Should lisinopril be started in a patient with acute kidney injury?

Do Not Start Lisinopril in a Patient with Acute Kidney Injury

Lisinopril should not be initiated in a patient with active acute kidney injury (AKI). The drug can worsen renal function through hemodynamic effects on glomerular filtration and may precipitate further kidney damage during this vulnerable period.

Rationale Based on Guidelines and Drug Labeling

The 2017 ADQI consensus guidelines explicitly recommend avoiding the initiation of chronic medications like ACE inhibitors during AKI episodes when the drug can be delayed until after the acute kidney disease episode has resolved 1. The FDA drug label for lisinopril warns that patients whose renal function may depend on the renin-angiotensin system activity (including those with volume depletion, severe heart failure, or post-MI) are at particular risk of developing acute renal failure on lisinopril 2. The label specifically states to "consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function" 2.

Key Guideline Criteria for Avoiding Nephrotoxin Initiation During AKI:

The ADQI guidelines provide clear criteria when NOT to start a potentially nephrotoxic agent 1:

• Patient has known risk factors for kidney injury (which AKI patients inherently have)
• A suitable alternative is available (other antihypertensives exist)
• The drug is considered non-essential in the acute setting
• Intended duration is chronic and initiation can be delayed until after AKI resolution
• Concern exists for lack of appropriate follow-up of serum creatinine monitoring

All of these criteria apply to starting lisinopril during active AKI.

Mechanism of Harm During AKI

ACE inhibitors like lisinopril reduce glomerular filtration through efferent arteriole dilation, decreasing the filtration fraction 1. While this hemodynamic effect may be tolerable and even beneficial in chronic conditions like heart failure or CKD, these effects are not tolerable and lack proven benefit in patients with AKD 1. The guidelines emphasize that hypotension and decreased filtration fraction can cause or exacerbate AKI 1.

The FDA label confirms that lisinopril can cause "symptomatic hypotension, sometimes complicated by oliguria, progressive azotemia, acute renal failure or death" 2. The drug's mechanism of blocking compensatory angiotensin II formation is particularly problematic when renal perfusion is already compromised 2.

Clinical Algorithm for Decision-Making

If the patient has AKI:

1. Do not initiate lisinopril during the acute phase

2. Delay initiation until:

   • GFR has stabilized 1
   • Volume status is optimized 1
   • The AKI episode has resolved 1
   • Close monitoring of renal function can be ensured

3. Use alternative antihypertensives during the AKI period if blood pressure control is needed

4. Monitor renal function closely if there is a compelling indication requiring ACE inhibitor therapy despite AKI

Dosing Adjustments if Lisinopril Must Be Used:

If there is an absolute indication (such as acute MI with hemodynamic stability), the FDA label provides specific guidance 2:

• For creatinine clearance 10-30 mL/min: reduce initial dose to 2.5-5 mg (half the usual dose)
• For creatinine clearance <10 mL/min or hemodialysis: initial dose 2.5 mg once daily
• Maximum dose 40 mg daily after careful uptitration

Important Caveats and Nuances

The Evidence Is Complex:

While the guidelines recommend caution with ACE inhibitors during AKI, there is contradictory evidence regarding long-term outcomes. A 2018 retrospective study found that ACE inhibitor/ARB use within 6 months after hospital discharge for AKI was associated with lower 2-year mortality (adjusted HR 0.85,95% CI 0.81-0.89), though with higher risk of hospitalization for renal causes 3. However, this study examined post-discharge use after AKI recovery, not initiation during active AKI.

The 2020 KDIGO conference noted that two studies showed increased 30-day mortality when ACE inhibitors/ARBs were not restarted after surgery, possibly from hypertensive rebound and cardiac decompensation 4. This underscores that the question of when to restart differs fundamentally from whether to start during active AKI.

Common Pitfalls to Avoid:

• Do not confuse "restarting" with "initiating": The evidence supporting continuation or early restart of ACE inhibitors in patients previously on these medications differs from starting them de novo during AKI
• Do not assume dose adjustment alone is sufficient: Even with renal dose adjustments, the hemodynamic effects on an already-injured kidney remain problematic
• Do not neglect the indication: If lisinopril is being considered for acute MI with hemodynamic stability, this represents a different risk-benefit calculation than routine hypertension management
• Recognize that lisinopril was identified as a common nephrotoxin in a 2023 study of hospitalized adults, where it contributed to 22% of all inpatient AKI events meeting nephrotoxic AKI criteria 5

Monitoring Requirements if Initiated:

Should lisinopril be started despite AKI (for compelling indications), the FDA label and guidelines mandate 2:

• Very close medical supervision during the first two weeks
• Periodic monitoring of renal function (serum creatinine, eGFR)
• Serum potassium monitoring (risk of hyperkalemia with renal insufficiency)
• Blood pressure monitoring (risk of hypotension)
• Immediate discontinuation if clinically significant renal function decline occurs