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Pharm 2 Test 2
Boooooo
180
Veterinary Medicine
Professional
02/13/2012

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Term
What are examples of aminoglycosides?
Definition
Neomycin
Paromomycin
Tobramycin
Amikacin
Gentamicin
Term
What are the physiochemical properties of aminoglycosides?
Definition
Hydrophilic
Lipid insoluble
Minimally absorbed from gut
Minimally bound to protein (but can bind to debris)
Term
What is the mechanism of action of aminoglycosides?
Definition
Protein synthesis inhibition
Term
Are aminoglycosides bacteriostatic or bactericidal?
Definition
Bactericidal (only protein inhibitor that is!!!)
Term
Do aminoglycosides have good or poor penetration into bacteria?
Definition
Poor
Term
What is penetration into bacteria dependent on for aminoglycosides?
Definition
Energy dependent phase I - Oxygen - blocked by hyperosmolarity, low pH, and anaerobic conditions
Energy dependent phase II - disruption of membrane and ion leakage
Term
What does tobramycin (aminoglycoside) have the best potency against?
Definition
Pseudomonas aeruginosa
Term
Which aminoglycoside has the broadest spectrum?
Definition
Amikacin
Resistant to enzymes produced by enterobacteriaceae (less resistance)
Term
Which aminoglycoside is used for amoebas and helminths?
Definition
Paromomycin
Term
What is the route of administration for aminoglycosides?
Definition
IV, IM, or SC for systemic effects
PO for local GI effects
Term
What is the Vd for aminoglycosides?
Definition
Small
Term
How well do aminoglycosides penetrate into the CNS?
Definition
Not well at all!
Term
Where are the sites of tissue concentration of aminoglycosides?
Definition
Renal cortex
Cochlear tissue
Term
What is the excretion of aminoglycosides?
Definition
Kidneys
[Urine] may be 100x [serum]
Term
What happens when you administer an aminoglycoside intramammary?
Definition
Diffuses into plasma (enough to produce prolonged renal residues)
Term
What is the efficacy of aminoglycosides dependent on?
Definition
Peak
1x/day admin
DO NOT ADMIN BY CRI!!
Term
What are the adverse reactions of aminoglycosides?
Definition
Renal toxicity (esp neomycin)
Ototoxicity
Neuromuscular blockade
Excessive WDT
Term
What are the phases of renal toxicity with aminoglycosides?
Definition
Initial nonazotemic phase
Azotemic phase - non reversible
Term
How do cats and dogs present differently with ototoxicity caused by aminoglycosides?
Definition
Cats - vestibular symptoms
Dogs - auditory symptoms
Term
What are the drug-drug interactions of aminoglycosides?
Definition
Loop or osmotic diuretics - increase kidney ADE
General anesthetics/NMJ blockades
Term
What is the best way to avoid nephrotoxicity with aminoglycosides?
Definition
Allow [serum] to drop below a trough prior to next dose
Term
What are the rules for aminoglycoside use in food animals?
Definition
Only injectable label is for 3d old pigs
Gentamicin pinkeye spray
NO TOLERANCE for gentamicin in bovine tissue
Neomycin oral use only
Shouldn't be used (Academy of Veterinary Consultants, AABP, National Cattlemen's Beef Association, and AVMA)
Term
What is the number for FARAD (Food Animal Residue Avoidance Depletion program)?
Definition
1-888-USFARAD
Term
What are the examples of aminocyclitols?
Definition
Spectinomycin
Term
What are the physiochemical properties of aminocyclitols?
Definition
Water soluble
Poorly lipid soluble
Term
What is the mechanism of action of aminocyclitols?
Definition
Inhibit protein synthesis
Bacteriostatic
Term
What are the routes of administration of aminocyclitols?
Definition
IV, IM, or SC
PO for local GI effects
Term
What are the pharmacokinetics of aminocyclitols?
Definition
Short T1/2
Low Vd
Limited distribution beyond ECF
Term
What are the adverse reactions to aminocyclitols?
