EIM 1-5 Flashcards
Innate immunity is ?
rapid, is nonspecific, results in acute inflammation, and has no memory
Adaptive immunity is?
takes time to develop, is antigen specific, and has recall capability
ENTEROHEPATIC CIRCULATION IS AN EXAMPLE OF :
A) an open model
B) a closed model
C) reduce reuse recycle
B) a closed model
WHICH COMPARTMENT IS RESPONSIBLE FOR ELIMINATION OF A DRUG?
A) central compartment
B) peripheral compartment
C) deep compartment
A
A) central compartment – highly perfused tissues, equilibrate rapidly – kidney and liver, where elimination occurs
B) peripheral compartment – less perfused, muscle and connective
C) deep compartment – slowly perfused, bone and fat
ZERO ORDER ELIMINATION OCCURS ONLY WHEN WHAT HAPPENS?
TWO EXAMPLES ARE?
-elimination mechanisms become saturated
-bile secretion and renal tubular secretion
LOW OR POOR ORAL BIOAVAILABILITY:
A) is a cause of subtherapeutic dosing of antibiotics
B) is a cause of anthelmentic resistance
C) can result in overdosing of some animals
all
WHAT DETERMINES HOW READILY A DRUG WILL CROSS BIOLOGIC MEMBRANES?
Degree of lipid solubility
Lipid soluble = nonpolar
Water soluble = polar
Highly lipophilic drugs diffuse easily across almost all tissue membranes.
Most of the drugs used in equine practice exist as weak acids or weak bases. Their lipid solubility depends a great deal on their degree of ionization (charged state).
An ionized drug is hydrophilic and poorly lipid soluble.
A nonionized drug is lipophilic and can cross biologic membranes.
ACIDIC DRUGS SUCH AS NSAIDS TEND TO BIND TO ___?
albumin
THE PRINCIPLE OF SUPERPOSITION :
A) says that early doses of a drug do not affect the pharmacokinetics of
subsequent doses
B) says a loading dose of a drug is necessary to ensure steady state
pharmacokinetics of subsequent doses
A
For most drugs, as equal doses are given at a constant dosage interval, the plasma concentration-time curve plateaus and a steady-state is reached. At steady-state the plasma drug concentration fluctuates between a maximum concentration (Cmax, or peak) and minimum concentration (Cmin, or trough). Once steady-state is reached, Cmax and Cmin are constant and remain unchanged from dose to dose
RENAL DISEASE CAN CAUSE ACCUMULATION OF:
A) proteins
B) electrolytes
C) drug metabolites
c)
WITH THE DOSE-REDUCTION METHOD THE NORMAL DOSAGE REGIMEN IS ADJUSTED BY REDUCING THE \_\_\_\_ AND MAINTAINING THE \_\_\_ ? A) interval; dose B) dose; interval C) concentration; dose D) dose; concentration
B
T/F?
It is easy to determine if a drug is bacteriocidal or static based on the MBC to MIC ratio
F: For many drugs the distinction between bactericidal and bacteriostatic is not exact and depends on the drug concentration attained in the target tissue and the pathogen involved. Specific situations in which a bactericidal drug is preferred over a bacteriostatic drug include immunocompromised patients such as neonates, life-threatening infections such as bacterial endocarditis and meningitis, and surgical prophylaxis.
CONTINUATION OF PROPHYLACTIC ANTIMICROBIALS FOR MORE THAN __ DAYS IS LIKELY UNNECESSARY AFTER COLIC SURGERY.
3
Beta-lactams: T/F
Distribute well into protected sites (CNS, eye, prostate)
F
Beta-lactams: T/F
Are time dependent, require frequent dosing
T
Beta-lactams: T/F
Can have significant side effects
F
Beta-lactams: T/F
Are highly bound to plasma proteins
F
Beta-lactams: T/F
Mostly hepatic/biliary excretion
F
Beta-lactams: T/F
Active against actively multiplying bacteria only
T
Beta-lactams: T/F
Gram negative bacteria have LPS layer, making penicillin easier to penetrate into bacterial cytoplasm
F
Beta-lactams: T/F
Don’t penetrate mammalian cells, therefore ineffective for intracellular pathogens
T
Majority of bacteroides fragilis isolates are resistant to B-lactams because of which resistance mechanism:
A: The presence of the chromosomal gene mecA
B: Decreased affinity of its ‘penicillin binding proteins’ (PBPs)
C: Production of beta-lactamase enzymes
D: Production of beta-lactamase inhibitors
C
Extended spectrum beta-lactamases (ESBLs) can hydrolyze 3rd and 4th gen. cephalosporins.
