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
|
|
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
|
|
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
|
|
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
|
|
Term
How well do aminoglycosides penetrate into the CNS? |
|
Definition
|
|
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
|
|
Term
What are the examples of aminocyclitols? |
|
Definition
|
|
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
|
|
Term
What kind of antibiotics are the penicillins? |
|
Definition
|
|
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
|
|
Term
What are examples of aminopenicillins? |
|
Definition
|
|
Term
What are antipseudomonal (extended spectrum) penicillins? |
|
Definition
|
|
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
|
|
Term
Where are penicillins ionized? |
|
Definition
|
|
Term
What is the Vd of penicillins? |
|
Definition
|
|
Term
How are penicillins excreted? |
|
Definition
|
|
Term
Which is more orally bioavailable - amoxicillin or ampicillin? |
|
Definition
|
|
Term
Are beta-lactams bacteriostatic or bactericidal? |
|
Definition
|
|
Term
What is the efficacy of beta-lactams linked to? |
|
Definition
Time the serum concentration remains above the MIC of the pathogen |
|
|
Term
|
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
|
|
Term
What is the main adverse effect of IV K pen G in horses? |
|
Definition
|
|
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
|
|
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
|
|
Term
What are the physiochemical properties of cephalosporins? |
|
Definition
Water soluble Poorly lipid soluble |
|
|
Term
What is the mechanism of action of cephalosporin? |
|
Definition
|
|
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
|
|
Term
What bacteria have shown resistance to carbapenems? |
|
Definition
Pseudomonas Enterococcus faecium MRSA |
|
|
Term
What are the routes of administration for carbapenems? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
Term
How are fluoroquinolones excreted? |
|
Definition
|
|
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
|
|
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
|
|
Term
Which nitroimidazoles can you use in food animals? |
|
Definition
|
|
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
|
|
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
|
Definition
|
|
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
|
|
Term
How is daptomycin administered? |
|
Definition
|
|
Term
What are the examples of glycopeptides? |
|
Definition
|
|
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
|
|
Term
How well is vancomycin absorbed? |
|
Definition
|
|
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
|
|
Term
What is linezolid primarily used for? |
|
Definition
|
|
Term
How bioavailable is linezolid? |
|
Definition
|
|
Term
What are examples of the streptogramins? |
|
Definition
|
|
Term
How orally bioavailable are streptogramins? |
|
Definition
|
|
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
|
|
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
|
|
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
|
|
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
|
|
Term
What are the food animal concerns of carbadox? |
|
Definition
Banned in Canada and the EU Carcinogen |
|
|
Term
What are examples of rifamycins? |
|
Definition
|
|
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
|
|