Oseltamivir is the world's first orally effective influenza neuraminidase inhibitor (NAI) and a landmark drug in the field of influenza prevention and treatment, mainly used for the prevention and treatment of influenza virus infection.

1、 Drug name

Common name: Oseltamivir Phosphate

Product Name: TAMIFLU ® (Daffy) ®)

2、 Indications

Treatment of influenza: Used to treat acute, uncomplicated influenza A and B in patients aged 2 weeks and above, with symptoms occurring within 48 hours.

Influenza prevention: Used for post exposure or seasonal prevention of influenza A and B in patients aged 1 year and above.

Usage restrictions:

It cannot replace getting vaccinated against the flu every year.

Not applicable to end-stage renal disease patients who have not received dialysis.

When prescribing, reference should be made to the sensitivity and efficacy information of influenza virus drugs.

3、 Specifications and characteristics

Capsules: 75 milligrams.

4、 Main components

Active ingredient: Oseltamivir phosphate.

5、 Usage and dosage

Treating influenza:

Adults and adolescents (13 years old and above): 75mg, taken twice daily for 5 days.

Children (1-12 years old): Administer according to body weight (e.g. ≤ 15 kg, 30 mg, twice daily).

Children (2 weeks to<1 year old): 3 milligrams per kilogram, taken twice daily for 5 days.

Preventing influenza:

Adults and adolescents (13 years and older): 75 milligrams, once daily, at least 10 days after exposure, and up to 6 weeks during community outbreaks.

Children (1-12 years old): once daily based on weight, up to 10 days after exposure or up to 6 weeks during community outbreaks.

Individuals with low immune function: Prevention can last up to 12 weeks.

Administration method: It can be taken together with food or taken alone. Capsules can be swallowed as a whole or provide a suspension or temporary oral solution for those who cannot swallow.

6、 Dose adjustment (for patients with renal insufficiency)

Mild (creatinine clearance rate>60-90 mL/min): No adjustment required.

Moderate (>30-60 milliliters/minute): Reduce the therapeutic dose to 30 milligrams twice a day; Reduce the preventive dose to 30 milligrams once daily.

Severe (>10-30 mL/min): Reduce the therapeutic dose to 30 mg once daily; Reduce the preventive dose to 30 milligrams, once every other day.

End stage renal disease (ESRD) dialysis patients: dosage and dosing interval need to be adjusted. Please follow the doctor's advice for specific plans.

End stage renal disease (ESRD) non dialysis patients: Not recommended for use.

7、 Medication precautions

Medication timing: Treatment should begin within 48 hours of symptom onset; Prevention should start as soon as possible after exposure.

Omission treatment: If missed, it should be replenished as soon as possible. If it is less than 2 hours before the next dose, skip the missed dose and take the next dose according to the original plan. Do not take double the dose at once.

Vomiting treatment: If vomiting occurs shortly after taking the medication, it may be considered to take a supplementary dose. If vomiting occurs repeatedly or persists, consult a doctor.

Dysphagia: Prioritize the use of oral suspensions. In emergency situations, capsules can be opened and mixed with a small amount of sweet liquid for consumption.

8、 Medication for special populations

Children: Treatment is suitable for those aged ≥ 2 weeks; Prevention is applicable for ages ≥ 1. The safety and effectiveness have been confirmed.

Elderly people: Safety is similar to that of young adults, and there is no need for regular dose adjustments.

Pregnant women: Insufficient controlled studies. The existing epidemiological data does not show an increased risk of birth defects. We should weigh the pros and cons.

Breastfeeding women: Medications may enter breast milk in small amounts, but are considered to have a low likelihood of causing toxicity to infants. We should weigh the pros and cons.

Patients with liver dysfunction: mild to moderate without dose adjustment; The safety of severe cases has not been evaluated.

Patients with renal insufficiency: Dose adjustment must be made based on creatinine clearance rate .

9、 Adverse reactions

Common adverse reactions:

During treatment: nausea, vomiting, headache.

During the prevention period: nausea, vomiting, headache, and pain.

Serious Adverse Reactions (Rare but Cautious):

Severe skin/allergic reactions (such as Sjogren's syndrome, toxic epidermal necrolysis, erythema multiforme, angioedema, and anaphylactic shock).

Neuropsychiatric events (such as delirium, behavioral abnormalities, hallucinations, especially in children).

May exacerbate or mask bacterial infections.

10、 Contraindications

Those who are known to have severe hypersensitivity reactions to oseltamivir or any component of this product are prohibited from using it.

11、 Drug interactions

Attenuated live influenza vaccine: Within 2 weeks before or 48 hours after using oseltamivir, nasal attenuated live influenza vaccine should be avoided.

Inactivated influenza vaccine: can be administered at any time.

There is no clinically significant interaction with the following drugs: amoxicillin, acetaminophen, aspirin, cimetidine, commonly used antacids (magnesium/aluminum hydroxide, calcium carbonate), amantadine, rimantadine, warfarin.

12、 Storage method

Store at room temperature (15-30 ° C).

Keep out of reach of children. Please safely dispose of expired or no longer needed drugs.

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