Anti-aggravating effects of kakkonto, a Chinese herb, for common colds: a randomized controlled trial

INTERVENTION: Kakkonto three times a day before meal or 2 hours after meal for 4 days in principle. The western cold medicine named "Pabron Gold A" produced by Taisho Pharmaceutical three times a day after meal for 4 days in principle. CONDITION: common cold PRIMARY OUTCOME: The primary outcome is whether one of the 3 symptoms, the nasal, pharyngeal, and tracheal symptoms, will be moderate or severe in the self‐reporting questionnaire for 2 days or more during the first 5 days from the beginning of the treatment. ("Moderate" is defined as when a patient always feels discomfort and "severe" is defined as when a patient experiences difficulties in daily life.) If some individual cold symptoms were evaluated as "moderate" before the treatment, we will check up on whether they will be severe for more than two days during the first five days from the beginning of the treatment. SECONDARY OUTCOME: 1. The ratio of the participants who have a moderate or severe symptom on the 5th day after taking the test drugs. ; 2. The sum of the symptom scores during the 5 days. ; 3. The ratio of the participants who have a severe symptom during the 5 days. ; 4. The ratio of the participants who have a moderate or severe nasal, pharyngeal, or tracheal symptom for 2 days or more during the 7 days. If some individual cold symptoms were evaluated as "moderate" before the treatment, we will check up on whether they will be severe for more than two days during seven days after the treatment. INCLUSION CRITERIA: Patients who satisfy all of the following criteria will be participated in this study. 1. Discomfort, pain, or scratchiness in the throat 2. The symptoms began on the day or the previous day of the visit. 3. Chillness 4. Without sweating 5. Catching a cold once at least within the past 3 years