CKD

Ch. 18 Naplex 2025 book

What equations are commonly used to calculate GFR (eGFR)?

MDRD and CKD-EPI

What is albumin, and why is it measured in urine?

primary protein measured in urine to assess kidney disease.

What is another name for albuminuria?

Proteinuria.

According to KDIGO guidelines, what is used to evaluate the severity of renal impairment?

GFR, degree of albuminuria, and the cause of CKD.

What are the criteria for confirming CKD?

eGFR <60 mL/min/1.73 m² OR albuminuria (AER ≥30 mg/24 hr or UACR ≥30 mg/g)

must have either for longer than 3 months

How long must decreased eGFR or albuminuria be present to be considered CKD?

More than 3 months.

What are the GFR categories and CKD stages?

G1: ≥90 + kidney damage (Stage 1);

G2: 60–89 + kidney damage (Stage 2);

G3a: 45–59;

G3b: 30–44 (Stage 3);

G4: 15–29 (Stage 4);

G5: <15 or dialysis dependent (Stage 5).

What is the normal GFR in healthy kidneys?

Approximately 125 mL/min/1.73 m².

What are the albuminuria categories based on ACR or AER?

A1: <30 mg/g (or mg/24 hr);

A2: 30-300 mg/g (or mg/24 hr);

A3: >300 mg/g (or mg/24 hr).

What does A1 albuminuria represent?

Normal to mildly increased albuminuria (previously normoalbuminuria).

What does A2 albuminuria represent?

Moderately increased albuminuria (previously microalbuminuria).

What does A3 albuminuria represent?

Severely increased albuminuria (previously macroalbuminuria).

What is the KDIGO blood pressure goal for patients with CKD and hypertension?

SBP <120 mmHg if tolerated.

What is the first-line treatment for CKD with hypertension?

An ACE inhibitor or ARB.

(REMEMBER THESE ARE CI IF USED TOGETHER DUE TO RISK OF HYPERKALEMIA)

How do ACE inhibitors and ARBs work to delay the progression of CKD?

They cause efferent arteriolar dilation, reduce glom pressure, and decrease albuminuria

What can be expected after starting a ACEi or ARB in pts with HTN and CKD? and is this a reason to d/c therapy?

Up to a 30% increase in Scr

NO dont stop therapy!

Should an ACE inhibitor or ARB be stopped if SCr increases by ≤30% after initiation? if not, when would they be stopped?

No, this increase is expected.

d/c if the increase if >30%

What supplements should patients avoid while taking an ACE inhibitor or ARB?

Potassium supplements and potassium-containing salt substitutes.

What should be monitored 2-4 weeks after starting an ACE inhibitor or ARB?

Blood pressure, serum creatinine (SCr), and potassium.

What is the KDIGO-recommended first-line treatment for diabetes in patients with CKD? and what is the criteria they must meet to take it?

An SGLT2 inhibitor (farxiga, jardiance, invokana)

eGFR > /= 20

What is recommended if a patient with CKD + DM cannot use an SGLT2 inhibitor or needs additional glycemic control?

A GLP-1 receptor agonist (ozempic, victoza, trulicity)

What is finerenone? and what are the benefits of it in CKD

A nonsteroidal mineralocorticoid receptor antagonist.

It reduces CKD progression and cardiovascular risk.

When can finerenone be added to therapy in CKD?

In patients receiving an SGLT2 inhibitor and a maximally tolerated ACE inhibitor or ARB who have eGFR ≥25, albuminuria, and normal potassium levels.

How may dosing change for drugs eliminated through the kidneys in CKD?

The dose may be reduced and/or the dosing interval may be extended.

Why are dose reductions or interval extensions used in CKD?

To avoid drug accumulation and toxicity.

Name two drugs that become less effective as kidney function declines.

Thiazide diuretics and nitrofurantoin.

Give an example of a side effect that may become more significant in CKD.

Hyperkalemia with aldosterone receptor antagonists (spironolcatone)

Which anti-infective drugs commonly require dose reduction or interval extension in CKD?