Which is true regarding their expression and clinical relevance?
Plasmid mediated expression via gene MecA, expressed by methicillin-resistant Staph.
Chromosomal mediated expression via gene MecA, expressed by methicillin-resistant Staph.
Plasmid mediated expression, which often encode for other genes that infer resistance other classes of antimicrobials i.e. multi-drug resistant bacteria like E. coli and Klebsiella
Chromosomal mediated expression, which often encode for other genes that infer resistance other classes of antimicrobials i.e. multi-drug resistant bacteria like E. coli and Klebsiella
C
Elimination of penicillin is primarily:
A: Renal – via glomerular filtration
B: Renal – via active renal tubular secretion
C: Renal – via glomerular filtration and active renal tubular secretion
D: Firstly altered in the liver, and then renally excreted
C
Because of its strong antipseudomonal activity, the following can be used for intrauterine administration to treat endometritis in mares: Ampicillin Amoxicillin Ticarcillin Benzylpenicillins
Ticarcillin
Which risk/disadvantage consideration with cephalosporin treatment is true?
A: Adverse effects include nephrotoxicity
B: May cause overgrowth (“superinfection”) by inherently resistant bacteria e.g. C. difficile, due to their broad spectrum activity
C: All generations are ineffective against Pseudomonas spp.
D: They are ineffective against Beta-lactamase producing Staph.
B
Cephalosporins
Cefazolin is 1st generation Ceftazidime is 3rd generation Ceftriaxone is 3rd generation Cefpodoxime is 3rd generation Cefquinome is 4th generation
Cephalosporins –
- Bioavailability low, except cepodoxime in foals
- Large volume of distribution, including intracellular penetration
- Eliminated unchanged in the urine
- All generations have good CSF penetration
- True
- False, it’s low Vd and therefore mainly to ECF only
- True
- False – just 3rd and 4th
T/F: Cephalosporins –
- Ceftiofur can be used for Strep. equi. zoo. endometritis, but is not effective for placentitis
- CCFA in neonatal foals had shorter Tmax and higher Cmax than in adults given CCFA
- Have low therapeutic index
- True
- True
- False
Cephalosporins are potentially nephrotoxic due to
immune complexes in the glomerular basement membrane
Ceftiofur CFA protocol in foals:
A: Same as dose as adults (6.6mg/kg), same route and same frequency
B: Different dose to adults (half – 3.3mg/kg), same route and frequency
C: Same dose as adults (6.6mg/kg), but SC and q72h for MIC <0.5ug/mL
D: Different dose to adults (half – 3.3mg/kg), but SC and q72h
Answer – c, note weanlings should be similar to adult protocol
Carbapenems (e.g. imipenem and meropenem) have extended spectrum because of:
A: withstand the beta-lactamases produced by some bacteria
B: ability to penetrate porin channels that usually exclude other drugs
C: activity against MRSA and Enterococcus faecium
D: A and B
Answer D, they DO NOT have activity against MRSA and Enterococcus faecium
Which abx have excellent activity against Pseudomonas aeruginosa?
Amikacin and tobramycin
Aminoglycosides are generally ineffective in abscess environments because:
They are inactivated by the nucleic acid of dying WBCs
- activity is decreased in acidic environments
- activity is decreased in anaerobic environments
—(actually have improved activity in alkaline env)
Neonatal foal aminoglycoside dosing differs to adults because:
Cmax is lower due to greater Vd (larger ECF vol), higher dose
increased elimination half life, longer dose interval
Aminoglycosides are transported into renal Proximal tubular epithelial cells via:
pinocytosis from tubule lumen across apical brush border
High dose once daily aminoglycoside dosing is advantageous because:
they have long post-antibiotic-effects (PAE), therefore longer dosing interval prevents first exposure adaptive resistance of bacteria
Decreased risk of nephrotoxicity
utilizes concentration dependent killing of bacteria
Which would be considered superior for identifying early AG nephrotoxicity
Increased urine GGT, or increased urine GGT : uCr ratio
In regards to pain, glutamate is…
The major excitatory neurotransmitter in the spine
THE MOST COMMONLY USED DRUGS IN HORSES ARE:
NSAIDs
How should the dose of epinephrine be adjusted when administered intratracheally?
double the volume
Disadvantages of plasma as a resuscitation fluid in horses
prolonged time for administration
relatively short duration of oncotic effect
potential for adverse reactions (10% incidence)
high cost if given for large-volume resuscitation
Hypertonic Saline
Hypertonic saline solution (HSS) is approximately 8 times the tonicity of plasma and ECF, and the immediate effect is to rapidly expand the vascular volume by redistribution of fluid from the interstitial and intracellular spaces. Initially, this is a roughly 1:3 ratio—that is, for every liter of HSS administered, the patient recruits up to 3 L of volume expansion.
