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Pharm 2 - Antimicrobials 3

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isabellepjk's version from 2017-09-14 12:53

Penicillins General

Question Answer
β-lactams are type _________ killing kineticsType 2 - Time dependent (2 helped administer the 1st type of penicillin)
**Are β-lactams ‘cidal’ or ‘static’?Cidal (not part of Mac & Lin's stunt in the pool!)
**What is the mechanism by which Β-lactams work?Inhibits bacterial cell wall synthesis by binding to PBPs (Penicillin Binding Proteins) & stopping Transpeptidase
What are the 3 ways bacteria can become resistant to β-lactams?(1) They make β-lactamase
(2) They can ↓ their permeability
(3) They can ↓ the sensitivity of their PBP
What are the 5 groups of β-lactams?Penicillins
Cephalosporins
Cephamycins
Carbapenems
Monobactams
(1 pen in a CAR engine will make a cepha-cepha sound)
β-lactams are only effective against? (Broad def, not specific bact)Effective against rapidly growing organisms that synthesize peptidoglycan
---What are the differences btwn the various penicillins? (think structurally)Differences in acyl side chain
Which enzyme is effected by β-lactams?Transpeptidase enzyme
Which penicillin has a stupid long absorption when mixed w/ oil? How long exactly?Benzathine penicillin G, greater than or equal to 7 days (ben was impressive. that G could go for 7 days!)
Highest protein binding pencillins are?Cloxacillin & Nafcillin (80%) (I CLOX'ed NAf upside the head till protein came out)
**Where are penicillins mainly distributed?ECF (cant get into cell, thus narrow spect)
Penicillins have a low rate of distribution to which areas?CSF, aqueous humor & synovial fluid
---Milk to plasma equilibrium conc is?1:5
How much of the penicillins are metabolized, & why do we care?20%, which isnt much, but what is metabolized may turn to Penicilloic acid metabolite, which can act as a hapten causing allergic rxns
How are penicillins excreted? Exceptions?Kidney (glom filt & tubular secretion), except Nafcillin is excreted by bile
**How can you ↑ the half-life of penicillins?Admin w/ Probenecid, which competes w/ the penicillin for tubular secretion, so penicillin isn't secreted & keeps cycling in the body (penicillin probenecid)
Which penicillin causes convulsions & ataxia in cats & dogs?Sodium benzyl penicillin ( BEN SO caused a seizure in my dog/cat)
Acute cardiac toxicity caused by which drug?Procaine/potassium penicillin salts (kate is a pro at stopping your heart)
Anaphylaxis & CNS disorders in rodents, birds, snakes & turtles caused by?Procaine penicillin ( "propain" to all the things people tend not to like for some reason)
memorize

Natural Penicillins

Question Answer
Broad or narrow spectrum?Narrow (narrow, natrual)
What are the 2 members of the natural penicillins group?Penicillin V & Penicillin G
How can you extend the absorption time of Penicillin G?You can put it in oil (oil is Good)
**Which drugs of penicillin G do you NOT GIVE IV? EVER?Benzathine & Procaine formulations, bc these are repository (IM or intramammary) (BEN is a PRO at KILLING YOUR VEINS)
What are the 2 penicillin G drugs?Benzathine & Procaine (Ben is a PRO G)
**How do you formulate the natural pencillins to be injectable? (IM/SC or IV?)As SALTS!
(1) IM/SC as Na/K salts
(2) IV as Na salts
Which natural penicillins are given orally? Why are they able to be given orally?Penicillin V = oral. (Insert hilarious V-based oral joke gesticulation here). Oral bc they are ACID-STABLE (can survive stomach acid)
Which bacteria are natural penicillins effective against?Strep, Staph (non-penicillinase producing), coryne, haemophilis
anaerobic, G+/- Spirochetes
Which bacteria are natural penicillins NOT effective against?Pseudomonas, Enterobacteriaceae, Staph (penicillinase producing)
memorize

Semi-Synthetic Pencillins

Question Answer
What are the 3 groups of semi-synthetic penicillins?(1) Penicillinase-Resistant Penicillins
(2) β-lactamase sensitives aka broad spectrum aka aminopenicillins
(3) Extended spectrum/anti-pseudomonals
Penicillinase-Resistant Penicillins are ___ stable, which means you can administer them _________Acid, orally
Which Penicillinase-Resistant Penicillins have GOOD oral absorption?Oxacillin, Cloxacillin, Dicloxacillin (XXX in the mouth)
Which Penicillinase-Resistant Penicillins have POOR oral absorption?Methicillin, Nafcillin (say "na" to meth, it messes up your ORAL cavity)
Which Penicillinase-Resistant Penicillin is used for ophthalmic formulations?Benzathine Cloxacillin (BEN CLOX you in the EYE)
Which Penicillinase-Resistant Penicillins is excreted in the BILE?Nafcillin
Do Penicillinase-Resistant Penicillins treat bovine mastitis? ExplainYes, bc effective against Penicillinase Producing Staphylococcus sp., (which causes Bovine Staphylococcal Mastitis)
What are the drugs in the Penicillinase-Resistant Penicillins category?Cloxacillin
Oxacillin
Dicloxacillin

