An inexpensive, long-established oral medication blocking the body's main pressure-raising hormone. It lowers blood pressure reliably for a full day on one dose, reduces death and hospital admission in heart failure where the pumping chamber is weakened, and reduces migraine days. Falling pressure, rising potassium and reduced kidney filtration are predictable and detectable. No human longevity evidence exists. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Home blood pressure (7-day average) | 110–125 / 70–80 mmHg | The primary target and the main route to benefit |
| Standing blood pressure at 1 and 3 minutes | Systolic drop under 10 mmHg from seated | Detects orthostatic hypotension that predicts falls |
| Serum potassium | 4.0–4.8 mmol/L | The main dose-limiting safety marker for this drug |
| Serum creatinine | Within 30% of the individual's own pre-treatment value | Distinguishes the intended pressure change from kidney injury |
| Estimated glomerular filtration rate | Above 90 mL/min/1.73 m² | Tracks filtration capacity over years |
| Serum sodium | 137–142 mmol/L | Flags volume depletion and over-diuresis |
| Urine albumin-to-creatinine ratio | Under 10 mg/g | Earliest marker of kidney and vascular protection |
| Haemoglobin | 13.5–16.5 g/dL (men), 12.0–15.5 g/dL (women) | Blocking this pathway modestly reduces red-cell production |
Cadence: Baseline before the first dose; chemistry one to two weeks after starting and after each dose increase, then at three months, then every six to twelve months once the dose is stable. Unscheduled repeat after vomiting, diarrhoea, heavy sweating, or the addition of a diuretic or anti-inflammatory. Home blood pressure morning and evening for a week before each review.