Antibiotics 1-3 Flashcards
chemotherapy definition
treatment of a disease with the use of chemicals to kill or impair the growth of microorganisms or cancerous cells
selective toxicity definition
aimed at killing or impairing growth of the specific target organism without harming the host
empirical therapy definition
treatment of a symptomatic patient without further testing or confirmation of the organism
narrow spectrum definition
drug that has an effect on one type or species of organism
prophylactic therapy definition
treatment in the absence of infection in order to prevent disease
definitive therapy definition
treatment given when the pathogenic organism has been identified and appropriate drug identified
broad spectrum definition
drug that has an effect on a wide variety of organisms
preemtive therapy definition
treatment of high risk patients that have become infected but are asymptomatic (treating a patient who has symptoms and then treat his family even if they aren’t showing symptoms but illness is very contagious)
suppressive therapy definition
generally a low dose therapy used as a secondary prophylaxis
LPS - effect on antibiotic?
slows or prevents penetration of bulky, HMW antibiotics like erythromycin
hydrophillic pores - effect on antibiotics
can be utilized to help water soluble drugs like sulfonamides to enter cells
Nutrient receptor proteins on outer bacterial membrane - effect on antibiotics:
Agents that are structurally related to nutrients such as sideromycins can use these to enter cell
bacterial folate synthesis inh drugs:
- sulfonamides
- trimethoprim
(bacterial dihydrofolate inh)
RNA polymerase inh drugs:
rifampin
cell membrane inh drugs:
amphetericin
ketoconazole
polymyxin - binds phospholipids in cell membrane and distrupts structure like LPS
cell wall synthesis inh drugs:
1) Beta-lactam antibiotics:
- carbapenems
- cephalosporins
- monobactams
- penicillins
2) Others:
- bacitracn
- fosfomycin
- vancomycin
DNA gyrase inh drugs:
fluoroquinolones
Protein synthesis inh drugs:
aminoglycosides chloramphenicol clindamycin macrolides mupiocin streptogramins tetracyclins
bactericidal drugs do what?
kill the bacteria
bacteriostatic drugs do what?
inhibits growth of the bacteria but does not kill the bacteria
WHat are the most common resisitant organisms? Mnemonic?
ESKAPE
- Enterococcus faecium
- Staphylococcus aureus
- Klbsiella pneumoniae
- Acinetobacter baumanni
- Pseudomonas aeruginosa
- Enterobacter species
Daptomycin
- Tx use?
- Resistance how?
- for complicated skin infections, bacteremia and endocarditis
- specific gene mutation (mprF) that results in a change in membrane charge = overall net positive (More lysine added) –> repels the antibiotic with positively charged daptomycin properties
Tetracycline
- Tx use?
- Resistance how?
- broad spectrum antibiotic used to treat a variety of conditions such as acne, bronchitis, gonorrhea, and syphilis
- expression of an efflux pump removes antibiotic from the cell (N gonorrhea, E Coli, S pneumo, P Aeruginosa
Metronidizole
- Tx use?
- Resistance how?
- abdominal infections, vaginitis, C Difficile, and brain abscess
- metronidazole needs to be reduced to generate reactive oxidative species. Mutation in rdxA gene reduces/decreases activiation
Aminoglycosides (streptomycin)
- Tx use?
- Resistance?
- used with other drugs to tx endocarditis, tularemia, plague, and tuberculosis
- aminoglycoside-modifying enzymes chemically modify the antibiotic and alter binding of drug to its target
Amoxicillin
- tx use?
- resistance?
- broad spectrum antibiotic
- Beta-lactamase breaks beta lactam ring of amoxicillin (and other penicillins and cephalosporins)
Trimethoprim and sulfonamides
- Tx use?
- resistance?
- commonly used in combo to tx UTI
- these guys inh folate synthesis so the organism expresses drug insensitive enzymes and can still make the folate
Vancomycin
- tx use
- resistance?
- tx bloodstream infections, endocarditis, and meningitis
- substitution on the peptidoglycan stem so that the drug can no longer bind the target
- How to recognize penicillin type drugs?
- MOA?
