Pharmacotherapy in Chronic Kidney Disease Flashcards
Effects of Renal Impairment due to drugs
● 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
Two most common causes of kidney disease
Diabetes and Hypertension
Other causes of kidney disease:
■ Poisons, illicit drugs, medications, and herbal meds
■ Trauma
■ Age
■ Glomerular disease
■ Inherited and Congenital Kidney disease:
■ Polycystic Kidney Disease (PKD)
Chronic Kidney Disease defined
The presence of kidney damage or a reduction in the glomerular filtration rate (GFR) for 3 months or longer
Symptoms of CKD
○ 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
What tests help you determine
the degree of CKD?
○ Glomerular Filtration Rate
○ Serum Creatinine
○ Creatinine Clearance
Glomerular Filtration Rate (GFR) tests for what?
An estimate of how much blood (volume) passes through the glomeruli each minute.
Normal values for GFR
○ > 90 is normal
○ Most healthy adults have a GFR of about
130-140
_____- Waste product of normal muscle metabolism
Creatinine (Cr)
Serum creatinine
A measurement of creatinine in the blood
Creatinine Clearance (CrCl or C Cr ) is a measure of what?
Rate at which kidneys remove
creatinine from the blood per minute
Normal Creatinine levels
○ Women: 0.6-1.1
○ Men: 0.7-1.3
Normal Creatinine clearance (CrCl)
○ Women: 88-128
○ Men: 97-137
Things to consider with CKD
● 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
The consensus of the literature is that many medications ____ require a change in the loading dose.
do not
Loading doses may be required if a drug has a long _____
half-life and there is a need to rapidly achieve the desired steady state concentrations
Methods for maintenance dosing adjustments
■ 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
dosing adjustment vs. dosing interval risks
Dosing adjustment: Higher risk of toxicity
Dosing interval:
● Lower risk of toxicity.
● Risk of subtherapeutic levels
Therapeutic Drug Monitoring
○ 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
Drug classes to be aware of in CKD
○ Antihypertensive agents
○ Diabetes agents
○ Antimicrobials
○ Analgesics
○ Herbals
Diuretics in CKD
○ 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
ACE inhibitors & ARBs in CKD
.■ 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
Renal Elimination beta blockers (Adjustment Needed)
Atenolol
Bisoprolol
Nadolol
Acebutolol
Hepatic Elimination beta blockers (No adjust needed)
Metoprolol
Propranolol
Labetolol
Other antihypertensive medications that do not require adjustment in CKD patients
○ Calcium channel blockers
○ Clonidine
○ Alpha Blockers
Metformin is _____% excreted renally
90-100
Metformin is not recommended for CKD patients with
■ 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
If a Sulfonylurea is necessary, _____ is considered the safest of the three
Glipizide
(Chlorpropamide and glyburide should be avoided in advancing chronic kidney disease)
Tetracyclines have an antianabolic effect and can worsen uremic state (urea builds up in the blood) but _____ does not cause the worsening uremic state
Doxycycline
Vancomycin and Amphotericin can both cause _____
significant acute renal failure in healthy
kidneys, so should be avoided in CKD as well
_____ has a toxic metabolite that can accumulate and cause peripheral neuritis
Nitrofurantoin
T/F Aminoglycosides should be avoided if possible
T
T/F Acetaminophen (Tylenol) can be safely used in patients with renal impairment
T
Meperidine (Demerol), Morphine, Tramadol, & Codeine (Analgesics) with CKD
○ Metabolites can accumulate and cause CNS and respiratory adverse effects.
○ Not recommended in stage 4 or 5 CKD
____% reduction in dose of morphine and codeine is recommended for patients with creatinine clearance less than 50 mL/minute
50
Risks of NSAIDS with CKD
● 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
____ and ____ accelerate the metabolism of some drugs and can perpetuate a buildup of metabolites
St. John’s Wort; Ginkgo