Definition
Neuromuscular blockade
Term
What kind of antibiotics are the penicillins?
Definition
Beta-lactams
Term
What are examples of penicillins?
Definition
Na/K Pen G
Procaine Pen G
Benzathine Pen G
Term
What are examples of penicillinase-resistant penicillins?
Definition
Oxacillin
Term
What are examples of aminopenicillins?
Definition
Ampicillin
Amoxicillin
Term
What are antipseudomonal (extended spectrum) penicillins?
Definition
Ticarcillin
Term
What are the examples of potentiated penicillins?
Definition
Amoxicillin-Potassium clavulanate
Term
What are the physiochemical properties of penicillins?
Definition
Water soluble
Organic acids
Poor lipid solubility
Term
What part of the penicillin molecule is needed for clinical efficacy of penicillins?
Definition
Nucleus containing beta-lactam ring
Term
How are penicillins administered?
Definition
Na/K pen G and amoxicillin - IV
Benzathine/procain - IM or SC (IV admin may result in procain toxicity)
Term
What is the mechanism of action of penicillins?
Definition
Inhibit bacterial cell wall synthesis
"Fake bricks in a wall"
Can't withstand osmotic pressure
Term
When are penicillins most effective against bacteria?
Definition
When they are growing a dividing!!!
Term
What are the mechanisms of resistance for gram + bacteria to penicillins?
Definition
Inducible, plasmid-mediated enzymes
Destroy beta-lactam ring
Ex: mecA gene for methicillin in S. aureus
Term
What are the mechanisms of resistance for gram - bacteria to penicillins?
Definition
Inherent resistance due to lack of penicillin binding proteins
Low permeability to beta-lactams
Beta-lactamase enzymes
Ex: extended-spectrums have issues with Enterobacter, Klebsiella, and E. coli
Term
What is the only acid stable version of pen G suitable for oral use?
Definition
Pen V
Term
Where are penicillins ionized?
Definition
Plasma (pKa 2.7)
Term
What is the Vd of penicillins?
Definition
Small - confined to ECF
Term
How are penicillins excreted?
Definition
Kidney
Term
Which is more orally bioavailable - amoxicillin or ampicillin?
Definition
Amoxicillin
Term
Are beta-lactams bacteriostatic or bactericidal?
Definition
Bactericidal
Term
What is the efficacy of beta-lactams linked to?
Definition
Time the serum concentration remains above the MIC of the pathogen
Term
Are penicillins safe?
Definition
YES! Anaphylaxis may occur (expect cross-sensitivity)
Term
How long before racing should you discontinue procaine pen G to avoid procaine residues in horses?
Definition
30d
Term
What is the main adverse effect of IV K pen G in horses?
Definition
K pen squirts
Term
How do non-ruminant herbivores respond to pen G?
Definition
OFTEN FATAL (rabbits, etc)
You can still use it in horses!!!
Term
What are examples of beta-lactamase inhibitors?
Definition
Clavulanic acid
Sulbactam
Tazobactam
Term
What is the mechanism of action of beta-lactamase inhibitors?
Definition
Very little antimicrobial activity on their own
Bind with chromosomally-mediated and plasma-mediated penicillinases
Term
When should you stop administration of amoxicillin/clavulanic acid in cats?
Definition
When they stop eating
May drive them into hepatic lipidosis!
Term
What is the main adverse effect of amoxicillin/clavulanic acid?
Definition
GI upset
Term
Why are cephalosporins classified by activity ("generations")?
Definition
Structure and activity not consistently related
Term
What are examples of first generation cephalosporins?
Definition
Cefadroxil
Cephalexin
Cefapirin
Cefazolin
Term
What are examples of third generation cephalosporins?
Definition
Cefpodoxime
Proxetil
Ceftriaxone
Ceftiofur Na, HCl, and CFA
Cefovecin
Term
What are examples of fourth generation cephalosporins?
Definition
Cefepime
Term
What are the physiochemical properties of cephalosporins?
