What are the in-patient medications for Influenza B (flu) positive patients?

From the Guidelines

For patients with confirmed influenza B infection, antiviral medications are recommended, with oseltamivir (Tamiflu) being the first-line treatment. The standard adult dosage is 75 mg twice daily for 5 days, while children receive weight-based dosing (30-75 mg twice daily) 1. Treatment should ideally begin within 48 hours of symptom onset for maximum effectiveness, though it may still provide benefit when started later, especially in severely ill patients. Alternative medications include zanamivir (Relenza) 1. Supportive care is also important, including rest, adequate hydration, and fever control with acetaminophen or ibuprofen. Antiviral medications work by inhibiting viral replication, reducing symptom duration by 1-2 days, decreasing complication risk, and potentially reducing viral transmission. High-risk patients (elderly, pregnant women, young children, and those with chronic medical conditions) should be prioritized for treatment even if presenting after the 48-hour window.

Some key points to consider when treating patients with influenza B include:

• The importance of starting treatment as soon as possible, ideally within 48 hours of symptom onset 1
• The use of oseltamivir as the first-line treatment, due to its effectiveness and the high sensitivity of currently circulating influenza virus strains to this medication 1
• The consideration of alternative medications, such as zanamivir, if oseltamivir is not suitable 1
• The importance of supportive care, including rest, hydration, and fever control, in addition to antiviral treatment

It's worth noting that the evidence from 1 is outdated and does not reflect the current recommendations for the treatment of influenza B. The more recent study 1 provides the most up-to-date guidance on the use of antiviral medications for the treatment of influenza B.

From the FDA Drug Label

Among the 81 subjects treated with RAPIVAB, the median age was 7. 5 years; 52% were male; 60% were infected with influenza A virus, 33% were infected with influenza B virus, and 6% were co-infected with influenza A and B viruses. Insufficient numbers of subjects infected with influenza B virus were enrolled to determine efficacy of RAPIVAB in this influenza type. RELENZA is a prescription medicine used to: • treat the flu (influenza A and B virus) in people who are aged 7 years and older who have had flu symptoms for no more than 2 days

The efficacy of peramivir (IV) for the treatment of influenza B is unknown due to insufficient numbers of subjects infected with influenza B virus in the study.

• Zanamivir (INH) is approved for the treatment of influenza A and B virus in people aged 7 years and older. However, no conclusion can be drawn about the efficacy of peramivir (IV) in patients with flu B positive from the provided drug labels 2.

From the Research

Patient Medication for Flu B Positive

• The treatment of influenza B positive patients can be managed with antiviral medications such as oseltamivir, zanamivir, and others 3, 4, 5, 6, 7.
• Oseltamivir is a neuraminidase inhibitor that can decrease the median duration of influenza-related symptoms by approximately 1 day if initiated within 48 hours of the onset of symptoms of influenza 4, 5.
• The recommended dosage of oseltamivir is 75 mg twice daily by mouth for five days, but there is no significant benefit in doubling the dose or extending treatment beyond five days in most patient populations 3.
• In critically ill patients, the use of oseltamivir may be beneficial, but the evidence is limited, and further research is needed to assess its efficacy in this population 6.
• In infants with influenza B, oseltamivir treatment can shorten the duration and severity of symptoms, although the clinical effectiveness may be greater against influenza A than against influenza B infections 7.

Antiviral Medications

• Oseltamivir, zanamivir, and other neuraminidase inhibitors are effective in treating influenza A and B infections 4, 5, 6.
• These medications work by blocking the influenza neuraminidase enzyme, preventing the cleavage of sialic acid residues, and reducing viral infectivity 4, 5.
• The most common adverse effects of oseltamivir include nausea, vomiting, and headache, while zanamivir can cause upper respiratory tract symptoms and bronchospasm in patients with asthma or chronic obstructive pulmonary disease 4, 5.

Treatment Guidelines

• Treatment with oseltamivir or other antiviral medications should be initiated within 48 hours of the onset of symptoms for optimal effectiveness 3, 4, 5.
• The treatment duration is typically five days, but may be extended in critically ill patients or those with severe influenza infections 3, 6.
• The selection of antiviral medication and treatment duration should be individualized based on patient factors, such as age, underlying health conditions, and severity of illness 6, 7.