- name ends in -illin
- cell wall synthesis inhibitors
- How to recognize cephalosporin type drugs?
- MOA?
- name begins with cef-
- cell wall synthesis inhibitors
- beta-lactamase inhibitor drug?
- MOA?
- clavulanic acid
- given with other beta-lactam drugs to help with cell wall synthesis inh - prevents bacteria from breaking down the acting beta-lactam
- monobactam drug?
- MOA?
- aztreonam
- cell wall synth inh
- glycopeptides drug?
- MOA?
- vancomycin
- cell wall synthesis inh
- polypeptide type drug?
- MOA?
- bacitracin
- cell wall synthesis inh
- How to recognize carbapenem type drugs?
- MOA?
- drug name ends in -enem
- cell wall synth inh
- phosphoenolpyruvate type drug?
- MOA?
- fosfomycin
- cell wall synthesis inh - (blocs early step - UDP-N-acetylmuramic acid)
- Lipopeptide type drugs?
- MOA?
- daptomycin
- targets the membrane - bacteria cant control depolarization=death
- detergent type drug?
- MOA?
- polymyxin B
- targets the membrane - binds phospholipids in cell membrane and distrupts structure like LPS
- how to recognize the tetracyclines drugs?
- MOA?
- name ends -cycline
- protein synthesis inh
- aminoglycoside type drugs?
- MOA?
- amikacin
- gentamincin
- kanamycin
- neomycin
- streptomycin
- tobramycin
-protein synthesis inh
- macrolide type drugs?
- MOA?
- clarythromycin
- azithromycin
- erythromycin
-protein synthesis inh
- How to recognize sulfonamide type drugs?
- MOA?
- sulfadiazine
- sulfamethizole
- sulfamethoxazole
- name begins with sulfa-
- folate synth inhibitors - mimics PABA and competes for binding in dihydrofolic acid
- trimethoprim type drugs?
- MOA?
- pyrimethamine
- trimethoprim
-folate synth inh
- How to recognize fluoroquinolone type drugs?
- MOA?
- usually end in or have -floxacin somewhere in the name
- gyrase inhibitors
- Metronidazole type drugs?
- MOA?
- metronidazole
- DNA damage???
MOA/What enzymes to cell wall synthesis inh drugs target?
PBPs - penicillin-binding proteins
many different types
- What type drugs belong to the beta-lactams?
- How do these drugs fight bugs (bactericidal/static)?
- penicillins
- cephalosporins
- monobactams
- carbapenems
-bactericidal
Which penicillins are resistant to bacterial beta-lactamases?
methicillin
nafcillin
oxacillin
penicillin compounds (beta lactam antibiotics) to know for this exam? -drug derived from nature or synthetic?
- penicillin G (natural)
- penicillin V (natural)
- amoxicillin (synthetic)
- methicillin (synthetic resistant to beta-lactamases)
Spectrum of penicillin drugs?
MOA for penicillins?
- the natural agents has limited spectrum
- the synthetics have broader spectrum
- inh PBPs!!
- Key adverse effect for penicillin compounds?
- Secondary infections?
- *-hypersensitivity - rash, itching, respiratory issues, anaphylaxis
- CNS effects - confusion
- blood- hemolytic anemia, thrombocytopenia
-secondary infections=vaginal candidiasis
If patient has anaphylactic adverse reaction to penicillin drug then what drug type to give/not give?
- Dont give other beta-lactams bc cross reactivity
- -> so no cefalosporins, carbapenems, monobactams or other penicillins
Narrow spectrum beta-lactam antibiotics?
-sensitive organisms?
- penicillin G
- penicillin V
-sreptococci, pneumococci, meningococci, treponema pallidum
Very-narrow spectrum beta-lactam antibiotics?
-sensitive organisms?
- methicillin
- nafcillin
- oxacillin
- ONLY ONE THAT IS BETA LACTAMASE RESISTANT
- staph (but NOT multi-drug resistant stap)
Broad spectrum beta-lactam antibiotics?
-sensitive organsims?
- ampicillin
- amoxicillin
-gram+ cocci, E Coli, Haemophilus Influenzae, listeria monocytogenes, borrelia burgdorferi, H pylori