Oseltamivir phosphate CAS 204255-11-8 Whie Powder

Oseltamivir phosphate More Info

Oseltamivir phosphate, commonly known by its brand name Tamiflu, is an antiviral medication primarily used for the treatment and prevention of influenza types A and B. It is classified as a neuraminidase inhibitor, which plays a critical role in limiting the spread of the virus within the body.

Mechanism of Action

Oseltamivir functions as a prodrug, which means it is converted into its active form, oseltamivir carboxylate, after administration. This conversion occurs rapidly through hydrolysis by hepatic esterases. The active metabolite selectively inhibits the neuraminidase enzyme found on the surface of influenza viruses. By blocking this enzyme, oseltamivir prevents the release of new viral particles from infected cells, thereby reducing viral replication and limiting the severity and duration of flu symptoms when administered within 48 hours of symptom onset

Applications

Treatment of Influenza: Effective in adults and children (over 2 weeks old) who present flu symptoms within two days.
Prophylaxis: Used to prevent influenza in individuals who have been exposed to the virus or during outbreaks.

Routes of Administration

Oseltamivir is available in several oral formulations:
Capsules: 30 mg, 45 mg, and 75 mg.
Powder for Oral Suspension: 6 mg/mL.

Safety and Side Effects

While oseltamivir is generally well-tolerated, it may cause side effects, including:
Common Side Effects: Nausea, vomiting, headache, and abdominal pain.
Serious Side Effects: Allergic reactions (e.g., rash, difficulty breathing), neuropsychiatric events (e.g., confusion, hallucinations), and skin reactions (e.g., Stevens-Johnson syndrome) have been reported but are rare.

Pharmacokinetics

The pharmacokinetics of oseltamivir are characterized by:
Absorption: Rapidly absorbed from the gastrointestinal tract with at least 75% of an oral dose reaching systemic circulation as oseltamivir carboxylate.
Distribution: Steady-state plasma concentrations are achieved within 2–3 days when taken twice daily.
Excretion: Primarily eliminated through renal pathways; renal impairment may necessitate dosage adjustments.