Drug Choices and Therapeutics Flashcards
For each of the following clinical scenarios you must select an appropriate antibiotic (generic name and trade name). Dispense the correct amount and formulation and work out how much the drug will cost.
A 30 kg, 10 year old Male Doberman pinscher, the dog has a history of chronic renal failure but has recently been seen straining to urinate. Gram negative bacteria have grown on a laboratory culture (urine was collected by cystocentesis). White blood cells are also visible on urine sediment examination.
5mg/kg PO q24 for 14 days (incase of prostatic involvement)
Lecture says enrofloxacin first choice in entire males, also not nephrotoxic whereas other fluoroquinolones (gentamicin, nitrofurantoin) are.
Have attached this snip from the antibiotic book that seems quite useful!
Assuming we use enrofloxacin… (good vs gram -ve)
5mg/kg PO q24 for 14 days (incase of prostatic involvement)
5x30kg per day = 150mg
X14days = 2100mg.
Conveniently.. Baytril sell flavoured tablets at 150mg.
One Baytril per day for 14 days.
Fixed price = £5.27 + (14xvariable price)
Vp: £2.86 x 14
Cost = £45.31
Culture and sensitivity afterwards to confirm cured!
NB in the first q I assumed uncomplicated infection BUT if it is prostatis then must treat for 4-6 weeks rather than for 14d.
can just double the numbers to get 4wk worth or dose if you wanted to say it was prostatis
For each of the following clinical scenarios you must select an appropriate antibiotic (generic name and trade name). Dispense the correct amount and formulation and work out how much the drug will cost.
A 5 kg, 3 year old female Chihuahua that has presented with dysuria. The dog has no history of urinary tract infections, Urine sediment exam shows blood, white blood cells and gram positive cocci:
BSAVA recommends 12.5-25mg/kg q8-12h. 14d treatment according to lecture and safest idea.
Amoxicillin/clavulanate or tmps generally first choices. As gram + go for coamoxiclav
BSAVA recommends 12.5-25mg/kg q8-12h. 14d treatment according to lecture and safest idea.
25 x 5 = 125 x 2 = 250/day x 14 = 3500/ overall
Synulox 250mg: 5.27 + (14x0.82) (half a thing per day as sold in 250mg dose, so split into half in morning and half at night)
= £16.75
C and S after to ensure cure
For each of the following clinical scenarios you must select an appropriate antibiotic (generic name and trade name). Dispense the correct amount and formulation and work out how much the drug will cost.
What would you choose for case 2 if culture and sensitivity testing showed resistance to ampicillin and amocycillin/clavulanic acid:
A 5 kg, 3 year old female Chihuahua that has presented with dysuria. The dog has no history of urinary tract infections, Urine sediment exam shows blood, white blood cells and gram positive cocci:
Dose 15mg/kg PO q12 for 3d
Whatever came up as sensitive!
But for arguments sake go for TMPS.. or ciprofloxacin which is better vs gram + HOWEVER this only comes as eye drops with animals so may need human version which is more off-license? TMPS yolo
In humans they go for a 3d course according to lec, (or 7d ciprofloxacin)
TMPS - duphatrim
Dose 15mg/kg PO q12 for 3d
15x5 = 75mg/dose x 2/day = 150/d, x3 = 450mg.
Annoyingly tablets come as either 20mg or 80mg, so either overdose (probably not clever) or make up the right amount with scales and crushing tablet.
3 and ¾ 20mg tablets per dose, twice a day.
One tablet cost 0.2 +fixed fee of 5.27
Duphatrim is brand name
Sell 23 tablets then have 0.5 tablets left over.
23 x0.2 + 5.27 = £9.87
C and s after to confirm cure
Ciprofloxacin
Comes as eye drops so probably less useful or appropriate to dose.
•What products are available for supplementing K+ in cats and dogs? (4)
- Tumil-K (potassium gluconate) Powder/Tablet: delivers 2mEq of potassium gluconate in each tablet or ¼ of teaspoon.
- Injectable 20% KCl needs diluting 70x its volume with IV fluids (LRS).
- Kamminox is potassium gluconate + AAs + B vits and iron
- Cystopurin – potassium citrate – oral 30% solution. May be used to tx hypoK+ but potassium gluconate preferred
What clinical signs would you see in a hypokalaemic animal?
•Vomiting, lethargy, anorexia, weight loss, muscle pain, loss of muscle mass, generalised muscle weakness, paralysis if muscles involving resp – difficulty breathing. Cat = ventroflexion
How would you dose for hypokalaemia?
- How much to add to 250ml of 0.9% NaCL if potassium levels are…. <2mmol/l (20mmol), 2-2.5mmol/l (15mmol), 2.5-3 (10), 3-3.5 (7), 3.5-5 (5)
- Note: Drug interactions with ACEinhib or K+ sparing diuretics à causes life threatening hyperK+
At what serum level must you intervene to reduce potassium?
Why? What are the clinical signs of hyperkalaemia?
What would you see on an ECG trace?
•What therapeutic options are there for reducing its level or offsetting its clinical effects acutely in an emergency scenario?