Definition
Water soluble
Poorly lipid soluble
Term
What is the mechanism of action of cephalosporin?
Definition
Same as penicillin
Term
What is the efficacy of cephalosporins related to?
Definition
Time above MIC
Bactericidal
Term
What is unique about cefovecin?
Definition
Injectable third-gen
Long T1/2 (5.5d dogs, 6.9d cats)
Does not reach MIC90 for E. coli, Pseudomonas, or enterococci
Term
Why shouldn't you use cephalosporins IV in cattle?
Definition
No points! (same pharmacokinetics as IM)
Term
Why does ceftiofur CFA have such a long half life?
Definition
Flip-flop kinetics
Protein binding
Can only inject at base of ear!!
Term
What is unique about ceftiofur HCl?
Definition
Comes ready to use in a cottonseed oil carrier (unlike ceftiofur Na)
Term
What is ceftiofur CFA labeled for?
Definition
BRD (inject at base of ear)
Swine respiratory dz
Equine lower respiratory tract infections
Term
What form does cefpodoxime proxetil come in?
Definition
Tablets
No activity against P. aeruginosa
Term
What pathogens are displaying significant cephalosporin resistance?
Definition
S. Heidelberg in poultry
S. Newport and S. Typhimurium in dairy cattle
Term
What pathogen will susceptibility testing look rosy for using ceftiofur (but really the drug won't work)?
Definition
Staph (drug and metabolite don't have equal activity)
Term
What are the adverse reactions to ceftiofur?
Definition
Anaphylaxis (cross reactivity with penicillins)
Hepatitis, agraulocytosis, and thrombocytopenia (high dose/prolonged use)
Anorexia, vomiting, diarrhea
Seizures (with phenobarb)
Term
Is extralabel use of ceftiofurs allowed in food animals?
Definition
NO! Cannot alter regimen either!
Term
What are examples of the carbapenems?
Definition
Imipenem
Meropenem
Term
What bacteria have shown resistance to carbapenems?
Definition
Pseudomonas
Enterococcus faecium
MRSA
Term
What are the routes of administration for carbapenems?
Definition
IM, SC, usually IV
Term
Which carbapenem is better for SC injection?
Definition
Meropenem - almost complete absorption, no pain (like imipenem), injection volume lower, more stable
Term
What are the examples of monobactams?
Definition
Aztreonam
Term
What are examples of fluoroquinolones?
Definition
Enrofloxacin - injectable and oral
Difloxacin - tablets
Orbifloxacin - tablets
Marbofloxacin - tablets
Danofloxacin - injectable
Term
What is the proper way to use fluoroquinolones extralabel?
Definition
YOU CAN'T!
Term
What are the physiochemical properties of fluoroquinolones?
Definition
Poor lipid solubility except in pH range of 6-8, so EXCELLENT LIPID SOLUBILITY WHEN USED CLINICALLY!
"Oral aminoglycosides"
Term
What is the mechanism of action of fluoroquinolones?
Definition
Topoisomerase inhibition - leads to DNA strand breaks
Rapidly bactericidal
Mammalian topoisomerase unaffected
Term
What are the mechanisms of resistance to fluoroquinolones?
Definition
Alteration of target enzymes (DNA gyrase and topoisomerase IV)
Decreased drug permeation into bacterial cells
Plasmid and non-plasmid encoded
Term
What is the mutant prevention concentration?
Definition
Concentration above which two concurrent mutations for resistance must occur for an organism to grow
Term
How bioavailable are fluoroquinolones?
Definition
Very high from oral, IM, or SC
Rapidly absorbed
Term
Can fluoroquinolones penetrate the brain and prostate?
Definition
YES!
Term
How are fluoroquinolones excreted?
Definition
Kidney
Some biliary
Term
How are fluoroquinolones metabolized?
Definition
De-ethylation rxn in the liver
Transforms enrofloxacin to ciprofloxacin
Term
What is the efficacy of fluoroquinolones associated with?
