Term
Antibiotic pharmacodynamics:
Emax?
EC(IC) 50?
bacteriostatic?
bacteriocidal? |
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Definition
Emax= conc at which the maximum inhibition of bacterial growth is observed
EC 50= conc where half of Emax is reached
bacteriostatic= inhibition of bacterial growth, but no killing (left up to immune system)
bacteriocidal= kills 99.9% of bacteria |
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Term
| reasons for a musculocutaneos AB injection? |
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Definition
| length of action needs to be long, poor venous access |
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Term
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Definition
the minimum inhibitory conc (min conc of drug needed to inhibits visible growth)
the minimum bactericidal conc (the lowest conc needed to achieve total of 99.9% reduction of bacteria) |
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Term
| difference between time-dependent (conc-independent) and conc.-dependent drugs? |
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Definition
time dependent drugs exert effects steady at a fixed killing rate once a threshold conc is reached. increasing the conc beyond this point does not have any added benefit.
for conc-dependent agents, extent and rate of killing is increased progressively with higher antibacterial concentrations |
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Term
| when can resistance be seen? |
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Definition
| when Cmax:MIC (maximum inhibitory conc) falls below 3:1 |
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Term
| times to considered prophylactic AB therapy |
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Definition
| surgical procedures (given 60 mins prior and not more than 24 hours post), immunosupressed patients, high risk for endocarditis (a dental procedure concern) |
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Term
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Definition
| wide spectrum dosing before the pathogen is identified because delaying could be dangerous |
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Term
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Definition
intermediate resistance= shifting of the IC50 to the right
true resistance= a decrease of the Emax |
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Term
| ways efficacy of drugs is decreased? |
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Definition
reduced entry- loss of alterations of porin channels (as in gram neg bacteria)
enhanced export- efflux pumps pump drug out of cell
modifying enzymes- produced by bacteria and inactivate drug
modification of activating enzymes- prodrug is unable to become active form |
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Term
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Definition
| MOA: B-lactam ring blocks enzyme that inhibits bacs from performing cell wall synthesis (inhibited by LACATAMASE which some bacs produce) |
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Term
| penicillin-binding proteins |
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Definition
enzymes on the surface of some bacteria which have different affinity for different B-lactams. transpeptidases are also in this family and transpeptidases are essential to PDG linkage in the bacterial cell wall
B-lactam which interrupt this synthesis will activate a cell autolysis |
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Term
| bacteria which are resistant to B-lactams |
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Definition
legionella pneumophila, clamydia (because they are intracellular bacteria and B-lactam can't penetrate host cell)
mycoplasma (doesn't have PDG)
those with exceptionally small or selective porins |
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Term
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Definition
G pos. bacs produce a lot of it extracellulary
G neg. bacs have some located in their periplasmic space |
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Term
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Definition
Class A:
TEM-1, ESBL, KPC carbapenease, SHV-1
a SERINE protease
Class B:
a Zinc dependent metalloproteinase
broad spectrum against many B-lactams
Class C:
a SERINE protease
AmpC, inducible (often coded on chromosome)
Class D:
a SERINE protease
OXA B-lactamases which confer ampicillin resistance and is highly hydrolytic to oxacillin and cloxacillin |
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Term
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Definition
-highly effective with low toxicity
-primarily renally excreted
-maybe one of the most common drugs to have hypersensitivity to
-a hapten meaning it is small and cannot elicit an immune response unless it complexes with something bigger
-should not be given inrathecally due to encephalitic risk
-compete at OATP transporters
-may disrupt the effectiveness of oral contraceptive
-may disrupt proton pump which effects stomach acidity, lowering it, causing migration of native flora
-poor prostate, eye, and CSF penetration because they have thighs junctions |
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Term
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Definition
often nosocomial
usually caused by elimination of a C diff competitor by an AB |
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Term
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Definition
-aqueous and delivered intramuscularly or intravenously
-long acting (2-4 weeks), good for syphilis when BENZATHINE is added
-largely effective against many G pos. aerobes and anaerobes, some neisseria and haemophilis strains (G neg.) |
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Term
| bacterial resistance to Penicillin G |
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Definition
-many G neg., intrinsic