Methicillin
Nafcillin
(cloned oxen dye me (resistant) navy)
What are the 2 β-lactamase sensitive (broad spectrum/aminopenicillins) semi-synthetic penicillins?Amoxicillin, Ampicillin (Don't Mox that Amp, it's sensitive)
Which of the semi-synthetic β-lactamase sensitive (broad spectrum/aminopenicillins) drugs have related esters? Why would we want this?Ampicillin has related esters, which act as pro-drug & ↑ bio-availability.
What are the "pro-drug" forms of Ampicillin? (β-lactamase sensitive semi-synthetics)Bacampicillin
Hetacillin
Picampicillin
Talampicillin
( I am amped to Take pie back home)
**What must you co-administer w/ the β-lactamase sensitive semi-synthetic pencillins? (Aka broad spectrum, aka Aminopenicillins)Admin w/ β-lactamase inhibitors
What are the extended-spectrum anti-pseudomonal semi-synthetic penicillins? (5)(Anti-psedumonal MCT)
Ticarcillin
Carbenicillin
Piperacillin
Mezlocillin
Azlocillin
(Azlo Been Pipping Me Ticks - extensively)
By what route do you administer extended-spectrum anti-pseudomonal semi-synthetic penicillins?Parenteral route (to extend the dose, dont give orally)
What must you administer w/ the extended-spectrum anti-pseudomonal semi-synthetic penicillins?β-lactamase inhibitors
Semi-synthetic penicillins like to accumulate ___cellularly. Why?EXTRAcellularly, bc they are weak acids so they ionize & it is then difficult to get into the cell
Why do semi-synthetic penicillins have an increased half-life?They are plasma protein bound
How are most semi-synthetic penicillins excreted? Exceptions? Are they changed/metabolized at all?Excreted unchanged via the KIDNEY(urine), except Nafcillin is excreted via the bile, & 20% is changed to Penicilloic acid which may cause allergies
Aminopenicillins are?Broad spectrum penicillins/β-lactamase sensitive pencillins
---How can semi-synthetic penicillins cause allergies?Approx. 20% of the semi-synthetic pencillins undergo metabolism, & Penicilloic acid is produced which can cause allergic rxns
How can you increase the plasma concentration of semi-synthetic penicillins?You can administer Probenecid, which inhibits the tubular secretion of the semi-synthetic (competitively)
What are the 3 main side effects of semi-synthetics?(1) Allergic rxns (Penicilloic acid)
(2) Superinfxns (kills natural flora & makes room for a worse infxn)
(3) Ataxia/convulsions in dogs and cats(GABA Inhibited via Na Benzylpenicillin)
What 3 side effects can Procaine have?(1) Anaphylaxis/CNS in Rodents, birds, snakes, and turtles
(2) Excitement in horses
(pro at freaking out horses & choking out rodents)
(3) Acture Cardiac toxicity
Broad spectrum penicillins should be administered w/?β-lactamase inhibitors
Which penicillins have good oral availability?Penicillin V & Penicillinase Resistant Penicillin (Hard to resist the oral V)
memorize

