What precautions should be taken when starting a patient with a history of cardiovascular disease, diabetes, or kidney disease on lisinopril (angiotensin-converting enzyme inhibitor)?

Precautions When Starting Lisinopril

Before initiating lisinopril, assess baseline blood pressure, renal function (serum creatinine), and serum potassium, then reassess these parameters within 2-4 weeks after starting therapy or any dose increase. 1

Pre-Initiation Assessment

Absolute Contraindications

• History of angioedema from any cause, particularly prior ACE inhibitor-related angioedema—this is life-threatening and justifies lifetime avoidance of all ACE inhibitors 1, 2
• Pregnancy (second and third trimesters)—discontinue immediately if pregnancy is detected due to risk of fetal renal dysgenesis, oligohydramnios, and death 3, 2
• Bilateral renal artery stenosis 1

High-Risk Populations Requiring Cautious Initiation

• Systolic blood pressure <80-90 mmHg—start under close medical supervision with lower initial doses 1, 2
• Serum creatinine >3 mg/dL—requires dose adjustment and close monitoring 1, 2
• Serum potassium >5.5 mmol/L—address hyperkalemia before initiation 1
• Volume depletion or high-dose diuretic therapy—correct volume status first to prevent excessive hypotension 1, 2
• Acute myocardial infarction with hemodynamic instability—avoid until stabilized 2

Starting Dose Strategy

Standard Initiation

• Begin with low doses: 5-10 mg once daily for hypertension, 5 mg for heart failure, 2.5-5 mg for post-MI patients 1, 3, 4
• Titrate gradually by doubling doses if lower doses are well tolerated 1

Dose Adjustment for Renal Impairment

• Creatinine clearance 10-30 mL/min: reduce initial dose to 5 mg daily 3, 2
• Hemodialysis patients: dose adjustment required 2
• Creatinine clearance >30 mL/min: no adjustment needed 2

Critical Monitoring Protocol

Timing: 2-4 Weeks After Initiation or Dose Change

Monitor three key parameters 1:

1. Blood pressure (including orthostatic measurements in elderly or symptomatic patients) 1
2. Serum creatinine 1
3. Serum potassium 1

Interpretation of Monitoring Results

Serum Creatinine Rise 1:

• <30% increase: Continue therapy and monitor
• >30% increase within 4 weeks:
  • Review for acute kidney injury causes
  • Correct volume depletion
  • Reassess concomitant medications (NSAIDs, diuretics)
  • Consider renal artery stenosis
  • May need to reduce dose or discontinue

Hyperkalemia Management 1:

• Do not immediately discontinue—attempt management first:
  • Review concurrent potassium-sparing drugs
  • Moderate dietary potassium intake
  • Consider diuretics, sodium bicarbonate, or GI cation exchangers
• Reduce dose or stop lisinopril only as last resort

Special Population Considerations

Patients with Diabetes and CKD

• Automatically high-risk category—initiate therapy promptly if hypertensive with albuminuria 1
• Titrate to highest tolerated dose for maximal renoprotection 1
• Monitor more frequently due to increased risk of hyperkalemia 1

Black Patients

• Higher risk of angioedema compared to non-Black patients 2
• Less blood pressure response to ACE inhibitor monotherapy—often requires combination with calcium channel blocker or thiazide diuretic 2

Elderly Patients

• Screen for orthostatic hypotension at each visit 1
• May require lower initial doses (2.5-5 mg) 4
• No routine dose adjustment needed based on age alone 2

Women of Childbearing Age

• Advise contraception before starting therapy 1
• Discontinue immediately if pregnancy occurs 1, 2

Concomitant Medication Precautions

Avoid or Use with Extreme Caution

• Potassium supplements or potassium-sparing diuretics—increases hyperkalemia risk 2
• NSAIDs—may worsen renal function and blunt antihypertensive effect 1
• Triple therapy (ACE inhibitor + ARB + aldosterone antagonist)—potentially harmful 1

Requires Close Monitoring

• Diuretics—may cause excessive hypotension, especially with first dose 2, 4
• Lithium—ACE inhibitors can increase lithium levels 5

Common Pitfalls to Avoid

• Do not delay ACE inhibitor therapy in heart failure patients waiting to optimize other medications—start early for mortality benefit 1
• Do not discontinue for mild cough without considering alternatives—occurs in up to 20% but is usually tolerable 1
• Do not avoid in renal impairment—adjust dose appropriately rather than withholding, as these patients often benefit most 1
• Do not start during acute volume depletion—correct first to prevent acute kidney injury 1, 2
• Do not combine with ARB routinely—increases risk without clear benefit in most patients 1