A new patient who was previously on enalapril 2.5 mg and stopped because of insurance now has blood pressure 148/86 mm Hg; should I restart enalapril or prescribe a different antihypertensive?

Restart Enalapril 2.5 mg Daily

You should restart enalapril 2.5 mg once daily in this patient with blood pressure 148/86 mm Hg. 1 This represents stage 1 hypertension requiring pharmacologic treatment, and the patient has already demonstrated tolerability to this specific ACE inhibitor at this dose. 2

Rationale for Restarting Enalapril

Blood Pressure Threshold Met

• The current BP of 148/86 mm Hg exceeds the treatment threshold of 140/90 mm Hg for initiating or resuming antihypertensive therapy. 2
• Stage 1 hypertension (130-139/80-89 mm Hg) warrants treatment, and this patient's BP is even higher at 148/86 mm Hg. 2

Prior Tolerability Established

• The patient previously tolerated enalapril 2.5 mg without documented adverse effects (the discontinuation was insurance-related, not due to side effects). 1
• Enalapril 2.5 mg is the appropriate starting dose for patients with uncomplicated hypertension. 1

ACE Inhibitors as First-Line Therapy

• ACE inhibitors are recommended as first-line monotherapy for hypertension, particularly in patients who have previously responded well. 2
• Enalapril has proven efficacy in lowering blood pressure across all grades of essential hypertension. 3, 4

Pre-Restart Monitoring Requirements

Essential Laboratory Tests

• Measure serum creatinine and estimate GFR before restarting to identify patients at risk for acute renal failure and determine appropriate dosing. 5
• Check serum potassium to establish baseline, as ACE inhibitors can cause hyperkalemia. 2, 5
• Perform urinalysis for proteinuria to gauge baseline kidney disease severity. 5

Clinical Assessment

• Assess volume status by checking for orthostatic hypotension, reduced skin turgor, or dry mucous membranes, as volume depletion increases risk of ACE inhibitor-induced acute renal failure. 5
• Screen for bilateral renal artery stenosis in patients with multiple atherosclerotic risk factors, as ACE inhibitors can cause reversible acute renal failure in this population. 5
• Review concomitant medications for nephrotoxic agents (NSAIDs, aminoglycosides) that increase acute renal failure risk when combined with ACE inhibitors. 5

Dosing Strategy

Initial Dose

• Start with enalapril 2.5 mg once daily, the same dose the patient previously tolerated. 1
• This is the FDA-recommended starting dose for patients not currently on diuretics. 1

Titration Plan

• Recheck BP in 2-4 weeks to assess response. 1
• If BP remains >140/90 mm Hg, increase to 5 mg once daily, then titrate to 10-20 mg daily as needed. 2, 1
• The usual maintenance dosage range is 10-40 mg per day, administered once daily or in two divided doses. 1
• Target doses from clinical trials averaged 16.6 mg/day for enalapril. 2

Post-Restart Monitoring

Early Laboratory Follow-Up

• Recheck serum creatinine and potassium within 1-2 weeks of restarting enalapril, as acute changes typically occur promptly after initiation. 2, 5
• A 10-20% rise in serum creatinine is expected and reflects hemodynamic changes rather than structural kidney injury. 5
• If creatinine rises >20% or potassium exceeds 5.5 mEq/L, investigate precipitating factors (hypotension, volume depletion, nephrotoxins, renal artery stenosis). 5

Why Not Switch to a Different Agent?

No Indication to Change

• There is no evidence of prior enalapril failure or intolerance. 1
• Switching to a different antihypertensive class would require establishing new tolerability without clear benefit. 2
• All ACE inhibitors have similar efficacy in hypertension, so switching within the class offers no advantage. 2

Enalapril's Proven Track Record

• Enalapril demonstrates equivalent efficacy to other ACE inhibitors, beta-blockers, calcium channel blockers, and diuretics for blood pressure control. 3, 4
• The patient's previous response to enalapril makes it the logical choice for resumption. 4

Common Pitfalls to Avoid

Do Not Withhold Due to Modest BP Elevation

• BP of 148/86 mm Hg is not a hypertensive emergency and does not require intravenous therapy or emergency department referral. 6
• Oral antihypertensive agents are preferred for this level of BP elevation. 6

Do Not Start with Excessive Caution

• Systolic BP of 148 mm Hg is well above the threshold where ACE inhibitors cause problematic hypotension (systolic <80 mm Hg). 2
• The patient is not volume depleted or in acute heart failure, so standard dosing applies. 1

Do Not Add Diuretic Initially

• Monotherapy with enalapril should be attempted first, as many patients achieve adequate BP control without combination therapy. 1
• If BP remains uncontrolled after titrating enalapril to 10-20 mg daily, then add hydrochlorothiazide 12.5-25 mg daily. 2, 1