Antihypertensive Mechanisms of Minocycline in Resistant Hypertension

This study is testing whether the antibiotic minocycline can lower blood pressure in people with treatment-resistant hypertension — meaning their blood pressure stays high despite taking three or more blood pressure medications. Researchers think minocycline may work by reducing inflammation in the brain and kidneys that contributes to persistent high blood pressure. **You may be eligible if...** - You are 18 or older - Your blood pressure remains uncontrolled (high on 24-hour monitoring) despite being on 3 or more blood pressure medications, including a diuretic (water pill) - You have been on a stable medication regimen for at least 2 weeks - You are willing to have study procedures performed **You may NOT be eligible if...** - You have a known allergy or intolerance to minocycline or other tetracycline antibiotics - You have taken or plan to take oral antibiotics recently (within 3 months) - Your kidney function is significantly impaired (eGFR below 45) - Your high blood pressure is caused by an identifiable underlying condition (secondary hypertension) - You have had a hospitalization for hypertensive crisis Talk to your doctor to see if this trial is right for you.