When to discontinue antihypertensive (blood pressure) medications, such as Angiotensin-Converting Enzyme inhibitors (ACE inhibitors), Angiotensin Receptor Blockers (ARBs), diuretics, beta-blockers, and calcium channel blockers, in patients with acute illness and significant volume depletion, aside from preventing hypotension (low blood pressure) and acute kidney injury (Impaired renal function)?

When to Discontinue Antihypertensive Medications in Acute Illness with Volume Depletion

Antihypertensive medications, particularly RAAS blockers (ACE inhibitors, ARBs, aldosterone antagonists) and diuretics, should be temporarily suspended during acute illness with significant volume depletion, planned procedures requiring bowel preparation or IV contrast, or prior to major surgery to prevent acute kidney injury and hemodynamic instability. 1

Primary Indications for Temporary Discontinuation

RAAS Blockers (ACE Inhibitors, ARBs, Aldosterone Antagonists)

Temporarily suspend RAAS blockers in the following scenarios: 1

• Intercurrent illness with volume depletion (gastroenteritis, fever, reduced oral intake) 1
• Planned IV radiocontrast administration 1
• Bowel preparation prior to colonoscopy 1
• Prior to major surgery 1
• Significant worsening of renal function (though this requires nuanced interpretation—see below) 1

The rationale is that RAAS blockers reduce efferent arteriolar tone, making glomerular filtration critically dependent on adequate renal perfusion pressure. 2 In volume-depleted states, this can precipitate acute renal failure that is reversible after drug withdrawal. 2

Diuretics

Hold diuretics during acute volume depletion to prevent further intravascular volume loss and hypotension. 1 This is particularly important when combined with RAAS blockers, as the combination potentiates both therapeutic and adverse hemodynamic effects. 2

Beta-Blockers

Consider withholding or reducing beta-blockers in patients with: 1

• Marked volume overload requiring aggressive diuresis 1
• Marginal or low cardiac output states 1
• Recent initiation or dose escalation of beta-blocker therapy 1

Beta-blockers have direct negative inotropic effects and can cause significant hypotension, especially in patients with compromised cardiac function. 3

Critical Exceptions: When NOT to Discontinue

RAAS Blockers Should Be Continued Despite Creatinine Elevation

Do not discontinue RAAS blockers for minor increases in serum creatinine (<30% from baseline), as this represents expected hemodynamic changes rather than acute kidney injury. 1

• Small creatinine elevations up to 30% with RAAS blockers are acceptable and should not be confused with AKI 1
• The ACCORD BP trial demonstrated that patients with up to 30% creatinine increase had no increased mortality or progressive kidney disease 1
• RAAS blockers remain nephroprotective even in advanced CKD (eGFR <30 mL/min/1.73 m²) when dosed appropriately 1
• Do not routinely discontinue RAAS blockers in patients with GFR <30 mL/min/1.73 m² as they remain nephroprotective 1

Heart Failure Patients

In patients with heart failure admitted with symptomatic exacerbation, continue guideline-directed medical therapy (including RAAS blockers and beta-blockers) in the absence of hemodynamic instability or contraindications. 1

• Continuation of ACE inhibitors/ARBs and beta-blockers in hospitalized heart failure patients is well tolerated and results in better outcomes 1
• Only consider withholding beta-blockers in patients with marked volume overload or marginal cardiac output 1

Practical Algorithm for Decision-Making

Step 1: Assess Volume Status and Hemodynamic Stability

Evaluate for:

• Signs of volume depletion (orthostatic hypotension, reduced skin turgor, dry mucous membranes) 1
• Symptomatic hypotension (dizziness, lightheadedness, altered mental status) 4
• Acute illness causing reduced oral intake or increased fluid losses 1

Step 2: Identify High-Risk Scenarios

Temporarily discontinue RAAS blockers and diuretics if:

• Active gastroenteritis, vomiting, or diarrhea 1
• Scheduled for procedures requiring bowel preparation 1
• Planned IV contrast administration within 48 hours 1
• Major surgery scheduled 1
• Symptomatic hypotension with evidence of end-organ hypoperfusion 1

Step 3: Monitor Renal Function Appropriately

For creatinine increases with RAAS blockers:

• <30% increase: Continue therapy, monitor potassium 1
• >30% increase within 4 weeks: Consider dose reduction or temporary discontinuation 5
• Associated with hyperkalemia (K+ >5.5 mEq/L): Adjust or discontinue 1

Step 4: Restart Medications Systematically

After resolution of acute illness:

• Restart RAAS blockers once volume status normalized and renal function stable 1
• Reassess GFR and potassium within 1 week of restarting 1
• Resume beta-blockers after optimization of volume status and discontinuation of IV diuretics/inotropes 1

Common Pitfalls and How to Avoid Them

Pitfall 1: Discontinuing RAAS Blockers for Minor Creatinine Elevations

Avoid: Stopping ACE inhibitors/ARBs for creatinine increases <30% 1

Why: This represents expected hemodynamic effects, not AKI. All clinical trials demonstrating efficacy used maximally tolerated doses, not low doses that avoid any creatinine rise. 1

Pitfall 2: Abrupt Discontinuation of Beta-Blockers

Avoid: Suddenly stopping beta-blockers without tapering 6

Why: Abrupt cessation can cause rebound hypertension, tachycardia, or acute coronary syndromes, particularly with high doses or in patients with ischemic heart disease. 6 Gradual tapering over 7-10 days prevents these complications. 6

Pitfall 3: Permanent Discontinuation in Chronic Kidney Disease

Avoid: Permanently stopping RAAS blockers in patients with eGFR <30 mL/min/1.73 m² 1

Why: These medications remain nephroprotective even in advanced CKD and improve mortality outcomes. 1 Temporary suspension during acute illness is appropriate, but they should be restarted once stable. 1

Pitfall 4: Failing to Restart Medications After Acute Illness

Avoid: Leaving patients off their chronic antihypertensive therapy indefinitely after temporary discontinuation 7

Why: While temporary discontinuation for diagnostic evaluation or acute illness is safe in controlled settings, long-term withdrawal increases cardiovascular risk. 8 Systematic restart protocols should be in place. 1

Special Populations

Elderly Patients

• More susceptible to hypotension due to decreased baroreceptor response 4
• Measure blood pressure in both sitting and standing positions to detect orthostatic hypotension 5
• Initial doses should be more gradual, but no age-based contraindication exists 5

Patients on Multiple Antihypertensives

• Higher risk for hypotension when medications are combined 4
• Consider reducing doses of other agents (e.g., diuretics) before discontinuing RAAS blockers entirely 4
• Administer medications at different times of day to minimize additive hypotensive effects 4

Monitoring After Medication Changes

Within 2-4 weeks of discontinuation or restart: 5

• Measure serum creatinine and eGFR 5
• Check serum potassium 5
• Assess blood pressure (sitting and standing) 5

During acute illness: 1

• Daily assessment of fluid intake/output, vital signs, and body weight 1
• Daily serum electrolytes, urea nitrogen, and creatinine 1