-staph aureus, produces penicillinases that inactivate penicillin G
-strep pneumo |
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Term
| cautions of natural penicillins |
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Definition
| hypersensitivity, seizures, electrolyte disturbances, jarisch-herxheimer rxn (complication of syphilis treatment) |
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Term
| what are NAFCILIN, oxacillin, dicloxacillin, and cloxacillin |
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Definition
penicillinase-resistant penicillins
bulky resides on R-side groups and therefore prevent staphylococcal B-lactamases
best used for methicillin-SENSITIVE staph aureus and staph epidermidis, toxic shock syndrome, septic arthritis (not as active as penicillin G against other microbes)
ADVERSE SE: hepatitis and interstitial nephritis |
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Term
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Definition
ampi and amox (amino group adds hydrophilicity thereby increasing their infiltration of enterobacteriacae)
ampicillin has been shown to positively effect meningitis by entering CSF, may lead to C diff superinfection, and is useful for UTI
amos and amp have a similar equivalent spectrum to penicilin G with pneumococi added
Highly susceptible to Class A B-lactamases, usually needs to be administered with an class A inhibitor
pseudomonas aeruginosa in inherently highly resistant |
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Term
| therapeutic uses of Aminopencilins |
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Definition
amox and amp are best for pen-sensitive and pen-resistent s. pneumoniae, UTIs, meningisitis, upper and lower respiratory tract infections
ADVERSE SE:
non-allergic rash (especially when allopurinol has also been used); need to be sure its non-allergic though, not a hypersensitivity rxn |
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Term
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Definition
good for G pos. cocci including B-lactamas-producing S. aureus (NOT MRSA), and G neg. anaerobes
good for mixed intrabdominal and pelvic infections |
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Term
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Definition
| good for treatment of acute otitis in children, sinusitis, animal bite wounds, cellulitis |
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Term
| piperacillin, ticaracillin pharmacokinetics and other facts |
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Definition
piperacillin (a uridopenicillin), ticaracillin (a carboxypenicillin) are both are given parentally because they are unstable in gastric acid
ideal for patients suffering from severe infections by gram negative bacteria
both are antipseudomonal penicillins, piperacillin being the superior of the two with added effectiveness against klebsiella and some enterbacteracae |
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Term
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Definition
| widest spectrum of all penicillins |
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Term
| clavuanate, sulbactam, tazobactam |
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Definition
B-lactamase inhibitors frequently partnered with antipseudomonal penicillins
they are suicide inhibitors meaning they irreversibly bind to many B-lactamases
effective against many class As, and plasmic encoded B lactamase produced by staph
they are INEFFECTIVE against class C |
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Term
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Definition
-structurally and functionally closely related to penicillins
-widely distributed
-acid stable so can be IV, IM, or oral
-CSF penetration increases through generations
-mainly renally excreted (except for ceftriaxone, which is through bile and fecal and cefotaxime which undergoes partial hepatic) |
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Term
| added features of cephalosporins through generations |
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Definition
1st - good for G pos. and some aerobes G. neg.
2nd - some added G neg. microbes
3rd - good for G pos. and aerobic G. neg. and enterobacteriacae. some are able to cross CSF
4th - some added resistance to hydrolysis from many plasmid and chromosome based B-lactamases except for KPC in Class A
5th - added strep, staph, and MRSA. no activity against extended-spectrum B-lactamases in Class A |
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Term
| cephalosporin is Ineffective against: |
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Definition
G. pos: pen-resist. S. pneumo, meth-resist. S. epiderm., C. diff, enterococcus
G. neg: KPC producing enterobacteraceae, campylobacter jejuni
mycoplasma, L. pneumo, chlamydia
ESBLs, class C |
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Term
| First Gen Cephalosporins of importance |
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Definition
| CEFAZOLINE - 60 mins prior to surgery CEPHALEXIN - oral, every 6 hours |
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Term
| Second Gen Cephalosporins of importance |
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Definition
| CEFOXITIN and CEFOTETAN - cephomycins with activity against B. fragilis which is needed around surgery CEFOTETAN- activity against B. fragilis |
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Term
| severe potential side effect of antipseudomonal ABs |
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Definition
| they are formulated with Na+ salts, therefore, any person at risk for cardiac failure should be careful due to the likely increase in BP |
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Term
| how are almost all B-lactams eliminated? |
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Definition
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Term
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Definition