The dose of hypertonic saline is 2 to 4 mL/kg, administered as quickly as possible.
WHAT IS THE ULTIMATE COLLOID REPLACEMENT FLUID?
Whole blood
- ideal fluid for blood loss or platelet loss
- fresh and has been cross-matched
may restore circulating volume, improve oncotic activity, increase oxygen-carrying capacity, is a supply vehicle for therapeutic drug transport, and replenishes coagulation factors.
Pulse Pressure
-the difference between systolic and diastolic pressure (SAP − DAP)
- A bounding pulse pressure results from an increased systolic pressure. or decreased diastolic pressure.
- A poor or weak pulse quality indicates little difference between SAP and DAP.
Ultimately, pulse pressure is not a good surrogate of perfusion, and clinical markers of perfusion or quantitative methods of CO are required for improved accuracy.
Indications for mechanical ventilation
A: marked hypoxemia (Pao2 < 60 mm Hg)
B: marked hypoventilation (pHa <7.3 with Paco2 >65 mm Hg)
C: lack of response to maximal pharmacologic ventilation
D: fatigue or excessive work of breathing
Delayed analysis of a blood sample for blood-gas-analysis results in
increased PaCO2
Increased lactate
decreased pH
decreased glucose
Because blood cells continue to metabolize nutrients
What is the ratio of PaO2 to FiO2 in a healthy normal standing horse ?
5:1
PAo2 is influenced by the fraction of inspired oxygen (Fio2), atmospheric pressure, and Paco2.
Pao2 is typically five times the Fio2 in the healthy standing horse
therefore, in a patient breathing room air at sea level (Fio2 = 21%), expected Pao2 concentration is approximately 100 mm Hg with an Sao2 >93%.
What is the approximate maintenance energy requirements for healthy adult horses
30-40 kcal / kg / d
What is the approximate maintenance energy requirements for critically ill foals
50 kcal / kg / d
Which hormones are reduced with non-selective NSAID use?
they promote vasodilation, perfusion, and health of the inner medulla
Prostaglandin E2 (PGE2) prostacyclin (PGI2)
It is advisable to monitor serum BUN and creatinine concentrations at what frequency in critically ill equids to assess glomerular filtration and renal function?
q48h
Which of the following indicates tubular damage:
A: granular casts in urine
B: increased urinary γ-glutamyl transferase-to-creatinine ratio (>25)
C: abnormal fractional clearance of electrolytes e.g. sodium and potassium
D: increased urinary glucose
ALL
Urinary indicators of tubular damage include granular casts in urine, an increased urinary γ-glutamyl transferase-to-creatinine ratio (>25), abnormal fractional clearance of electrolytes such as sodium and potassium, and increased urinary glucose.
Azotemia is likely pre-renal if the azotemia decreases by what percentage following 24 hours of fluid therapy?
> 50%
Azotemia that decreases by ≥50% in 24 hours in response to fluid therapy (usually at rates >80–100 mL/kg/day) indicates pre-renal azotemia
Urination should be expected within what period of time following furosemide admin.?
E.g. 1mg/kg IV
30 minutes
A blade of grass would store the most fructan on…
A cold, bright day
High rates of photosynthesis combined with low rates of growth result in high production of sucrose that gets stored as large amounts of fructan (along with starch makes up the majority of NSC’s)
Dietary risk factors for colic
Change in concentrate feeding
Change in turnout
Changes in type of hay fed
NOT Type of concentrate fed
To increase a horse 1 BCS in 60 (gain of 35kg) you should
add 6-7mCal/day
Minimum DMI for mature horses and ponies is
1.5% BW
max is 3.2%
average is 2.5%
Dilute urine (SG ≤1.012) concurrent with azotemia generally indicates
decreased renal function
Azotemia with isosthenuria (SG 1.008–1.012) indicates
renal failure
An example of first order elimination is
glomerular filtration
