Fabiflu Special Precautions

Favipiravir is a drug in which the use is considered only when there is an outbreak of novel or re-emerging influenza virus infections in which other anti-influenza virus agents are not effective or insufficiently effective, and the government decides to use the drug as a countermeasure against such influenza viruses. When administering the drug, obtain the latest information including government's direction of countermeasures against such influenza viruses, and prescribe only to appropriate patients.
Favipiravir is not effective against bacterial infections (See following text).
Careful Administration: Favipiravir should be administered with care in the following patients: Patients with history of abnormalities in metabolism of uric acid or having gout. (Blood uric acid level may increase, and symptoms may get aggravated.) (See "Adverse Reactions".)
Important Precautions: No clinical study has been conducted to examine the efficacy and safety of Favipiravir with the approved dosage. The approved dosage was estimated based on the results of a placebo-controlled phase I/II clinical study in patients with influenza virus infection and the pharmacokinetic data from Japanese and overseas studies. Increase of plasma level of favipiravir has been reported in patients with liver function impairment in pharmacokinetic study conducted outside of Japan (See "Pharmacology: Pharmacodynamics: CLINICAL STUDIES and Pharmacokinetics under Actions").
Regardless of the administration or the type of anti-influenza virus agents, cases of abnormal behavior have been reported in patients with influenza virus infection (See "Clinically significant adverse reactions under Adverse Reactions"). As a preventive approach to accidents such as fall due to abnormal behavior, patients/their family should be instructed that, abnormal behavior may occur, and when patients are treated at home, guardians and others should take preventive measures against accidents such as fall for at least 2 days after onset of fever. Severe abnormal behavior leading to fall accidents have been reported more in male children of school age and minors, and it has been known that the symptoms are more likely to occur within 2 days after onset of fever.
Influenza virus infection may be complicated with bacterial infections or may be confused with influenza-like symptoms. In case of bacterial infection or suspected to be bacterial infection, appropriate measures should be taken, such as administration of anti-bacterial agents (See previous text).
Effects on ability to drive and use machines: No data are available.
Use in Children: Favipiravir has not been administered to children (See previous text).