- At what serum level must you intervene to reduce potassium? >7.5mEq/L as severe cardiotoxic effects occur between 8-11mEq/L (same as mmol/L). Defined as K+ >5.5mEq/L
- Why? What are the clinical signs of hyperkalaemia? Depression, weakness, lethargy, V+, D+ cardiac arrhythmias, straining to urinate ,comatose. Can occur in AKI (cant secrete)
- What would you see on an ECG trace? Bradydysrhythmias , small P waves or loss of P waves, wide QRS, narrow + tall T waves, AV block, short QT interval . VFIB L ventric standstill.
- What therapeutic options are there for reducing its level or offsetting its clinical effects acutely in an emergency scenario?
- IV admin 0.9% NaCl initially
- Sodium bicarbonate to correct acidosis (H+) – don’t use if also hypernatraemic
- 10% calcium gluconate – 20mg/kg IV slowly at 22ml/kg over 10-30mins – for cardioprotection. Onset immediate last 60mins.
- Insulin and dextrose may have a role – this drives K+ into cells. Onset 15mins lasts 4-6hours
- B2 adrenoagonists – albuterol/turbuteline – emergency approach onset 30mins, lasts 2hrs. Beware high HR. Increase Na+/k+ ATPase
- Diet is the most effective way of controlling increased phosphate in CRF patients
- If a cat will not eat the renal diets, what other options are there?
–Make it more tasty/warm/smelly – add fish– ideally it needs to eat it as P binders don’t work well on their own. Naso-oesophageal tube
–Maropitant (cerenia) – anti-emetic – NK1 rec antagonist – make them more likely to eat
–Phosphate binders – Aluminium hydroxide powder 150mg/kg/day, calcium carbonate (ipakitine – cats)
–Pronefra (combo of 2 P binders) Limits the bioavailablity of P, binds ureamic toxins, helps maintain normal kidney architecture, supports blood pressure. Cat 0.25ml/kg
–Sucralfate (aluminium hydroxide + sulfated sucrose) – mucosal protectant
•Identify some therapeutic options and calculate a management programme for a 4kg cat with hyperphosphatemia
–Diet (whatever it says on the packet) – renal care
–P binders - Ipakitine (ca carbonate) = 1g/5kg = 0.74g for cat
–If CKD = ACE Inhib, fluids, mild laxative if constipated
Would you use rocaltrol in renal patients? What are the complications?
Not really any more
Calcitriol – normally this hormone is a vit D metabolite and noramlly increases blood calcium levels by : pomoting absortpion from gut and increasing renal tubular reabsorption
Reasons FOR – sometimes works as lack of calcitriol can cause. Will inhibit PTH production so will in turn reduce Ca, stops renal hyperPTH occuring
Reasons AGAINST – only anecdotal evidence, can only use when P levels normal (unlikely in CKD), can cause hyperCa (calcification)
Not a first line tx, not a substitute for renal care diet or P binder
When might you use erythropoietin?
- In chronic kidney failure often get anaemia – EPO deficiency (blood loss, GI loss, urea inhibits erythropoesis, iron deficiency, reduced life span of RBCs).
- Need to monitor iron levels
- Darbepoetin – less risk with this than other older human EPO
- Dose: 1ug/kg SC weekly until PCV is normal then reduce dose gradually
- Human drug – be careful of autoantibodies
Not that commonly given, very expensive
Fortekor; benazepril hydrochloride
What is it, where and how is it used?
- ACE inhibitor – benazapril hydrocholride. Fortekor PLUS = + pimobendan (heart failure – pos inotrope and vasodilate)
- Licenced for tx of DCM or Mitral valve disease
- If CKD present then must check hydration status first and monitor creatinine and RBC count
- Action – stops conversion of ATI à ATII, so stops RAAS so causes vasodilation and salt/water excretion , reduce GFR + blood pressure
Amodip
What is it, where and how is it used?
- cat licenced for systemic hypertension. Cats 0.125-0.25mg/kg – can increase after 14d up to double dose
- Amlodipine Action – Ca channel blocker – stops Ca entry into muscle cells and bv relaxation, vasodilation, lowering BP.
- Note sometimes cause decrease in K+ and Cl-
•Make a treatment plan for a dog in acute renal failure due to NSAID intoxication
- Discontinue all nephrotoxic drugs. Consider measures to decrease absorption = emesis induction (apomorphine), activated charcoal
- Start antidote if there is one (not sure if one for NSAIDs)
- Identify and treat pre-renal or post renal issues à fluids
- Fluids à IV saline or 0.45% saline in 2% dextrose, rehydrate within 4-6hours (larger volume) , then maintenance 2ml/kg/hr and ongoing losses (urine, V+, D+)
- Correct acid base and electrolyte disturbances
- Maybe dialysis?
When might you use diuretics in acute renal failure?
- Azotemia risk is increased if give diuretics with NSAIDs
- Normally see GI signs with NSAID toxicosis
- Maybe give if after 24 hours if not corrected then worried about overloading – if still anuric last resort
