem inactivated and how do you prevent that
Renal dipeptidase, co administer with cilastatin
What is meropenem
Dipeptidase resistant carbapenem (as opposed to imipenem)
How does vancomycin work
Inhibits transglycoslylation (step right before transpeptidation)
What is vancomycin used for
Bacteriocidal for gram +
How is vancomycin administered and for what
Orally for C. Diff
IV for systemic infections
What is vancomycin synergistic with when treating MRSA
Aminoglycosides
How is vancomycin cleared from IV administration
Through the kidneys - enhances oto and renal toxicity of aminoglycosides
What is an adverse effect of vancomycin caused by histamine release and how is it avoided
Red man or red neck syndrome, administer slowly or with antihistamines
What is something negative that developed because of vancomycin overuse
Vancomycin depended enterococci
What is fosfomycin used for
Gram + and gram -
What is fosfomycins MOA
inhibits cytoplasmic step in cell wall precursor synthesis
How is fosfomycin taken up
Using G6P transporter
How is fosfomycin taken, excreted and what type of infection is it used for
Oral, kidney, single dose therapy for UTI
What is fosfomycin synergistic with
Beta lactamase, aminoglycosides, fluoroquinolones
What are polymixin B and E used for
Active against gram - except proteus and neisseria
Limited to topical use due to renal toxicity
When is polymixin B and E specifically used for
Salvage therapy
