Aviptadil is a synthetic copy of a natural signalling molecule that relaxes blood vessels and airways and quietens immune cells. Injected locally with a second drug, it restores erections in men who have failed other treatments — its strongest evidence, licensed in a few countries. For failing lungs, infusion or inhalation improves oxygen transfer briefly, but not survival. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Systolic / diastolic blood pressure | 110–125 / 70–80 mmHg | Detects the commonest systemic effect |
| Resting heart rate | 55–70 bpm | Tachycardia accompanies flushing |
| Oxygen saturation on room air | 95–99% | Tracks the main claimed respiratory effect |
| PaO₂/FiO₂ ratio | Above 300 | The endpoint on which trial benefit was claimed |
| High-sensitivity C-reactive protein (hs-CRP) | Below 0.5 mg/L | Anchors the anti-inflammatory claim |
| Interleukin-6 | No established treatment target; track the change from the individual's own day-0 value | The biomarker on which the sponsor trial rested |
| Platelet count | 175–250 × 10⁹/L | Governs injection-site bleeding risk |
| Prothrombin time / INR | 0.9–1.1 | Anticoagulation bars the injectable route |
| Serum sodium | 137–142 mmol/L | Detects losses from secretory diarrhoea |
| Serum potassium | 4.0–4.5 mmol/L | Diarrhoea depletes potassium fastest |
| Total testosterone | 600–900 ng/dL | Identifies a correctable cause of erectile dysfunction |
| Haemoglobin electrophoresis (sickle-cell screen) | Negative for sickle haemoglobin | Sickle disease or trait bars injectable use |
Cadence: Blood pressure and heart rate continuously throughout each infusion; oxygen saturation and oxygenation ratio daily on days 1 through 3; electrolytes on day 3 if diarrhoea occurs; inflammatory markers at days 3 and 7; clinical review at 4 weeks. Injectable users are reviewed at 6 weeks, then roughly every 3 months.