V. amstel Flashcards
1
Q
What effect of oxytetracycline in the blood may make it go down?
A
- Binding ionized calcium
2
Q
in a time dependent antibiotic what needs to be done to increase the dose interval?
A
- Increase the dose to extend the time
3
Q
Name on of the mechanism of bacteria resistance to oxytetracycline
A
- Slime formation and formation of the efflux pump
4
Q
Define the extended spectrum of oxytetracycline
A
- Mycoplasma, rickettsia, erlichia, protozoa and Babesia
5
Q
- What is the mechanism of action of oxytetracycline?
A
- Reversible 305 ribosome binding, relates to relapses as it’s a time dependent antibiotic
6
Q
- Oxytetracycline is not labeled to be used in lactating cows but it is used topically for foot warts- why?
A
- Topical use does not cause violative milk /tissue levels
7
Q
- Name a non antibacterial effect of tetracycline
A
Inhibit MMP
8
Q
- Under which circumstances would you have to use ampicillin rather than ceftiofur?
A
- Lactating dairy cow and veal calf
9
Q
- From an antimicrobial perspective give 2 reasons why cephalosporin might give a better clinical response than ampicillin?
A
- Wider gram negative spectrum, more beta lactamase release
10
Q
- What part of the cephalosporin ELDU cannot be violate?
A
- Dose route and frequency
11
Q
- What is the indication for long acting ceftiofur?
A
- Metaphylasis , tx of footrot metritis, BRD
12
Q
- For what type of antibiotic treatment is potassium penicillin often used?
A
- Regional iv ab
13
Q
- Why is the meat withdrawal time for procaine penicillin problematic?
A
- Because of the variation in dose rates affect it
14
Q
- Give 2 advantages of using synthethic penicillin over procaine penicillin?
A
- Gram negative spectrum/ can be used in lactating dairy cows and veal calves
15
Q
You have 2 ab , one has a vd 10 l/kg and the other 36 l/kg. which of the 2 ab would you choose for a case of septic meningitis? Assume that the sensitivity of both for the infection is the same.
A
- Vd 10 l/kg bactericidal
16
Q
- You have an animal with a lymph adenopathy. There are phagocytosed bacteria in the lymphocytes. Culture shows susceptibility to both penicillin and tulatromycin (macrolide). Which of the 2 antibiotics would you choose as a initial tx?
A
- Penicillin- bactericidal prefered over intracellular
17
Q
- In which production animal is the use of penicillin prohibited?
A
- Lactating cows and veal valves
18
Q
- Why is penicillin commonly used for the following wound infections, black leg and listeria?
A
Gram positive
19
Q
- What is the spectrum of penicillin?
A
- Gram positive anaerobe
20
Q
- AUC of penicillin would be affected if which organ fails?
A
- Renal
21
Q
- What does organophosphates have on the heart?
A
- Causes bradycardia
22
Q
- What is the toxic principle in fox glove causing arrhythmia?
A
- Digitalis
23
Q
- Name an anti- arrhythmogenic drug?
A
- Lidocaine
24
Q
- What is dx on clinical examination for a cow with septic pericarditis?
A
- Washing machine sounds
25
Q
- What is the normal rate in cattle?
A
- 50-80
26
Q
- What is a predisposing cause of atrial fibrillation in cattle?
A
- Displaced abomasum
27
Q
- Name 2 characteristics ECG changes associated with hyperkalemia?
A
- Dropped p wave, wider t complex
28
Q
- What lesion can black leg cause in the heart?
A
- Necrotizing myocarditis
29
Q
- What deficiency in young rapid growing sheep can cause acute death?
A
- Vit e /selenium
30
Q
- . What is the mechanism in high altitude disease?
A
- Chronic alveolar hypoxia
31
Q
- What is the blood electrolyte profile like in the ruptured bladder?
A
- Hyponatremia, hypochloremia, hyperkalemia
32
Q
- Why does the heart sound softly in hypocalcemia in fresh cows?
A
- Decrease in contractility
33
Q
- What would you do to a lower blood potassium level?
A
- Dextrose and insulin
34
Q
- Name one blood test which may alert you s to the presence of a low grade bacteremia?
A
- Hyperglobinemia
35
Q
- What symptoms should alert you as to the presence of a bacteremia?
A
- Hypopyon – fibrin in the eye, lameness- synovitis
36
Q
- What is the mechanism of the positive pole test?
A
- Fibrin attachment close to the peritoneum activate nociceptors
37
Q
- Which bacteria is most commonly associated with valvular endocarditis?
A
- T. PYOGENES
38
Q
- Which organ shows most edema with endotoxin?
A
lungs
39
Q
- How does endotoxin cause edema?
A
- Vasculitis increases capillary permeability- leakage
40
Q
- What is the most common cause of a murmur in calves?
A
- Ventricular septal defect
41
Q
- Which heart sound (systolic/diastolic) may be split in the bovine?
A
- Systolic- asynchronous closure because the left heart contract more strongly than the right heart
42
Q
- Give one ddx for CHF in the bovine?
A
- Valvular endocarditis
43
Q
- What is the origin of the normal/physiological jugular pulse?
A
- Mitral valve closing
44
Q
- What is the characteristic of the jugular vein with cardiac tamponade apart from distention?
A
- Not pulsation, the pressure on the heart causes to backload**
45
Q
- What is the mechanism of edema formation in cardiac tamponade?
A
- Hydrostatic pressures
46
Q
- Which group of antibiotics generally have a larger volume of distribution?
A
lipid soluble
47
Q
- Define volume of distribution:
A
total dose – bioavailability – blood concentration.
Inject 100mg absorbed 60%. Total amount in body 60 mg
blood concentration 20mg 60/20= 3L/kg
48
Q
- Name 3 factors that will influence bioavailability
A
- Dose/injection site and volume
49
Q
- Define bioavailability
A
- Amount of drug in blood measured by AUC
50
Q
- How can the amount of free antibiotic in the blood be increased ?
A
- Increased the dose
51
Q
- Name 1 factor which will influence the volume of distribution of an antibiotic
A
- Protein binding/charge/size/pH
52
Q
- Explain the mechanism of time dependent antibiotics
A
- Time above the MIC 40-70%
53
Q
- What is the half life of a drug?
A
- Time to half the concentration
54
Q
- Define AUD
A
- Amount of absorbed drug in blood stream
55
Q
- How does polar antibiotics (water soluble) cross the cell membrane?
A
- Active. receptor assisted
56
Q
- Name one factor that may increase the necessity of antibiotic use during surgical procedures?
A
- Tissue handling
57
Q
- For how long should antibiotic therapy be continued after the clinical symptoms disappear?
A
- 2 days
58
Q
- Explain antibiotic combination antagonism?
A
- Bacteriostatic and bactericidal
59
Q
- What is one of the best treatment approaches on finding an increase in fibrinogen, white cell count and presence on phagocytosed bacteria on microscopy?
A
- Combination showing synergism/ appropriate broad spectrum
60
Q
- Saving commensal and overall population susceptibility (bacterial refugia) is achieved by what treatment approach?
A
- Specific