Antiflu Capsule, Syrup

Antiflu is a prodrug of oseltamivir carboxylate. Antiflu carboxylate inhibits neuraminidase (sialidase), a viral surface enzyme which is responsible for the replication and infectivity of influenza virus A and B, thereby preventing the release of viruses from infected cells.


Antiflu is used for prevention of flu (influenza) in adults and adolescents aged 13 years and over who have been in contact with someone diagnosed with flu; treatment of flu (influenza) in adults and in children over one year of age when the influenza virus is circulating in the community

Antiflu is also used to associated treatment for these conditions: Flu caused by Influenza, Influenza A Virus Infection, Influenza A, Influenza B, Influenza Type B

Trade Name Antiflu
Generic Oseltamivir
Other Names Oseltamivir, Oséltamivir, Oseltamivirum
Weight 75mg, 45mg
Type Capsule, Syrup
Formula C16H28N2O4
Weight Average: 312.4045
Monoisotopic: 312.204907394
Protein binding

The binding of the active oseltamivir carboxylate metabolite to human plasma protein is negligible at approximately 3 % while the binding of oseltamivir to human plasma protein is 42%, which is insufficient to cause significant displacement-based drug interactions.

Therapeutic Class Respiratory viral infections (Influenza)
Manufacturer Cipla Limited, Aristopharma Ltd
Available Country India, Bangladesh
Last Updated: June 23, 2021 at 9:00 am


Antiflu dosage

Antiflu Phosphate may be taken with or without food. However, when taken with food, tolerability may be enhanced in some patients.Standard oral dose for the treatment of influenza: 

  • Adults and Adolescents: The recommended oral dose of Antiflu for treatment of influenza in adults and adolescents 13 years and older is 75 mg twice daily for 5 days. Treatment should begin within 2 days of onset of symptoms of influenza.
  • Pediatric patients: The safety and efficacy of Antiflu for prophylaxis of influenza in pediatric patients younger than 13 years of age have not been established.

Recommended oral dose for the treatment of influenza:

  • For prophylaxis of influenza in adults and adolescents 13 years and older following close contact with an infected individual: 75 mg once daily for at least 7 days. Therapy should begin within 2 days of exposure.
  • For prophylaxis during a community outbreak of influenza: 75 mg once daily. Safety and efficacy have been demonstrated for up to 6 weeks. The duration of protection lasts for as long as dosing is continued.

May be taken with or without food. May be taken with meals to reduce GI discomfort. Cap may be opened & mixed with sweetened food products eg chocolate syr, sweetened condensed milk, apple sauce or yogurt. Swallow mixture immediately after preparation.

Side Effects

The most frequently reported adverse events are nausea and vomiting. These events generally of mild to moderate degree and usually are occurred on the first 2 days of administration. Additional adverse events occurring in <1% of patients receiving Antiflu for treatment include unstable angina, anemia, pseudomembranous colitis, humerus fracture, pneumonia, pyrexia, and peritonsillar abscess.


There is no evidence for efficacy of Antiflu Phosphate in any illness caused by agents other than influenza viruses Types A and B. Efficacy of Antiflu Phosphate in patients who begin treatment after 40 hours of symptoms has not been established.


Information derived from pharmacology and pharmacokinetic studies of Antiflu suggests that clinically significant drug interactions are unlikely. Co-administration with amoxicillin does not alter plasma levels of either compound.

Food Interaction

  • Take with or without food. Co-administration with food does not affect pharmacokinetics but may enhance tolerability.

Volume of Distribution

The mean volume of distribution at steady state of the oseltamivir carboxylate ranges approximately between 23 and 26 liters in humans, a volume that is roughly equivalent to extracellular body fluid. Since neuraminidase activity is extracellular, oseltamivir carboxylate distributes to all sites of influenza virus spread.

Half Life

Plasma concentrations of oseltamivir declined with a half-life of 1 to 3 hours in most subjects after oral administration, although plasma concentrations of oseltamivir carboxylate declined with a half-life of 6 to 10 hours in most subjects after oral administration.


Renal clearance (18.8 l/h) of the drug exceeds glomerular filtration rate (7.5 l/h) indicating that tubular secretion occurs in addition to glomerular filtration.

Pregnancy & Breastfeeding use

Pregnancy Category C: There are insufficient human data upon which to base an evaluation of risk of Antiflu Phosphate to the pregnant woman or developing fetus.

Nursing Mothers: It is not known whether oseltamivir or oseltamivir carboxylate is excreted in human milk. Antiflu Phosphate should, therefore, be used only if the potential benefit for the lactating mother justifies the potential risk to the breast-fed infant.


Antiflu is contraindicated in patients with known hypersensitivity to any of the components of the product.

Special Warning

Hepatic Impairment: The safety and pharmacokinetics in patients with hepatic impairment have not been evaluated.

Renal Impairment: Dose adjustment is recommended for patients with a serum creatinine clearance <30 mL/min.

Geriatric Use: The safety of Antiflu Phosphate has been established in clinical studies.

Pediatric Use: The safety and efficacy of Antiflu Phosphate in pediatric patients younger than 1 year of age have not been studied. Antiflu Phosphate is not indicated for either treatment or prophylaxis of influenza in pediatric patients younger than 1 year of age.

Acute Overdose

At present there has been no experience of over dose. Single dose of up to 1000 mg of Antiflu have been associated with nausea and/or vomiting.

Storage Condition

Store at 25°C. Reconstituted susp: Store between 2-8°C for up to 17 days or at 25°C for up to 10 days. Do not freeze.

Antiflu contains Oseltamivir see full prescribing information from innovator Monograph