Efficacy and safety of an antiviral Iota-Carrageenan nasal spray: a randomized, double-blind, placebo-controlled exploratory study in volunteers with early symptoms of the common cold

Respir Res. 2010 Aug 10;11(1):108. doi: 10.1186/1465-9921-11-108.


Background: The common cold, the most prevalent contagious viral disease in humans still lacks a safe and effective antiviral treatment. Iota-Carrageenan is broadly active against respiratory viruses in-vitro and has an excellent safety profile. This study investigated the efficacy and safety of an Iota-Carrageenan nasal spray in patients with common cold symptoms.

Methods: In a randomized, double-blind, placebo-controlled exploratory trial, 35 human subjects suffering from early symptoms of common cold received Iota-Carrageenan (0.12%) in a saline solution three times daily for 4 days, compared to placebo.

Results: Administration of Iota-Carrageenan nasal spray reduced the symptoms of common cold (p = 0.046) and the viral load in nasal lavages (p = 0.009) in patients with early symptoms of common cold. Pro-inflammatory mediators FGF-2, Fractalkine, GRO, G-CSF, IL-8, IL-1alpha, IP-10, IL-10, and IFN-alpha2 were reduced in the Iota-Carrageenan group.

Conclusions: Iota-Carrageenan nasal spray appears to be a promising treatment for safe and effective treatment of early symptoms of common cold. Larger trials are indicated to confirm the results.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Aerosols
  • Antiviral Agents / administration & dosage*
  • Antiviral Agents / adverse effects
  • Carrageenan / administration & dosage*
  • Carrageenan / adverse effects
  • Common Cold / drug therapy*
  • Common Cold / immunology
  • Common Cold / virology
  • Double-Blind Method
  • Female
  • Humans
  • Inflammation Mediators / metabolism
  • Male
  • Nasal Lavage Fluid / immunology
  • Nasal Lavage Fluid / virology
  • Time Factors
  • Treatment Outcome
  • Viral Load
  • Young Adult


  • Aerosols
  • Antiviral Agents
  • Inflammation Mediators
  • Carrageenan