Definition
Peak concentration (target 8-10x pathogen MIC)
Ratio of AUC to pathogen MIC (target >125)
Term
What are the adverse reactions of fluoroquinolones?
Definition
Articular cartilage damage (pups, foals)
Retinal degeneration (cats, guanacos - enro)
Increased seizure frequency (dogs - w/ phenobarb)
Irritating when infused inutero (horses)
Term
What are the drug interactions for fluoroquinolones?
Definition
Some have strong affinity for CYP-450 enzyme IA-2
Can raise serum theophylline levels
Term
What are examples of macrolides?
Definition
Erythromycin
Clarithromycin
Azithromycin
Tulathromycin
Tylosin
Tilmicosin - VFD
Tildipirosin
Term
What are the physiochemical properties of the macrolides?
Definition
Basic compounds
Lipid soluble
Alcohol soluble
Poorly water soluble
Term
What is the mechanism of action of macrolides?
Definition
Inhibit protein synthesis
Bacteriostatic (newer human ones bactericidal)
Term
How is tilmicosin administered?
Definition
SC in cattle
Oral admin in feed for swine - VFD
IV admin fatal!!!
Term
How is azithromycin administered?
Definition
Oral
Injection (may be irritating)
Term
What is the Vd for macrolides?
Definition
>1L/kg
Concentrate in tissues!
Long T1/2 (protein binding)
Term
How are macrolides eliminated?
Definition
Primarily through bile
Minimal renal contribution
Term
What is the efficacy of macrolides dependent on?
Definition
Time above MIC
Azithro and clarithromycin - peak concentration
Term
What are the adverse reactions to macrolides?
Definition
GI effects
Injection sites (food animals)
Temperature regulation (hyperthermia in foals)
Term
What population can tilmicosin NOT be used in?
Definition
Dairy cows (15-29d milk withdrawals!)
Term
What are examples of lincosamides?
Definition
Lincomycin
Clindamycin
Pirlimycin
Term
What are the physiochemical properties of lincosamides?
Definition
Basic (traps in milk)
Lipid soluble
Related to macrolides (but different structure)
Term
What is the mechanism of action of lincosamides?
Definition
Inhibit protein synthesis
Bacteriostatic
Toxin production inhibition
Term
What are the resistance mechanisms to lincosamides?
Definition
Gram - because of impermeable cell membranes and incompatible binding sites
Cross resistance with virginiamycin
Term
What is the efficacy of lincosamides dependent on?
Definition
Time above MIC
Term
What is a dosing precaution to take with lincosamides?
Definition
BAD TASTE!!
Esophageal damage bc cats won't swallow
Term
What are the adverse reactions/contraindications for lincosamides?
Definition
Death in nonruminant herbivores
Not recommended in ruminants and pigs
Diarrhea in nursing pups and kittens if dam given lincosamide
Fatality in pulmonic toxo cats
Term
What are examples of the nitroimidazoles?
Definition
Metronidazole
Term
Which nitroimidazoles can you use in food animals?
Definition
NONE!!!
Term
What is the mechanism of action of nitroimidazoles?
Definition
Reduction in the nitro group of anaerobic bacteria to produce unstable metabolites (which break DNA and inhibit repair enzymes)
Term
How well is metronidazole absorbed?
Definition
Well absorbed with variable (also tastes bad)
Term
What are the adverse effects of metronidazole?
Definition
Carcinogen (no food animals!!)
Nausea
Inappetance
CNS toxicosis (high doses)
Term
What are examples of the phenicols?
Definition
Chloramphenicol
Florfenicol
Term
What are the physiochemical properties of phenicols?
Definition
Very lipid soluble
High Vd (>1L/kg)
Chloramphenicol>Thiamphenicol>Florfenicol
Term
What is the mechanism of action of phenicols?
Definition
Protein synthesis inhibition
Chloramphenicol - aplastic anemia!! (dispense exam gloves for use)
Term
Why is chloramphenicol banned for use in food animals?
Definition
Possible irreversible aplastic anemia
Term
How are phenicols administered?
