Analyse the time of flu symptom relief in adults with uncomplicated acute influenza,to evaluate the antiviral effects of high and low doses of GP681 tablets, and explore the optimal dose for phase III clinical trials.

Inclusion Criteria:

• Positive Influenza rapid antigen test;

• Fever (axillary temperature ≥37.3℃) or the axillary temperature ≥37.3℃ after taking the medicine for more than 4 hours;

• At least one systemic symptom and respiratory symptom related to a moderate or above influenza virus infection:

  1. Systemic symptoms: headache, fever or chills, muscle or joint aches, fatigue;
  2. Respiratory system symptoms: cough, sore throat, nasal congestion.

• Time of disease symptoms ≤48h

Exclusion Criteria:

• Diagnosed as severe influenza patient ;
• Known history of dysphagia or any gastrointestinal disease that affects drug absorption (including but not limited to reflux esophagitis, chronic diarrhea, inflammatory bowel disease, intestinal tuberculosis, gastrinoma, short bowel syndrome, stomach After subtotal resection, etc.);
• Have used anti-influenza virus drugs (oseltamivir, zanamivir, peramivir, favipiravir, abidol, baloxavir dipivoxil, amantadine, or diamond) within 2 weeks before screening Ethylamine, etc.);
• Acute respiratory infections, otitis media, sinusitis or other infectious diseases such as bronchitis, pneumonia, tuberculosis, etc. occurred within 2 weeks before screening, and are in the acute stage;
• Patients who also suffer from bacterial or viral infections and need systemic antibacterial or antiviral therapy