Directions for Use: For internal use, to be taken on an empty stomach. Single dose amount: Children 2 - 7 years, 50 mg; 7 – 12 years, 100 mg; 12 – adult, 200 mg (1 - 200 mg capsule, 2 – 100 mg capsules, or 4 - 50 mg capsules). For non-specific prophylaxis: During direct contact with patients with influenza or RSV, children 2 – 7, 50 mg; children 7 – 12, 100 mg; 12 to adult, 200 mg, once a day for 10 to 14 days. During influenza or other RSV epidemics, or in order to prevent exacerbation of chronic bronchitis, or recurrent herpes infection, the dosage is children 2 – 7, 50 mg; children 7 – 12, 100 mg; and over 12 to adult, 200 mg, twice a week for three weeks. For SARS prophylaxis (during contact with SARS patients), the dosage for children over 12 – adult is 200 mg once a day; for children from 7 to 12, 100 mg, taken before food, once a day for 12 – 14 days. For prophylaxis against postoperative complications: children 2 – 7, 50 mg; children 7 – 12, 100 mg; children over 12 – adult, 200 mg 48 hours before the procedure, then from 2 to 5 days after the procedure. For treatment of illness: For influenza, or other uncomplicated RSV, children 2 – 7, 50 mg; children 7 – 12, 100 mg, and children over 12 and adults, 200 mg, 4 times a day (every 6 hours) for 5 days. For influenza with complications (bronchitis, pneumonia), children 2 – 7, 50 mg; children 7 – 12, 100 mg; children over 12 and adults, 200 mg, 4 times a day (every 6 hours) for 5 days, then one dose per week for the next four weeks. For Severe Acute Respiratory Syndrome (SARS), in children over 12 and adults, 200 mg twice a day for 8 – 10 days. For chronic bronchitis or herpes-type infections, in children 2 – 7 years, 50 mg; children 7 – 12, 100 mg; children over 12 and adults, 200 mg 4 times a day (every 6 hours) for 5 – 7 days; thereafter, one dose twice a week for the next 4 weeks. For treatment of acute intestinal infections of the rotavirus-type, in children over 2 years old, give 50 mg; children 7 – 12, 100 mg; and children over 12, 200 mg, four times a day (every 6 hours) for 5 days.

An umifenovir (arbidol) concentration of 20μg/ml was required to achieve a 50% reduction in virus proliferation and hemagglutinin levels.