Clinical pharmacology in renal disease

Question 1

Renal disease can cause drugs or their metabolites to accumulate in the body. When is this not particularly hamrful

Answer 1

When the drug has a high therapeutic index or low toxicity

When the metabolites have a low toxicity

Question 2

Outcomes of gentamicin, lithium and digoxin toxicity

Answer 2

Gentamicin - Renal or Ototoxicity
Lithium - Renal toxicity, Death
Digoxin - Arrhythmias, Nausea, Death

Question 3

3 methods of renal excretion

Answer 3

Glomerular filtration (main one)
Passive tubular reabsorption
Active tubular secretion

Question 4

Where are all drugs and their metabolites filtered

Answer 4

The glomerulus

Question 5

What should be done with a patient with reduced GFR when prescribing drugs

Answer 5

REDUCE DOSAGE
Increase dosage interval
Monitor blood levels for toxic drugs

Question 6

4 toxic drugs

Answer 6

Gentamicin
Vancomycin
Digoxin
Lithium

Question 7

What effect does renal disease have on the blood brain barrier

Answer 7

Makes it more permeable 》brain becomes more sensitive to sedatives, opiates and tranquillisers

Question 8

What can renal disease do to circulating volume and what caution should be taken

Answer 8

Can reduce circulating volume

Making patients very sensitive to antihypertensives (ACE-I or alpha-blockers)

Question 9

What can renal disease do in regards to bleeding and what cautions should be taken

Answer 9

Increase bleeding risk

Beware warfarin and NSAID’s

Question 10

How can renal disease alter pharmacokinetics

Answer 10

Increased half life
Build up of drug or metabolites
Decreased protein binding 》more free drug

Question 11

How can renal disease alter pharmacodynamics

Answer 11

Increased sensitivity to pharmacological action
Increased sensitivity to toxicity
Increased sensitivity to adverse drug reactions ADR’s

Question 12

What does TDM stand for

Answer 12

Therapeutic drug monitoring (test?)

Question 13

What should be considered when prescribing a drug to patient with renal impairment

Answer 13

Risk/benefit ratio
Severity of toxicity and SE
The availability of TDM
Can a different drug be used

Question 14

What drugs are ideal for patients with renal impairment

Answer 14

Drugs with a High therapeutic index

Drugs that are metabolised by the liver and have non-toxic metabolites

Question 15

Treatment for hypertension for those with renal impairment

What’s the problem with this treatment

Answer 15

ACE-I

Can be nephrotoxic

Question 16

Four major symptoms of Drug

Induced Renal Disease

Answer 16

Acute renal failure
Nephrotic syndrome
Renal tubular dysfunction with potassium wasting
Chronic renal failure

Question 17

3 types of acute renal failure

Answer 17

Pre-renal
Renal or Intrinsic
Post-renal or Obstructive

Question 18

What is nephrotic syndrome and give two drugs implicated in it

Answer 18

It’s glomerular dysfunction and marked by HEAVY proteinuria

NSAID’S and Interferon

Question 19

Why can NSAID’s cause renal failure

Answer 19

Decrease synthesis of renal dilators prostaglandins 》Reducing renal blood flow

Question 20

What happens to urea and creatinine in drug induced renal disease

Answer 20

Increase

Question 21

What happens to fluid and electrolytes in drug Induced renal disease

Answer 21

Fluid and electrolyte abnormalities

Question 22

When should you really avoid nephrotoxic drugs

Answer 22

Patients with renal impairment
Patients that are volume deficient or hypotensive
Patients already receiving nephrotoxic therapy