Definition
Chloramphenicol - capsules, injection
Florfenicol - IM, SC, oral (in water for swine)
Term
Why should you be careful using chloramphenicol in a neonate?
Definition
Deficient in glucuronyl transferase
Elimination very slow!
Term
What is the drug drug interaction of chloramphenicol?
Definition
Reduces glucuronide conjugation and oxidative pathways in the liver
Prolongs barbiturates
(CAREFUL WITH PHENOBARB)
Term
What is the efficacy of chloramphenicol associated with?
Definition
Time above MIC
Florfenicol - bactericidal
Term
What are the adverse effects of phenicols?
Definition
Human aplastic anemia
Bone marrow suppression
Excessive accumulation in patients with impaired renal and hepatic fxn
Gray baby syndrome - cats - circulatory collapse
Decreased H20 consumption, inappetance, diarrhea
Term
What are examples of sulfonamides/diaminopyrimidines?
Definition
Sulfadimethoxine
Sulfamethoxazole
Sulfamethazine
Sulfadiazine
Sulfadimethoxine + sulfamethazine
Sulfasalazine - careful in cats!!
Ormetoprim
Trimethoprim/sulfadiazine
Omretoprim/sulfadimethoxine
Term
What animal are sulfonamide drugs prohibited in?
Definition
Lactating dairy cows!
(Except approved use of sulfadimethoxine, sulfabromomethazine, and sulfaethoxypyridazine)
Term
What are the physiochemical properties of sulfonamides?
Definition
Each sulfa shows independent solubility in a solution
Weak acids (except trimethoprim - lipid soluble)
Not water soluble
Term
What is the mechanism of action of sulfonamides?
Definition
Compete with PABA for incorporation into the scheme for folic acid synthesis (which is used for purine synthesis) - decreases RNA and inhibits protein synthesis
Bacteriostatic (trimethoprim - cidal)
Term
What does cellular debris do to sulfonamides?
Definition
Lose activity!
Folic acid and purins readily available from environment
Term
What type of compound is synergistic with sulfonamides?
Definition
Diaminopyrimidine - bactericidal
Term
How prevalent is resistance to sulfas?
Definition
COMMON!
Term
What is the route of administration of sulfonamides?
Definition
Sulfadimethoxine - IV, oral
- +ormetoprim - tablets
Trimethoprim/sulfadiazine - IV, oral tablets/paste
Sulfamethiazine - oral, VFD, soluble powder
Sulfachlorpyridazine - IV, soluble powder
Sulfasalazine - oral tablets
Term
How well are sulfas absorbed?
Definition
Well orally!!
Differences between sulfas in degree of protein binding, Vd, and T1/2
Term
What is a common dosing regimen for sulfas?
Definition
Loading dose then maintenance dose
Term
How are sulfas excreted?
Definition
Renal
Biotransformation
Term
What does the efficacy of sulfas depend on?
Definition
Time above MIC
Bacteriostatic
(+diaminopyrimidine = cidal)
Term
What are the adverse effects of sulfas?
Definition
KCS
Neutropenia
Crystalluria
Enteric flora alteration
Injection sites (food animal)
Sulfaquinoxaline - antagonize Vit K
Decrease T3 and T4
Term
What are examples of the tetracyclines?
Definition
Chlortetracycline
Oxytetracycline
Tetracycline
Tigecyclin
Doxycycline
Term
What is the mechanism of action of tetracyclines?
Definition
Protein synthesis inhibition
Bacteriostatic
Term
How are tetracyclines administered?
Definition
Tetracycline - oral
Chlortetracycline - feed
Oxytetracycline - ophthalmic, oral, injectable
Doxycycline - oral, injection
Tigecycline - injection
Term
How well are tetracyclines absorbed?
Definition
Well absorbed from oral, IM, and SC
Term
Which is the tetracycline of choice for renal disease?
Definition
Doxycycline (eliminated through bile and GIT instead of kidney)
Term
What limits diffusion of doxycycline into tissues?