| an accumulation of like organisms in a tissue or organ region. the population is very increased, growth slows, and there is a lot of sharing of resistance genes |
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Term
| requirement for the efficacy of B-lactams |
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Definition
| the bacteria need to be proliferating meaning their cell walls need to be remodeling |
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Term
add benefits of gen. 3 cephalosporins
name four |
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Definition
increased ability to pass BBB (for meningitis), broad spectrum for G pos and G neg
poor against B. fragilis
Ceftriaxone and Cefotaxime and Cefdinir (Lacks anaerobic activity) Ceftazidine (for pseudomonas) |
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Term
| when to use a generation 4 cephalosporin |
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Definition
| use CEFEPIME for severe infection, psuedomonas |
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Term
| some side effects of CEFTRIAXONE |
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Definition
▫Cholestatic hepatitis/gallbladder disease
▫Hyperbilirubinemia in neonates (could cause encephalopathy)
▫Precipitation of Ca2+-containing solutions |
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Term
| some side effects of CEFETAN |
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Definition
▫Hypoprothrombinemia by inhibition of Vitamin K activation
▫Disulfuram-like reaction |
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Term
| what is imipenem-cilastatin used for? |
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Definition
in the carbapenem family, it penetrates CSF
-has a large spectrum for G pos and neg including pen-resistant s. pneumo and pen-sens enterococcus faecilis
*treatment of choice for ESBL-expressing enterobacteriacae
primarily renal excretion
cilistatin is an inhibitor of the dehydrogenase that inactivates imipenem |
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Term
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Definition
it is for G pos organism, but has inferior activity against pseudomas and acintobacter
like all carbapenems, it is inactivated by class A and B |
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Term
| adverse effects of carbapenems |
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Definition
•Seizures: greatest risk with the use of imipenem; patients with renal insufficiency are at increased risk
•Hematologic: Bleeding, agranulocytosis, leukopenia have been reported.
•GI: Nausea, vomiting, diarrhea are relatively common
•C. difficilesuperinfection |
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Term
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Definition
a MONOBACTAM
highly effective against G neg aerobic cocci and bacilli, but is too narrow to be used for empirical dosing
used for pseudomonal lung infections in patients with cystic fibrosis
has a relatively low immunogenic potential (limited crossing-over with other B-lactams)
hydrolyzed by Class C and D |
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Term
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Definition
a glycopeptide that is poorly absorbed, renally eliminated, good penetration to CSF
MOA- stops cross linking of sugars by preventing incorperation of NAM and NAG which is the step for transpeptidization; binds to D-Ala-D-Ala
it is only for G pos because cannot penetrate porins, MRSA, MRSE E. faecalis and facieum
resistant to enterococci which express a VanA gene and sometimes S. aureus |
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Term
| what to use vancomycin on? |
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Definition
MRSA
Enterococcal endocarditis
Pneumococcal infections (penicillin res.)
C. diff
pen. res. S. pneumo (bacterial meningitis) |
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Term
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Definition
•Hypersensitivity reaction
•Red man syndrome
•Phlebitis at injection site
•Ototoxicity (rare)
•Nephrotoxicity (currently uncommon)
Reacts with AMINOGLYCOSIDES |
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Term
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Definition
renally excreted, poor slow distribution
conc. dependent
innactivated by pulmonary surficants
MOA: binds to cell membrane and starts creating a Calcium complex which will form a pore from which intracellular potassium can escape depolarizing bacteria |
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Term
what daptomycin works on, what it doesn't.
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Definition
works on:
ALL G POS BACTERIA
MRSA, MRSE, VISA, VRSA, VRE
resistance:
ALL G neg BACTERIA
any left side endocarditis and pneumonia (due to pulmonary surficant inactivation) |
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Term
| side effects of DAPTOMYCIN |
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Definition
| myopathy; HMG CoA reductase inhibitors have been linked to additive muscle toxicity |
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Term
| What is the antibiotic of choice for surgical prophylaxis (an appendectomy) in this type of procedure (non-allergic patient)? Why? |
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Definition
Cefoxitin
•To reduce the incidence of septic complications
•For coverage of anaerobes that populate the distal parts of the intestine, particularly B. fragilis |
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Term
| what are some good beta-hemolyzers |
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Definition
| all Group A and Group B Streptococci, most strains of S. aureus, some strains of Clostridia, and about half of all strains of E. coli |
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Term
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Definition
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