What is the recommended dose of enalapril (Angiotensin-Converting Enzyme (ACE) inhibitor) for chemoprotection in normotensive patients?

Enalapril Dosing for Chemoprotection in Normotensive Patients

For normotensive patients requiring chemoprotection, enalapril should be initiated at 2.5 mg twice daily and titrated up to 10 mg twice daily as tolerated.

Dosing Recommendations

The optimal dosing strategy for enalapril in normotensive patients for chemoprotection is based on clinical evidence showing efficacy while minimizing adverse effects:

• Initial dose: 2.5 mg twice daily
• Target dose: 10 mg twice daily
• Titration: Gradual increase over several weeks as tolerated

This dosing recommendation is supported by the Symptomatic Cardiac Obstruction-Pilot Study of Enalapril in Aortic Stenosis (SCOPE-AS), which demonstrated that gradual titration of enalapril from 2.5 mg twice daily to 10 mg twice daily was well tolerated even in patients with symptomatic severe aortic stenosis 1.

Monitoring Parameters

When initiating enalapril in normotensive patients:

• Check baseline renal function and serum potassium
• Monitor blood pressure within 1-2 weeks of initiation and dose changes
• Assess renal function and potassium within 1-2 weeks of starting therapy
• Continue periodic monitoring throughout treatment

Clinical Considerations

Efficacy

Enalapril has demonstrated effectiveness in providing cardioprotection at doses ranging from 2.5-20 mg daily, with most clinical benefits achieved in the 10-20 mg daily range 1. The mean dose achieved in clinical trials was 16.6 mg daily 1.

Safety in Normotensive Patients

• Lower doses are particularly important in normotensive patients to avoid hypotension
• Starting with 2.5 mg twice daily minimizes the risk of first-dose hypotension
• Gradual titration improves tolerability

Potential Adverse Effects

• Hypotension (particularly first-dose)
• Cough (occurs in up to 20% of patients)
• Hyperkalemia
• Angioedema (rare but serious)
• Renal function decline (especially with pre-existing renal impairment)

Special Populations

• Renal impairment: Lower doses (1.25-2.5 mg daily) may be appropriate for patients with reduced renal function 2
• Elderly: Consider starting at the lower end of the dosing range (2.5 mg daily)
• Concomitant diuretic therapy: Consider temporarily discontinuing diuretics 2-3 days before initiating enalapril to reduce risk of hypotension

Practical Implementation

1. Begin with 2.5 mg twice daily for 1-2 weeks
2. If well tolerated, increase to 5 mg twice daily for 1-2 weeks
3. Further increase to 7.5 mg twice daily if needed and tolerated
4. Aim for target dose of 10 mg twice daily if tolerated
5. If adverse effects occur, reduce to the highest tolerated dose

This approach balances the need for adequate ACE inhibition for cardioprotection while minimizing the risk of adverse effects in normotensive patients.