What is the prescription guideline for Oseltamivir (Tamiflu) for influenza?

From the Guidelines

Tamiflu (oseltamivir) is recommended for treating influenza in adults and children, with a standard adult dosage of 75 mg twice daily for 5 days, and weight-based dosing for children, as outlined in the most recent guidelines 1. The dosage for children is based on their weight, with the following recommendations:

• For children weighing ≤15 kg, the dose is 30 mg twice daily
• For children weighing >15 kg and up to 23 kg, the dose is 45 mg twice daily
• For children weighing >23 kg and up to 40 kg, the dose is 60 mg twice daily
• For children weighing >40 kg, the dose is 75 mg twice daily It's essential to start treatment as soon as possible after symptoms appear, and to complete the full course even if symptoms improve, as this can help reduce the duration of flu symptoms by about 1-2 days and potentially decrease complications 1. Some key points to consider when prescribing oseltamivir include:
• Common side effects include nausea and vomiting, which can be reduced by taking it with food
• Oseltamivir works by inhibiting the viral neuraminidase enzyme, preventing the release of new virus particles from infected cells
• People with kidney disease may need dose adjustments, and pregnant women should discuss risks and benefits with their healthcare provider
• Oseltamivir is not a substitute for the flu vaccine and doesn't treat bacterial infections or other viral illnesses
• The most recent guidelines recommend oseltamivir for treatment of influenza in children as young as 2 weeks, and support its use in pediatric patients with severe influenza, including hospitalized patients 1.

From the FDA Drug Label

The efficacy of oseltamivir phosphate in preventing naturally occurring influenza illness has been demonstrated in three seasonal prophylaxis (community outbreak) clinical trials and one post-exposure prophylaxis trial in household contacts Oseltamivir phosphate 75 mg once daily taken for 42 days during a community outbreak reduced the incidence of laboratory-confirmed clinical influenza from 5% (25/519) for the placebo group to 1% (6/520) for the oseltamivir phosphate group In a post-exposure prophylaxis trial in household contacts (aged 13 years or older) of an index influenza case, oseltamivir phosphate 75 mg once daily or placebo taken orally was administered within 48 hours of onset of symptoms in the index case and continued for 7 days Take oseltamivir phosphate for oral suspension exactly as your healthcare provider tells you to. Take oseltamivir phosphate for oral suspension with food or without food If you miss a dose of oseltamivir phosphate for oral suspension, take it as soon as you remember. If it is 2 hours or less before your next dose, do not take the missed dose. Take your next dose of oseltamivir phosphate for oral suspension at your scheduled time

The prescription guideline for Oseltamivir (Tamiflu) for influenza is to take 75 mg once daily for the prevention of influenza, and treatment should be started within 48 hours of onset of symptoms. For treatment, the dosage is 75 mg twice daily for 5 days. It is recommended to take oseltamivir phosphate for oral suspension with food or without food, and if a dose is missed, it should be taken as soon as possible, unless it is 2 hours or less before the next scheduled dose 2.

From the Research

Prescription Guideline for Oseltamivir (Tamiflu) for Influenza

• The recommended dosage of oseltamivir for the treatment of uncomplicated influenza in patients two weeks of age or older who have been symptomatic for no more than two days is 75 mg twice daily by mouth for five days 3, 4.
• For children, a liquid formulation of oseltamivir (2 mg/kg twice daily for 5 days) has been shown to be effective in the treatment of influenza 3.
• Oseltamivir is most effective when initiated within 36 hours of symptom onset, with earlier initiation of therapy associated with faster resolution of symptoms 3, 5.
• The drug has demonstrated efficacy when used for seasonal or household prophylaxis, with oral oseltamivir (75 mg once or twice daily for 6 weeks) preventing the development of naturally acquired influenza by >70% compared with placebo in unvaccinated otherwise healthy adults 3.
• Oseltamivir may increase survival when used within five days of symptom onset in influenza H1N1-infected patients who require ICU admission 4.
• There is no benefit in starting treatment more than 48 hours after symptom onset in hospitalized general medicine patients or outpatients infected with either H1N1 or other influenza strains, or in doubling the dose of oseltamivir in hospitalized patients or outpatients 4.

Special Considerations

• Oseltamivir is well tolerated in clinical trials in healthy adults and high-risk patients, with nausea and vomiting being the most commonly reported events 3, 6, 5.
• Gastrointestinal events are mild and transient and both nausea and vomiting are less likely when oseltamivir is taken with food 3, 5.
• The use of oseltamivir in patients with chronic cardiac or respiratory disease has been shown to be effective in reducing the duration of acute febrile illness 6.