Efficacy of Plectranthus amboinicus (Lour.) Spreng (French oregano) tablets in patients with common cold: A randomized, double-blind, placebo-controlled study

Abstract

Medicinal plants with healing properties could be used to improve medical attendance. Common cold is a very high frequent disease but their treatment is not always available and adequate. Particularly, French oregano had demonstrated expectorant and antitussive properties at non-clinical level. A randomized, double-blind, placebo-controlled clinical trial was carried out to evaluate if French oregano tablets could quickly suppress common cold symptoms in patients with upper respiratory tract infections, being superior to symptomatic treatment. Patients received placebo or oregano (300 or 600 mg), daily, during 15 days, combined to abundant liquid and antipyretics on the presence of fever or malaise. Each group was formed by 30 patients. The frequency and intensity of cough and the amount of expectoration were assessed weekly. After first week of treatment, cough frequency was significantly lower in those patients treated with 600 mg comparing other groups (p = 0.003). Cough disappeared in 20 patients from the highest dose group. At that time, this group had best results concerning reduction in cough intensity (p = 0.046) and increase in the amount of expectoration (p = 0.041). None patient treated with 600 mg had severe cough after seventh day when a profuse expectoration arose. Therefore, the highest percentage of patients with successful overall response was recorded in this group. Adverse events were mild and mostly attributed to typical disease reactions. French oregano tablets produced a rapid, dependent-dose outcome in patients with common cold, superior to conventional treatment, being also well-tolerated. Cuban Public Registry of Clinical Trials RPCEC00000124.