Aminoglycosides, beta-lactam antibiotics, fluconazole, quinolones (except moxifloxacin), vancomycin

Which cardiovascular drugs commonly require dose adjustment in CKD?

Enoxaparin, rivaroxaban, apixaban, dabigatran

Which other common drugs require dose adjustment in CKD?

Famotidine, metoclopramide, bisphosphonates, lithium

At what CrCl should medication dose adjustments generally be considered?

CrCl ≤60 mL/min.

At what CrCl may additional dosage adjustments be needed or drugs become contraindicated?

CrCl ≤30 mL/min.

What CrCl represents normal renal function in a young adult?

CrCl 120-125 mL/min.

Which drugs are contraindicated when CrCl <60 mL/min?

Nitrofurantoin

Which drugs are contraindicated when CrCl <50 mL/min?

Tenofovir disoproxil fumarate (TDF)-containing products and IV voriconazole.

Which drugs are contraindicated when CrCl <30 mL/min?

Tenofovir alafenamide (TAF)-containing products, NSAIDs, and dabigatran (for DVT/PE).

When is metformin contraindicated in pts with CKD?

eGFR <30 mL/min/1.73 m² (for pts who have been on it)

eGFR < /=45 (do not initiate in these pts)

What is CKD-MBD?

CKD mineral and bone disorder, a complication of renal impairment that is common in dialysis patients.

What complications are associated with CKD-MBD?

Fractures, cardiovascular disease, and increased mortality.

What laboratory values should be monitored in advanced CKD?

Parathyroid hormone (PTH), phosphorus (phosphate, PO4), Ca, and vitamin D.

How does hyperphosphatemia affect PTH levels?

It causes chronically elevated PTH levels (secondary hyperparathyroidism).

Why must hyperphosphatemia be treated? and what is treatment initially focused on?

To prevent bone disease and fractures

restricting dietary phosphate

What medication may be considered in dialysis patients with inadequate response to or intolerance of phosphate binders?

Tenapanor (Xphozah) which is a sodium/H exchanger 3 inhibitor

Why do phosphate levels increase in CKD?

The kidneys cannot adequately eliminate excess phosphate.

Why does vitamin D deficiency occur in CKD? and what does this lead to?

The kidneys cannot activate vitamin D;

causing dietary ca absorption to decrease

How does CKD affect bone health?

Chronic elevation of PTH causes calcium to be pulled from bones, leading to bone demineralization and fractures.

Why can cardiovascular disease occur in CKD-MBD?

Chronically elevated phosphate and calcium levels can cause vascular calcification.

How does CKD contribute to anemia?

The kidneys produce less erythropoietin (EPO), resulting in decreased red blood cell production.

What is the typical dose of aluminum hydroxide for hyperphosphatemia in the setting of CKD?

300-600 mg PO TID with meals (suspension)

When is dialysis required in CKD?

When CKD progresses to kidney failure (Stage 5 disease) in patients who do not receive a kidney transplant

What are the two primary types of dialysis?

Hemodialysis (HD) and peritoneal dialysis (PD)

How does hemodialysis (HD) work?

Blood is pumped through a dialyzer containing a semipermeable filter that removes waste products, electrolytes, and excess fluid

How often is hemodialysis typically performed?

3-4 hours per session, usually 3 times per week

How does peritoneal dialysis (PD) work?

Dialysis solution is infused into the peritoneal cavity, where the peritoneal membrane acts as the semipermeable membrane for waste and electrolyte exchange

Where is peritoneal dialysis typically performed?

At home by the patient

Why may some medications require administration after dialysis?

Dialysis can remove medications from the body

How does molecular size affect drug removal during dialysis?

Smaller molecules are more readily removed by dialysis

How do volume of distribution (Vd) and protein binding affect drug removal during dialysis?

Drugs with a large Vd or high protein binding are less likely to be removed by dialysis

Which dialysis factors increase drug removal?

High-flux/high-efficiency filters and higher dialysis blood flow rates