PSA

Question 1

ACEi/ARB in CKD

Answer 1

• Do not prescribe together in CKD, both can cause renal hypoperfusion
• Check potassium (U+Es) and eGFR before starting treatment and 1 - 2 weeks after
• If eGFR falls by 25% or more or serum creatinine rises by 30% or more - then stop

Question 2

How to treat hyperkalaemia

Answer 2

• 10ml 10% calcium carbonate in resus and 30ml 10% calcium gluconate for other patients (= 6.8mmol calcium)
• 10 units of insulin and 25g glucose IV
• Neublised salbutamol as adjuvant

Question 3

Fluid deficit + maintainence fluid in children

Answer 3

Fluid deficit (mL) = % dehydration x weight (kg) x 10

Maintenance fluids
100mL/kg/day for first 10kg
50mL/kg/day for next 10kg
20mL/kg/day for the rest

Question 4

Hyponatraemia (< 135mmol/L) causes

Answer 4

Hypovolaemic (FAD)

• Fluid loss/dehydration
• Addisons (reduced aldosterone, less Na reabsorbed in tubules)
  
  • Diuretics (prevent Na reabsorption)
  Euvolemic
  • SIADH
  • Medications
  • Endocrine disorders (secondary adrenal insufficiency)
  Hypervolemic
  • Fluid overload (renal/heart failure)

Mx: fluid restriction, demeclocycline/tolvaptan

Question 5

Medication causes of hyponatraemia

Answer 5

Some Drugs Act Against Kidneys

• SSRI
• Diuretics
• Anticonvonvulsants
• Antipsychotics
• Killing cells/Khemo
• Ramipril as well

Question 6

Causes of hypernatraemia

Answer 6

“4 Ds”

• Dehydration
• Drips - excess IV fluiuds (avoid NaCl as maintenance fluid, use Hartmann’s
• Drugs (diuretics if too much UO, steroids)
• Diabetes insipidus

Question 7

Hypokalaemia causes (DIRE) < 3.5

Answer 7

• D- drugs (loop diruetics - furosemide, thiazide, indapamide)
• I - inadequate intake/ intestine loss
• E - endocrine (Conn’s, Cushings)

Question 8

Hyperkalaemia causes (DREAD)

Answer 8

• Diuretics (K sparing, ACEi)
• Renal failure
• Endocrine (addisons)
• A- Artefacts (e.g. clotted sample, sample taken from IVI side)
• D - DKA

Question 9

Medication causes of hypokalaemia (K-WASTING)

Answer 9

• K - Korticosteroids
• Water pills (loop and thiazide)
• Antibiotics (Amphotericin B, high-dose penicillins
• Salbutamol
• Theophylline
• N - N/A
• G- GI losses (e.g. lax overuse)

Question 10

Hyperkalaemia medication causes (THANKS B)

Answer 10

• Trimethoprim
• Heparins
• ACE inhibitors and ARBs
• NSAIDs
• K-sparing diuretics
• Beta blockers (e.g. propranolol)

Question 11

CYP450 inhibitors (All My Owls Are Gorgeous)

CYP450 enzyme responsible for metabolising different drugs

Answer 11

Inhibitors decrease drug metabolism and increase potential for toxicity:

• Azoles: ketoconazole, fluconezole, miconazole (↑ warfarin conc.)
• Antibiotics: metronidazole, macrolides (erthyromycin, clarithromycin)
• Omeprazole (use lansoprazole when pt on clopidogrel)
• Amiodarone
• Grapefruit juice

SSRIs = CYP450 substrate (metabolised by CYP450), so grapefuit = bad

Atorvastatin (substrate) + macrolide = ↑muscle pain, weakness, tenderness +/- dark urine. Stop statin when on macrolide

Question 12

CYP450 inducers (Lily “Always Sleeps, Relaxes and Sploots)

Answer 12

Inducers increase CYP450 enzyme levels = increased metabolism of drugs and reduced therapeutic concentration

• Anticonvulsants: phenoytoin, carbamazepine
• Steroids: dexamethasone, prednisolone
• Rifampicin
• St John’s Wort, alcohol, nicotine

Reduces levonorgestrel and COCP effectiveness!