Pharmacotherapy in Chronic Kidney Disease

Question 1

Effects of Renal Impairment due to drugs

Answer 1

● May see a decrease in renal metabolism of the drug.
● May see accumulation of drugs that are
normally excreted.
● Change in drug distribution – protein
binding.
● Accumulation of active metabolites

Question 2

Two most common causes of kidney disease

Answer 2

Diabetes and Hypertension

Question 3

Other causes of kidney disease:

Answer 3

■ Poisons, illicit drugs, medications, and herbal meds
■ Trauma
■ Age
■ Glomerular disease
■ Inherited and Congenital Kidney disease:
■ Polycystic Kidney Disease (PKD)

Question 4

Chronic Kidney Disease defined

Answer 4

The presence of kidney damage or a reduction in the glomerular filtration rate (GFR) for 3 months or longer

Question 5

Symptoms of CKD

Answer 5

○ Metabolic acidosis- ↓ body mass, muscle weakness, etc.
○ Alteration in water and sodium homeostasis- Peripheral edema, pulmonary edema (shortness of breath), hypertension.
○ Anemia- Fatigue, feeling cold.
○ Other- ↑ or ↓ Urinary frequency; foamy, bubbly, or bloody urine; difficulty urinating; rash or pruritus

Question 6

What tests help you determine
the degree of CKD?

Answer 6

○ Glomerular Filtration Rate
○ Serum Creatinine
○ Creatinine Clearance

Question 7

Glomerular Filtration Rate (GFR) tests for what?

Answer 7

An estimate of how much blood (volume) passes through the glomeruli each minute.

Question 8

Normal values for GFR

Answer 8

○ > 90 is normal
○ Most healthy adults have a GFR of about
130-140

Question 9

_____- Waste product of normal muscle metabolism

Answer 9

Creatinine (Cr)

Question 10

Serum creatinine

Answer 10

A measurement of creatinine in the blood

Question 11

Creatinine Clearance (CrCl or C Cr ) is a measure of what?

Answer 11

Rate at which kidneys remove
creatinine from the blood per minute

Question 12

Normal Creatinine levels

Answer 12

○ Women: 0.6-1.1
○ Men: 0.7-1.3

Question 13

Normal Creatinine clearance (CrCl)

Answer 13

○ Women: 88-128
○ Men: 97-137

Question 14

Things to consider with CKD

Answer 14

● Know level of renal (dys)function (GFR or Creatinine Clearance)
● Know the state of the liver (LFTs)
● Establish a loading dose, plan for maintenance dosing, check drug interactions, and monitor levels if needed

Question 15

The consensus of the literature is that many medications ____ require a change in the loading dose.

Answer 15

do not

Question 16

Loading doses may be required if a drug has a long _____

Answer 16

half-life and there is a need to rapidly achieve the desired steady state concentrations

Question 17

Methods for maintenance dosing adjustments

Answer 17

■ Dose Reduction: Reducing each dose while maintaining the normal dosing interval.
■ Lengthening the Dosing Intervals: Normal doses are maintained but the dosing interval is lengthened to allow time for drug elimination before re-dosing

Question 18

dosing adjustment vs. dosing interval risks

Answer 18

Dosing adjustment: Higher risk of toxicity
Dosing interval:
● Lower risk of toxicity.
● Risk of subtherapeutic levels

Question 19

Therapeutic Drug Monitoring

Answer 19

○ Blood draw to check serum concentration of the drug.
○ Allows for optimization of therapeutic treatments while
accounting for variations between individuals.
○ Requires rapid, specific, and reliable assays

Question 20

Drug classes to be aware of in CKD

Answer 20

○ Antihypertensive agents
○ Diabetes agents
○ Antimicrobials
○ Analgesics
○ Herbals

Question 21

Diuretics in CKD

Answer 21

○ Thiazides- Not recommended when
Creatinine clearance is <30 ml per minute.
○ Loops- Most common to treat uncomplicated HTN in patients with chronic kidney disease.
○ K+ sparing- Avoid, they can increase K+ which can be already elevated in CKD

Question 22

ACE inhibitors & ARBs in CKD

Answer 22

.■ Reduces HTN and proteinuria, slows progression of CKD.
Caution: Can cause acute decrease in GFR in the first few weeks of therapy (Monitor serum creatinine)
Titrate dose: Monitor weekly and titrate dose as needed until renal function returns to baseline

Question 23

Renal Elimination beta blockers (Adjustment Needed)

Answer 23

Atenolol
Bisoprolol
Nadolol
Acebutolol

Question 24

Hepatic Elimination beta blockers (No adjust needed)

Answer 24

Metoprolol
Propranolol
Labetolol

Question 25

Other antihypertensive medications that do not require adjustment in CKD patients

Answer 25

○ Calcium channel blockers
○ Clonidine
○ Alpha Blockers

Question 26

Metformin is _____% excreted renally

Answer 26

90-100

Question 27

Metformin is not recommended for CKD patients with

Answer 27

■ Serum creatinine > 1.5 in men and > 1.4 in women
■ GFR < 45 (contraindicated in GFR < 30)
■ Patients over 80 years of age
■ Patients with chronic heart failure

Question 28

If a Sulfonylurea is necessary, _____ is considered the safest of the three

Answer 28

Glipizide
(Chlorpropamide and glyburide should be avoided in advancing chronic kidney disease)

Question 29

Tetracyclines have an antianabolic effect and can worsen uremic state (urea builds up in the blood) but _____ does not cause the worsening uremic state

Answer 29

Doxycycline

Question 30

Vancomycin and Amphotericin can both cause _____

Answer 30

significant acute renal failure in healthy
kidneys, so should be avoided in CKD as well

Question 31

_____ has a toxic metabolite that can accumulate and cause peripheral neuritis

Answer 31

Nitrofurantoin

Question 32

T/F Aminoglycosides should be avoided if possible

Answer 32

T

Question 33

T/F Acetaminophen (Tylenol) can be safely used in patients with renal impairment

Answer 33

T

Question 34

Meperidine (Demerol), Morphine, Tramadol, & Codeine (Analgesics) with CKD

Answer 34

○ Metabolites can accumulate and cause CNS and respiratory adverse effects.
○ Not recommended in stage 4 or 5 CKD

Question 35

____% reduction in dose of morphine and codeine is recommended for patients with creatinine clearance less than 50 mL/minute

Answer 35

50

Question 36

Risks of NSAIDS with CKD

Answer 36

● Risk of acute renal failure is 3 times higher in NSAID users than non-NSAID users
● NSAIDs can blunt the effect of antihypertensive medications,
especially ACE inhibitors and ARBs

Question 37

____ and ____ accelerate the metabolism of some drugs and can perpetuate a buildup of metabolites

Answer 37

St. John’s Wort; Ginkgo