Should perindopril be discontinued in a patient with diabetic ketoacidosis and hyperkalaemia (serum potassium 5.3 mmol/L)?

Temporarily hold perindopril during acute DKA management, but plan for prompt reinitiation once the acute crisis resolves

In a patient with diabetic ketoacidosis and hyperkalaemia (K+ 5.3 mmol/L), perindopril should be temporarily discontinued during the acute DKA episode, but this should NOT be a long-term strategy—the ACE inhibitor must be restarted as soon as the acute metabolic derangement is corrected.

Rationale for Temporary Discontinuation

The potassium level of 5.3 mmol/L represents mild hyperkalaemia (>5.0 to <5.5 mmol/L) 1. While this level alone would not typically mandate ACE inhibitor discontinuation in stable patients, the context of DKA changes the clinical picture significantly:

• DKA causes a paradoxical state: Despite total body potassium depletion, serum potassium is often normal or elevated due to insulin deficiency, acidosis, and hyperosmolality 2
• Perindopril contributes to hyperkalaemia through RAAS inhibition, particularly in patients with diabetes and renal impairment 3
• The combination of DKA + ACE inhibitor creates compounding risk for severe hyperkalaemia during the acute phase 2

The FDA label explicitly states that in some cases, "discontinuation of either or both drugs may be necessary" when managing hyperkalaemia, particularly with concurrent conditions affecting potassium homeostasis 3.

Critical Management Principles

During Acute DKA Phase:

1. Hold perindopril temporarily while managing the acute metabolic crisis
2. Monitor potassium closely during DKA treatment—potassium will initially drop with insulin therapy and fluid resuscitation
3. Maintain potassium >10 mmol/L during replacement (levels below this are associated with higher mortality) 4
4. Address the precipitating cause of DKA

After DKA Resolution:

The most important principle: Down-titration or discontinuation of ACE inhibitors should NOT be the default long-term strategy for hyperkalaemia 5. The evidence is unequivocal:

• Discontinuing RAASi therapy increases mortality and worsens cardiorenal outcomes 5, 1
• Continuation of ACE inhibitor therapy consistently decreases cardiovascular and kidney outcomes and death, regardless of short-term potassium changes 6
• In the ADVANCE trial, patients who developed hyperkalaemia (≥5.0 mmol/L) during ACE inhibitor initiation still benefited from continued therapy with reduced macrovascular and microvascular events 6

Reinitiation Strategy

Restart perindopril promptly once:

• DKA has resolved (anion gap closed, pH normalized)
• Potassium is stable in the normal range
• Patient is tolerating oral intake
• Renal function is reassessed

Alternative management approaches to enable RAASi continuation 5, 1:

• Regular potassium monitoring (2-4 times yearly for patients with diabetes)
• Dietary potassium modification
• Consider potassium-wasting diuretics if volume status permits
• Newer potassium binders (sodium zirconium cyclosilicate or patiromer) can maintain normokalaemia long-term and enable continued RAASi therapy 5
• Avoid potassium supplements and salt substitutes 3

Common Pitfalls to Avoid

1. Permanent discontinuation after a single hyperkalaemia episode: This is the most critical error—it increases mortality 5, 1
2. Assuming elevated potassium in DKA reflects true body stores: Total body potassium is actually depleted despite elevated serum levels 2
3. Failing to reassess and restart the ACE inhibitor: Many patients never get back on disease-modifying therapy after acute illness 5
4. Not considering potassium binders: These enable continuation of life-saving RAASi therapy 5

Special Considerations in This Patient

The combination of diabetes + hyperkalaemia + ACE inhibitor represents the exact population where:

• Risk of recurrent hyperkalaemia is highest 3
• Benefit from continued RAASi therapy is greatest (cardiovascular and renal protection) 6
• Proactive management strategies are most important 5, 1

The goal is not to avoid hyperkalaemia by stopping perindopril—the goal is to manage potassium levels while maintaining the mortality benefit of ACE inhibition 5, 1.