W13 Kidneys + Drug Therapy

Question 1

what is a nephrotoxic drug

Answer 1

drugs that have the potential to harm the kidneys

Question 2

what is important if a drug is classed as being nephrotoxic

Answer 2

understand the pharmacokinetics and pharmacodynamics of the prescribed medications

understand the clinical context of the patient and have the ability to interpret the available literature

Question 3

what options do we have when reviewing medications for Acute kidney injury or Chronic kidney disease

Answer 3

Stop drug

withhold drug

amend dose

continue

Question 4

what questions should we ask to ourselves if a patient has reduced renal function

Answer 4

is the patient in AKI or CKD

is the patient at risk of AKI

which medication should be suspended

which medication should be used with caution

are there any alternative option

what does should a medicine be reduced to

what additional monitoring do we need to do

what are the pharmacokinetics of the drug

what are the pharmacodynamics of the drug

Question 5

what issues with absorption (A) can a patient with reduced renal function have

Answer 5

patients typically have oedema as their kidneys are less efficient at removing water and salt. this can affect the wall of the bowel leading to reduced absorption of drugs

Question 6

what issues with distribution (D) can a patient with reduced renal function have

Answer 6

drug distribution is affected by water balance as oedema can affect drugs that are more hydrophillic.

Nephrotic syndrome leads to decreased protein levels in the blood. Many drugs are bound to proteins when in the blood. Lack of proteins will mean higher levels of free drug in blood. leading to toxicity

Question 7

what issues with metabolism (M) can a patient with reduced renal function have

Answer 7

Kidney failure means that these drugs will no longer be metabolised by the kidneys

uraemia can also reduce liver function leading to decreased metabolism of drugs

Question 8

what issues with excretion (E) can a patient with reduced renal function have

Answer 8

Reduced renal clearance means increased levels of drugs or their metabolites in the blood

Question 9

What does the acronym canada stand for

Answer 9

Contrast media
Ace Inhibitors
NSAIDs
Diuretics
ARBs

Question 10

what does NSAIDs stand for

Answer 10

Non-steroidal anti-inflammatory drugs

Question 11

what are ace inhibitors used to treat

Answer 11

hypertension, heart failure, nephropathy

Question 12

what do ace inhibitors work on

Answer 12

Renin angiotensin aldersterone system as it inhibits the conversion of angiotensin 1 to angiotensin 2

Question 13

what do we do with ace inhibitors when a patient has renal failure

Answer 13

hold

Question 14

what do we do with NSAIDs when a patient has renal failure

Answer 14

hold

Question 15

what do selective cox 2 inhibitors do

Answer 15

they inhibit prostaglandins which inhbits vasodilation of afferent arteriole leading to reduced kidney perfusion

they also promote sodium retention and therefor fluid retention

Question 16

what do diuretics cause

Answer 16

diuresis

Question 17

what is the purpose of taking a diuretic

Answer 17

increase NaCl exretion and hence water exretion

Question 18

what are the 5 different classes of diuretics (PLATO)

Answer 18

Potassium sparing diuretics

Loop diuretics

Aldosterone antagonists

Thiazide or thiazide like diuretics

Osmotic Diuretics

Question 19

what is the most powerful diuretic

Answer 19

loop

Question 20

what can loop diuretics be indicated for

Answer 20

Acute pulmonary oedema

Congestive heart failure

Fluid overload in renal/liver disease

Hypertension

Question 21

when should loop diuretics be given

Answer 21

they should not be offered in renal impairment unless managining oedema or when renal function is recovering or patient is awaiting renal replacement therapy

Question 22

what do loop diuretics act on

Answer 22

ascending limb of the loop of Henle

Question 23

how do loop diuretics work

Answer 23

they inhibit Na+ reabsorption meaning less water uptake and increased urine production

they also inhibit K+ and CL- reabsorption

they also inhibit urate excretion

Question 24

what are the adverse effects of a loop diuretics

Answer 24

Cause water excretion leading to dehydration which could lead to hypotension

Inhibit Na reabsorption = hyponatraemia

Inhibit K reabsorption = hypokalaemia

Inhibit Ca2+ reabsorption = hypocalcaemia

Inhibit Mg2+ re-absorption = hypomagnesia

Inhibit urate excretion can lead to hout

Question 25

what do thiazide and thiazide like diuretics act on

Answer 25

distal convoluted tubule of the nephron

Question 26

what is a thiazide like diuretic indicated for

Answer 26

oedema of cardiac renal or hepatic origin

hypertension: monotherapy or as an adjunct

Question 27

what do thiazide like diuretic do

Answer 27

Inhibit Na+ reabsorption = increases water excretion
Inhibit Cl- reabsorption
Inhibit K+ and Mg re-absorption

Increase Ca2+ absorption into the body

Question 28

what are adverse effects of thiazide like diuretics

Answer 28

hypokalaemia, 
hyponatraemia, 
hyperuricaemia 
hypercalcaemia,
hyperglycaemia
vasodilation (could be used as a positive)

Question 29

what do aldosterone antagonists do

Answer 29

increases water and sodium re absorption in the collecting tubule

inhibitng alodsterone means that less water and Na will be reabsorbed but increases reabsorption of K+ so known as potassium sparing

Question 30

what are other problem drugs

Answer 30

analgesics
antibioitcs
antieplieptics
anticholinergics
antispasmodics
antihypertensives
digoxin
hypoglycaemic agnets
Lipid lowering agents

Question 31

what is a sick day rule

Answer 31

temporarily discontinue taking certain drugs during acute interuccrent illnesses.