AKI Therapeutics and Drug-Induced Renal Disorders (Therapeutics, Q1 E1)

What are the criteria for AKIN?

-decrease in renal function over hours to weeks

-increase in SCr

-changes in urine output

How is loss defined per the RIFLE criteria?

complete loss of kidney function for more than 4 weeks

How is End stage kidney disease defined per the RIFLE criteria?

end stage kidney disease for more than 3 months

What are some of the big risk factors for acute kidney injury?

-pre-existing kidney disease

-use of nephrotoxic drugs

-advanced age

-dehydration

What are some of the signs/symptoms for AKI?

-most patients are asymptomatic

-but some symptoms can include malaise, edema, hypertension, abdominal pain or encephalopathy

-patients may be anuric, oligouric or nonoligouric

What are the general points for management of AKI?

-stop the potentially nephrotoxic drugs (like NSAIDs, diuretics, or ACEi/ARBs)

-correct volume deficit (with IV fluids, volume expanders, transfusion)

-optimize cardiac function if needed

What are some ways to monitor a prerenal AKI?

-BUN, creatinine

-urine output

-fluid status (weigt)

-resolution of symptoms

How is acute tubular necrosis managed?

(ATN-type of intrinsic AKI in the tubules)

-remove offending agent if possible

-supportive therapy

-renal replacement therapy if needed (dialysis)

What are some of the causes of Acute Interstitial Nephritis?

(AIN, a type of intrinsic AKI)

-drug induced (could be from NSAIDs, PPIs, or penicillins

-infection related or systems diseases like lupus

What is the management for Acute Interstitial Nephritis?

(AIN, a type of intrinsic AKI)

-discontinue the offending agent if possible

-treat underlying infection/systemic illness

-glucocorticoids like methylprednisone or prednisone

What is the management for Acute Glomerulonephritis?

(GN, a type of instrinsic AKI)

-goal is to stop inflammation and lessen scaring

-specific treatment depends on causative factors and may include glucocorticoids, antibiotics, and diuretics

How do diuretics help in the management of AKI?

-sometimes given to oliguric patients

-do not prevent death or need for renal therapy

-may be useful in managing fluid overload in selected patients

How does dopamine help in the management of AKI?

-increases renal blood flow and natriuresis

-increases urine output but does not decrease mortality or need for renal replacement

(this used to be a routine treatment, but not anymore)

What is the management of the post renal AKI?

-relief of obstruction (put in catheter, stent or nephrostomy

(diuresis after resolution can be extreme, fluid and electrolyte management is critical )

What are some ways to prevent AKI?

-avoid nephrotoxic drugs

-maintain adequate hydration

-avoid hyperglycemia

JE is a 65 year old male with no history of renal disease. He has gastroenteritis that has caused him to have difficulty keeping food and water down. He also had headaches and has been taking ibuprofen 800 mg PO q8h. His SCr today is 2.1 mg/dL (was at 1.0 6 months ago) and his BUN is 55 mg/dL (was 16).

Does he have an AKI, if so what kind?

How should he be managed?

-yes, pre renal

-stop ibuprofen, hydrate

What are some of the risk factors for drug induced AKI?

-use of nephrotoxic drugs or substances

-pre existing kidney disease

-advanced age

-dehydration

-preexisting cardiovascular or respiratory disease

-cardiovascular or major noncardiac surgery

What is a pre-renal AKI?

-very common in inpatient and outpatient settings

-results from decreased renal perfusion

-generally reversible unless hypoperfusion is prolonged

Which medications cause constriction of afferent arterioles?

NSAIDs which inhibit prostaglandin synthesis

What medications cause the dilation of efferent arterioles?

ACE inhibitors and angiotensin receptor blockers

How do you know when to discontinue ACE inhibitors/ARBs because of AKI

-if there is a 30% increase in SCr, hold or discontinue

-increase in SCr may predict long term benefit

-watch K

-re-introduce at a lower dose if strong medication or consider shorter acting alternatives

What is a contrast induced AKI

-acute decline in renal function after administration of IV radiocontrast media in the absence of other precipitants of renal dysfunction

-occurs when there is greater than 25% increase in SCr from baseline

(SCr will typically peak in 3-5 days and returns to baseline within 7-10 days)

What are some of the non-modifiable risk factors of contrast induced AKI

older age, diabetes mellitus, pre-existing renal disease, acute MI, post renal transplant

What are some of the modifiable risk factors for contrast induced risk factors?

volume/type of contrast given, multiple exposure to contrast media within 24-48 hours, dehydration, diuretics or SGLT2 inhibitors, ACE inhibitors, NSAIDs

What are some of the ways that can be used to prevent contrast induced AKI?

-discontinue potentially nephrotoxic drugs

-sodium/volume loading before hand

-acetylcysteine

What is acute interstitial nephritis?

AKI due to infiltration of inflammatory cells in the interstitium and tubules

What is the management for AIN?

(acute interstitial nephritis)

-discontinue the offending agent if possible

-glucocorticoids (methylprednisone or prednisone)

What is the management for drug induced glomerlonephritis?

-discontinue suspected drugs

-specific treatment depends, but may include either immunosuppressants or diuretics

Which kind of drugs can cause similar effects to a post renal AKI?

anticholinergics

What is the management of post renal AKI?

relief of obstruction (be careful because diuresis after resolution can be extreme)

What are some examples of drugs that can crystallize in the urine

acyclovir, allopurinol, quinolones, sulfonamides, methotrexate, and triamterene

What is the treatment for drug crystalluria

hydration, supportive care, consider alternate drugs

What is Drug-induced CKD

-it is the result of an acute injury with less than full recovery

-still has the 90 day time component

-some examples are aminoglycoside induced ATN or amphotericin B induced ATN

What is the treatment of drug induced CKD

-remove the offending agent if possible

-treat CKD related issued when needed