What is the most effective medication for a middle-aged man with uncontrolled hypertension (high blood pressure) and benign prostatic hyperplasia (BPH) symptoms, who is currently taking lisinopril (Angiotensin-Converting Enzyme Inhibitor) and amlodipine (Calcium Channel Blocker)?

Doxazosin is the Most Effective Medication for Treating Both Conditions

Doxazosin is the optimal choice for this patient because it is the only medication among the options that simultaneously treats both uncontrolled hypertension and BPH symptoms with a single agent. 1

Rationale for Doxazosin Selection

Dual Therapeutic Benefit

• Doxazosin is FDA-approved for both hypertension and BPH, making it uniquely suited to address both conditions in this patient who has failed dual antihypertensive therapy and has symptomatic BPH. 1
• Alpha-1 blockers like doxazosin relax prostatic smooth muscle tone, improving urinary flow and reducing BPH symptoms, while simultaneously lowering blood pressure through vascular smooth muscle relaxation. 2, 3
• Clinical trials demonstrate that doxazosin significantly improves AUA symptom scores and urinary flow rates in BPH patients while providing clinically meaningful blood pressure reductions (average 10 mmHg systolic/diastolic). 3, 4

Evidence in Patients with Both Conditions

• In patients with concomitant BPH and inadequately controlled hypertension despite treatment with other antihypertensives, adding doxazosin resulted in improved BP control with significant reductions, achieving goal BP (<140/90 mmHg) in many patients. 3, 5, 4
• The HABIT trial (n=491) specifically evaluated patients with both symptomatic BPH and hypertension, showing that doxazosin significantly improved all BPH symptom scores regardless of initial severity while achieving adequate blood pressure control. 4
• Doxazosin works effectively as add-on therapy to ACE inhibitors and calcium channel blockers (which this patient is already taking), making it an ideal third agent. 4

Why Other Options Are Inferior

Finasteride (Option B)

• Finasteride only treats BPH and has no antihypertensive effect, leaving the patient's uncontrolled hypertension unaddressed. 6
• Finasteride requires 3-6 months to show symptomatic benefit, whereas alpha-blockers provide relief within 3-5 days. 6
• While finasteride is appropriate for patients with enlarged prostates (>30cc), it does not address the immediate need for blood pressure control. 6

Hydralazine (Option C)

• Hydralazine only treats hypertension and has no effect on BPH symptoms. 1
• This would require adding a separate medication for BPH, unnecessarily increasing pill burden and cost.

Hydrochlorothiazide (Option D)

• Thiazide diuretics only treat hypertension and have no effect on BPH. 1
• Adding a diuretic may actually worsen nocturia and urinary frequency, which are already problematic BPH symptoms in this patient.

Metoprolol (Option E)

• Beta-blockers only treat hypertension and have no effect on BPH symptoms. 1
• This would not address the patient's urinary complaints.

Critical Safety Consideration

Heart Failure Warning

• The American Urological Association recommends avoiding doxazosin in patients with heart failure due to increased risk of congestive heart failure exacerbation; however, this patient has no documented heart failure, making doxazosin safe to use. 7
• If this patient had heart failure, tamsulosin would be the preferred alpha-blocker instead. 7

Implementation Strategy

Dosing and Titration

• Start doxazosin at 1 mg once daily at bedtime to minimize first-dose orthostatic hypotension. 2
• Titrate gradually (doubling the dose every 1-2 weeks) up to 4-8 mg daily as needed for BP and symptom control. 2
• The newer doxazosin GITS formulation can be initiated at therapeutic doses, simplifying titration. 5

Monitoring Parameters

• Reassess blood pressure at each titration visit, targeting <140/90 mmHg. 4
• Reassess BPH symptoms using IPSS scores at 4-6 weeks to evaluate response. 7
• Monitor for orthostatic hypotension, particularly in the first few weeks of therapy. 7

Future Considerations

• If the patient has documented prostate enlargement >30cc on imaging, consider adding finasteride 5 mg daily after achieving symptom control with doxazosin to prevent long-term disease progression (67% reduction in acute urinary retention and need for surgery). 6
• Combination therapy with an alpha-blocker plus 5-alpha-reductase inhibitor provides superior long-term outcomes compared to monotherapy alone. 6