Met 2: Nephro; Lec. 14 Drugs And The Kidney

Front 1

What are the three factors determing GFR?

Back 1

Renal blood flow, (2 factors: effective circulating volume, and cardiac output)
Resistance to flow (i.e. vascular tone across afferent and efferent arterioles)
Permeability of glomerular basement membrane.

Front 2

What endogenous substances enhance the GFR through affecting the vascular tone? (one for efferent arteriole, one for afferent)

Back 2

Prostaglandins cause vasodilation, preferentially dilating the afferent arterioles.

Angiotensin causes vasoconstriction, preferentially constricting the efferent arterioles.

Both these actions increase GFR.
(Also affected by Norepinephrine , ANP, and dopamine)

Front 3

What four factors do you need to know to calculate a patient's creatinine clearance?

Back 3

Age,   
Mass (don't do any adjustments to estimate lean body mass),
Serum creatinine,
Gender.

Front 4

Calculate the creatinine clearance for these two patients with a serum creatinine of 100 umol/L:
40 y.o. 80 kg male, and
60 y.o. 50 kg female.

Back 4

Use Cockcrof-Gault:
CrCl = (140-age)(mass)/sCr  (*1.2 for males)

For the male:
CrCl = (140-40)(80)(1.2)/100 = 96 ml/min

For the female:
CrCl = (140-60)(50)/100 = 40 ml/min

Front 5

What are the three general ways that drugs can damage the kidney?  

(hint, same as the general causes of any kidney damage)

Back 5

Pre-renal
renal, and
Post renal

Front 6

What are the two most common etiologies of intrinsic renal damage caused by drugs?

Back 6

Acute tubular necrosis (ATN),
Allergic interstitial nephritis (AIN).

Front 7

What five types of drugs are most implicated in causing Acute Tubular Necrosis (ATN).

Back 7

Antibiotics (particularly aminoglycosides [gentamicin]) 
Immunosuppressants (cyclosporine, tacrolimus)
Radiocontrast dyes 
Statins (inducing rhabdomyolysis)
Chemotherapy agents (Cisplatin, and other platinum-based agents)

Front 8

What three types of patients are more at risk for kidney injury from radiocontrast dyes?

Back 8

Patients with:
1) Diabetes Mellitus, 
2) Chronic Renal Insufficiency (CRI), 
3) Previous Acute Kidney Injury (AKI).

Front 9

What three things can you do to minimize the risk from the test for patients with increased risk for kindey injury?

Back 9

use nonionic form
use the minimum amount
find an alternate test

Front 10

What should you do with their medications?

Back 10

HOLD
NSAID and ACEi or ARB

Front 11

What four measures should you take in treating a patient with nephrotoxic Acute Tubular Necrosis (ATN)?

Back 11

Stop causative nephrotoxic agent(s).
Avoid further kidney insults,
Monitor levels and renal function: adjust drug dosages based on renal function.
Apply appropriate supportive measures (i.e. dialysis if necessary)

Front 12

Name four classes of drugs that can cause allergic interstitial nephritis (AIN).

Back 12

Beta-lactams (cephalosporins & penicillins)
Sulfonamides,
Quinolones (ciprofloxacin, levofloxacin),
NSAIDS (ibuprofen),
Diuretics,
Proton Pump Inhibitors (omeprazole)
Anticonvulsants (phenytoin, carbamazepine)
Allopurinol

Front 13

How would you treat someone having a bout of AIN?

Back 13

supportive treatment
stop offending drug
avoid others within its class

Front 14

NSAIDs have multiple harmful effects on kidneys (both prerenal and renal).
What are the three sites at which that they directly damage renal function?

Back 14

Glomerulus: can cause a) Minimal Change Disease, b) Membranous glomerulopathy, and c) Analgesic nephropathy.
Interstitium: causes Allergic Interstitial Nephritis.
Tubules: causes hyperkalemia (by decreasing renin production and GFR)

Front 15

What electrolyte imbalance can result from ACEi and ARB usage?  Which drug has the greater effect?

Back 15

They can both cause hyperkalemia, due to decreased effect of aldosterone.  

ACEi seem to have the greater effect.

Front 16

What renal insult can be caused by long-term use of pain medications?

Back 16

Analgesic Nephropathy.

Front 17

What drugs are specifically implicated in analgesic nephropathy?

Back 17

antipyretics (NSAID, phenacetin, acetaminophen)
codeine

daily use over years

Front 18

What are four nephrotoxic effects of chronic lithium usage?

Back 18

Glomerular damage (Minimal change disease (MCD) and focal segmental glomerulosclerosis(FSGS))
Nephrogenic Diabetes Insipidus (DI) (from Li accumulation in the collecting tubules)
Tubular damage (renal tubular acidosis)
Interstitial damage (chronic interstitial nephritis)

Front 19

What are the two indications for diuretic therapy?

Back 19

Hypertension
Edema / volume overload (from CHF, cirrhosis, nephrotic syndrome)

Front 20

What are the three classes of natriuretic diuretics and their sites of action?

Back 20

Loop diuretics (Loop of Henle)
Thiazides diuretics (Distal tubule)
K-sparing diuretics (Collecting Tubule)

Front 21

Give an example of a loop diuretic.

Back 21

Furosemide,
Bumetanide,
Ethacrynic acid

Front 22

Give an example of a thiazide diuretic.

Back 22

Hydrochlorothiazide,
Metolazone,
Indapamide,
Chlorthalidone

Front 23

Give an example of a potassium-sparing diuretic.

Back 23

Amiloride,
Triamterine,
Spironolactone (note: has a different target than the other two)

Front 24

What types of electrolyte disturbances can patients develop while on diuretics? (give 3)

Back 24

Hypokalemia (except K-sparing),
Hypomagnesemia,
Hyponatremia,
Metabolic alkalosis,
Altered calciuresis (e.g. hypercalcuria -> stone formation)
hypercalcemia (thiazide)

Front 25

What are the four principals of renal dosing? (ADME)

Back 25

Absorption
Distribution
Metabolism
Elimination

Front 26

drugs that accumulate in renal failure

Back 26

benzodiazepines (most)
allopurinol
chlorpropamide
gentamicin
insulin
meperidine
morphine
gabapentin
glyburide
lithium
metformin