A 52-year-old man from Delhi presents with a 3-year history of hypertension managed with atenolol 50 mg daily. His BP today is 148/94 mmHg. He complains of fatigue, erectile dysfunction, and reduced exercise tolerance. Fasting glucose is 118 mg/dL (previously 105 mg/dL 6 months ago). Lipid panel shows total cholesterol 220 mg/dL and triglycerides 165 mg/dL. He has no history of diabetes or CAD. Which antihypertensive would be most appropriate to replace atenolol?

Explanation

## Clinical Context This patient has multiple metabolic side effects from beta-blocker therapy: fatigue, erectile dysfunction, worsening glucose tolerance, and dyslipidemia. The goal is to switch to an agent that avoids these adverse effects while maintaining BP control. ## Why Enalapril Is Correct **Key Point:** ACE inhibitors are the preferred second-line agent in patients with metabolic complications from beta-blockers, particularly those with impaired fasting glucose or dyslipidemia. **High-Yield:** ACE inhibitors offer: - No adverse metabolic effects (neutral on glucose and lipids) - Improved insulin sensitivity - Renal protective effects (important for long-term hypertension management) - Beneficial effects on erectile function (improved endothelial function) - Reduction in cardiovascular events in hypertensive patients **Clinical Pearl:** The patient's fasting glucose of 118 mg/dL suggests impaired fasting glucose (IFG), a metabolic syndrome component. Beta-blockers worsen glucose homeostasis by impairing insulin secretion and increasing insulin resistance. ACE inhibitors improve insulin sensitivity and are ideal in this setting. ## Mechanism of Benefit ACE inhibitors block angiotensin II formation, reducing vasoconstriction and aldosterone secretion. They improve endothelial function and have favorable effects on the metabolic syndrome cluster. ## Comparison with Alternatives | Agent | Metabolic Effect | Erectile Function | Indication Here | |-------|------------------|-------------------|------------------| | Amlodipine | Neutral | Neutral | Good alternative, but less metabolic benefit | | Enalapril | Improves insulin sensitivity | Improves | **Best choice** | | HCTZ | Worsens glucose & lipids | Neutral/negative | Contraindicated—worsens metabolic profile | | Labetalol | Similar to atenolol | Negative | Not ideal—retains beta-blocker side effects | **Warning:** Thiazide diuretics (like HCTZ) worsen glucose tolerance and lipid profile, making them unsuitable here despite BP-lowering efficacy.