Cephalosporins + β-lactamase Inhibitors

Question Answer
Are Cephalosporins resistant to β-lactamase?They are "more resistant"
What do 1st gen Cephalosporins treat?G+ & G- (1st gen=back to basics)
Which 1st gen Cephalosporin is given parenterally for small animals? Tx what?Cefazolin, G-'s ("zolin!", the small animal parent called, a negative tone in her voice)
Which 1st gen Cephalosporin is given to treat mastitis?Cephapirin (Her breasts were covered by nothing but her aprin)
Which 1st gen Cephalosporin is given as ophthalmic ointment for bacterial conjunctivitis in dogs & cats?Cefalonium (think of Jimmy Falon's eyes)
What do 2nd gen Cephalosporins work against?G-s, anaerobics
More effective than first gens for the G-
What are the Cephalosporins excreted in bile?Cefoperazone, Ceftriaxone (that pera spewed bile on the tria)
Which 3rd gen Cephalosporin is painful & irritating to cats & dogs?Cefotaxime (this drug is taxing on dogs & cats)
Which 3rd gen cephalo has a very long half-life? How long?Cefovecin. 5 days in dogs, 7 days in cats (vices take a LONG TIME to break...esp if youre a cat like me)
Which cepha is given as a single SC injxn in dogs & cats for pyoderma/skin infxns?Cefovecin (the long acting 1) (the fast & easy way is a vice)
Which 3rd gen cephalo is a pro-drug ester?Cefpodoxime Proxetil (po in 1st word & pro in the other word)
---Which 3rd gens are effective against pseudomonas?Cefoperazone, Ceftazidime (That pera owes me a lot of dime for giving me pseudomonas)
Which 3rd gen has a metabolite (name it) just as active as the unmetabolized form?Ceftiofur → Desfuroylceftiofur (just as effective) (furry doggies are so active!!)
What are the various conditions of various species that Ceftiofur is used to treat? (4)(1) Resp infxns in cattle & pigs
(2) UTIs in dogs
(3) Pleuritis in horses
(4) E-coli in poultry
(FUR in your lungs, around your lungs, in your pee, & in your E-coli poop)
---Which 3rd gens can cause hypoprothrombinemia? Why does this occur?Cefoperazone & Cefamandole: Inhibit Vitamin K → hypoprothrombinemia (that pera took my man k)
What is the spectum of the fourth gen ceph, cefquinome?broad spectrum
G+ cocci, G- rods, PSEUDO
More resistant to beta lactamases
Effective against Resistant infections
---How do β-lactamase inhibitors work?Competitive inhibitors of the β-lactamase binding site, so does not allow disintegration of β-lactam drugs
What are the 2 β-lactamase inhibitors?Clavulanic acid & Sulbactam
*Which 2 (3) cephalos are best against anaerobic infxns?Cefotetan & Cefoxitin (both are parenteral) (the fox tetan suffocated his enemies) (also Cephamycins)
Which cephas are effective against Bacteroides fragilis? What other property do they have?Cefoxitin & Cefotetan. More resistant to Cephalosporinases (the fox tetan named is strong & destroys fragile things)
Which cephas have high oral absorption?Cephalexin & Cefaclor (if you lex [licks] chlorine, it will absorb in your tongue)
~~Which cephas penetrate the BBB?Cefuroxime
Ceftriaxone
Cefotaxime
Ceftazidime
Ceftizoxime
(4 x's & 1 z pass the BBB))
What is the metabolism of the ceftios?Liver, to form deacetyl derivatives (so acetylation I think)
How are most cephos excreted?Kidney → glom filt & tubular secretion → urine
Which cepha can cause anemia & thrombocytopenia in dogs?Ceftiofur (their fur will be covered in blood!)
Which cepha decreases platelet aggregation?Cephalothin
What admin is Sulbactam exclusively?Only parenteral (the Sultan only enters in weird ways)
How does sublactam work?Increases antimicrobial activity of betalactam abx as clavulonic acid
What is tazobactam?drug that is used in combo with piperacilllin for IV use for resistant PSEUDO aeruginosa infections
memorize

Other β-lactams

Question Answer
Are Carbapenems cidal or static?Cidal (β-lactams are all cidal. also getting hit by a car will kill you)
What is the spectrum of Carbapenems?Broadest! (you can go far in a car!)
Can work against resistant infections
Rapid bactericidal activity
What are the 2 Carbapenems we care about?Imipenem, Meropenem
What is important to note about Imipenem? (A carbapenem)Use as LAST RESORT, it creates a NEPHROTOXIC metabolite, so it is ALWAYS administered w/ Cilastatin (a renal enzyme inhibitor) (I-M-I is S-O-S)
What is the adverse side effects of the carbapenems? (Imipenem, Meropenem)Seizures (having a seizure in the car is bad)
Why is Meropenem less harmful than Imipenem?Its more soluble, so there are less adverse effects (it's merely ~mero!)
What is the monobactam we care about?Aztreonam (can be used in penn. allergic PTx!)
What is the unique & useful trait about the monobactam Aztreonam?It has lower immunogenicity, so it can be used in PTx allergic to penicillins (Az safe az if it werent a penicillin)
Carbapenems used to treat what?Used for treating seriously resistant infxns
Which has the broadest spectrum of action?Imipenem (why it is used as last resort even tho it messes up your kidneys)
**Which drugs are OK for penicillin-sensitive patients?Carbapenems, Monobactams
**Which drugs are resistant to penicillinase enzymes?Cloxacillin
Oxacillin
Dicloxacillin

Methicillin
Nafcillin
**Which β-lactam can kill pseudomonas?Carbapenicillin (RUN OVER PSEUDOMONAS IN YOUR CAR)
What must you give w/ Imipenem?Cilastatin
memorize