Summary
In 260 adults with cold symptoms, 0.5% povidone-iodine spray four times daily for five days gave a 12.6% benefit on the global severity score over saline (p=0.054, not significant). The benefit was larger when treated within 24 hours of onset (39.7%, p=0.024) and in virus-confirmed cases (23.0%, p=0.048), which are subgroup results.
Key points
- On the main outcome, nasal symptoms, the benefit over saline spray was 8.4% and not statistically significant (p = 0.217).
- On overall cold severity, the benefit was 12.6% (p = 0.054), just short of significance.
- In subgroups chosen after the trial, the benefit was larger: 39.7% when started within 24 hours of symptoms (p = 0.024) and 23.0% in confirmed viral infections (p = 0.048).
- Mild, short-lived nose and throat discomfort was a common side effect.
- Design: multicenter, randomized, double-blind, saline-controlled Phase III trial in 260 adults.
- Funding: Firebrick Pharma, the product maker; the first author works for the contract research organization and a co-author consults for the sponsor.