Pharmacology of the kidney

Question 1

what drugs are less effective in renal impairment ?

Answer 1

1) Thiazide diuretics

2) Nitrofurantoin ( antibiotics )

Question 2

what drugs have increased effect in renal impairments

Answer 2

1) Opioids

2) Sedatives

Question 3

What drugs have Increased Toxicity in renal impairments

Don’t Play Nights To Me

Answer 3

1) Digitoxin used for arrhythmias, nausea
2) Potassium sparring diuretics
3) Nitrofurantoin ( neuropathy)
4) Tetracyclines ( increased protein breakdown )
5) Metformin ( Lactic acidosis)

Question 4

Renal failure ( acute renal injury )
- What is it due to ?

Answer 4

60% of acute renal injury = pre renal = blood going to kidney is reduced this leads to decreased renal perfusion
due to :
1) Vomitting , diarrhoea
2) bleeding
3) cardiac failure
4) Cirrhosis
Loss of blood volume from systemic circulation leads to decreased renal perfusion

Question 5

Drugs associated with pre- renal Impairment

DANCR

Answer 5

Diuretics
Anti-hypertensives ( ACE inhibitors , ARBs)
NSAIDS
Cliclosporin (DMARD)
Radio contrast media

Question 6

Drugs that cause acute intrinsic kidney injury

Answer 6

1) Antiplatlets
2) Anti convulsants
3) DMARDS
4) Lithium
5) NSAIDS
6) COX inhibitors
7) Radio contrast media

Question 7

Acute kidney injury post renal impairment

Answer 7

1) Crystals + stones via methotrexate

2) Retroperitoneal fibrosis

Question 8

Which drugs should you completley stop in renal impairment ? Nephrotoxic drugs ?
what tests must you look at for detection ?

DAAMN

Answer 8

Diuretics
ACE inhibitors
Angiotensin receptor blockers
Metformin
NSAIDS

-serum creatine , eGFR, U&E

Question 9

Principles of prescribing in renal failure ?

5

Answer 9

1- most drugs = dose reduction is sufficient
2- reduce dose of drugs eliminated by kidney
3- time taken to reach the steady state increases
4-STOP the DAAMN drugs
5- Adjustment of maintenance dose should be made using GFR

Question 10

what are the main drug elimination rules

Answer 10

1) Half life is inversely proportional to creatine levels

2) 5X the half life is how long it takes to eliminate a drug !