Hypertension Resistant to First-Line Therapy

Clinical History

‍52-year-old male, BP consistently 148–52/92–96 on lisinopril 40mg and amlodipine 10mg for four months. Reports adherence, confirmed by pharmacy refill records. BMI 31. No end-organ damage. BMP and UA normal. No secondary HTN workup done.

Clinical Question

‍He’s on two agents at good doses and still not controlled. Should I add a third? Should I be looking for a secondary cause?

Specialist Guidance

‍First, confirm adherence and make sure proper measurement technique is being used (appropriately sized cuff, seated, rested, feet on the floor). Get home BP readings to confirm the office numbers. Review his medication list for anything that could be contributing to elevated BP, such as NSAIDs, stimulants, or decongestants. Make sure lifestyle factors are optimized: sodium restriction, weight management given the BMI of 31, limiting alcohol and caffeine, and stress reduction.

For the third agent, add a thiazide diuretic. Either HCTZ 25mg or chlorthalidone 12.5mg is reasonable. Check BMP in 2–4 weeks for potassium and creatinine.

Given his age and the degree of resistance on two agents, it would also be reasonable to send a secondary hypertension workup now. Check an aldosterone-to-renin ratio, cortisol, and TSH if not recently done. If the aldo/renin ratio is elevated, that will need further evaluation, likely with a specialist, to confirm primary aldosteronism. Also consider comorbidities when choosing the third agent. If there’s any concern for heart failure with reduced ejection fraction, spironolactone or a beta blocker would be preferred over a standard thiazide.

No cardiology referral needed at this stage for medication optimization alone.

Outcome

Home BP confirmed persistent hypertension. Medication review clean. Added HCTZ 25mg. Lifestyle counseling provided. Secondary workup sent: aldo/renin ratio, cortisol, TSH all normal. BP improved to 134/86 at 6-week follow-up. Managed entirely in primary care. No referral required.

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