Definition
90% protein bound in dogs
99% protein bound in cats
Term
What drug can you use in flexor tendon contraction deformities in neonatal foals?
Definition
Oxytetracycline (high-dose IV)
Term
What are the adverse reactions of tetracyclines?
Definition
Nephrotoxicity (in dehydrated or renal dz)
Teeth staining in fetus and juveniles
GI effects (cats especially)
Cardiovascular dysfxn in horses
Injection site concerns (FA)
Photosensitivity
Term
What are examples of cyclic lipopeptides?
Definition
Daptomycin
Term
How is daptomycin administered?
Definition
IV
Term
What are the examples of glycopeptides?
Definition
Vancomycin
Term
How should vancomycin be used in food animals?
Definition
BANNED! Due to concerns about resistance development
Term
What agent is vancomycin the first line of defense against?
Definition
MRSA
Term
How well is vancomycin absorbed?
Definition
Oral - poor
IV - good
Term
What are the adverse effects of vancomycin?
Definition
Ototoxicity
"Redman Syndrome" - release of histamine (admin slowly)
Careful with aminoglycosides!!
Nephrotoxicity
Term
What are the examples of oxazolidinones?
Definition
Linezolid
Term
What is linezolid primarily used for?
Definition
VRE
MRSA
Term
How bioavailable is linezolid?
Definition
100% oral
Term
What are examples of the streptogramins?
Definition
Virginiamycin
Synercid
Term
How orally bioavailable are streptogramins?
Definition
0% systemically!
Term
What are the applications of synercid?
Definition
VRE
Resistant pneumococcus
MRSA
Term
What is the resistance to streptogramins?
Definition
Cross resistant with macrolides and lincosamides (group B streptogramins)
Term
What is mupirocin used for?
Definition
Topical infections
(Staph and Strep)
Term
Why is mupirocin only available for topical use?
Definition
Rapid metabolism after systemic administration
Term
What are bambermycins used for?
Definition
Growth promotion
Term
What else do bambermycins do?
Definition
Decrease shedding of E. coli and Salmonella and decrease resistance (YAY!)
Term
What are examples of ionophores?
Definition
Monensin
Lasalocid
Term
What is the mechanism of action of ionophores?
Definition
Complexes will cell wall sodium
Export of potassium/import of hydrogen
Drops intracellular pH
Bactericidal
Term
How do ionophores promote growth?
Definition
Eliminate some gram + population of rumen
Shifts VFA production toward proprionic acid
Decreases fog fever and methane
Term
What is another reason for using ionophores?
Definition
Coccidia
Term
What is isoniazid used for?
Definition
Antitubercular in people
Actinomyces bovis
Term
What is an example of a methenamine and what is it used for?
Definition
Formaldehyde
Urinary antiseptic
Term
Which nitrofurans are used in food animals?
Definition
NONE!
Mutagenic, carcinogenic
Term
What are nitrofurans used for?
Definition
UTIs
No oral bioavailability
Term
What is the mode of action of novobiocin?
Definition
Inhibits DNA supercoiling by inactivating DNA gyrase
Term
What are the examples of pleuromutilins (diterpines)?
Definition
Tiamulin (admin in food and water)
Term
What are the physiochemical properties of polymyxins?
Definition
Basic, cyclic decapeptides
Term
What is the mechanism of action of polymyxins?
Definition
Disrupts gram negative cell membranes (detergent)
Binds endotoxin
Term
What are the adverse effects of polymyxins?
Definition
Nephrotoxicity
NMB
CNS toxicity
Term
What are the examples of quinoxaline derivatives?
Definition
Carbadox
Term
What are the food animal concerns of carbadox?
Definition
Banned in Canada and the EU
Carcinogen
Term
What are examples of rifamycins?
Definition
Rifampin
Term
What is rifampin used for?
Definition
TB in people
Rhodococcus equi
Gram-negatives usually resistant
Term
What is the adverse effect of rifampin?
Definition
Turns you orange
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