Oseltamivir: A review of its use in influenza

• Published in: Drugs (New York, N.Y.) N.Y.), 2001, Vol.61 (2), p.263-283
• Main Authors: MCCLELLAN, Karen, PERRY, Caroline M
• Format: Article
• Language: English
• Subjects: Acetamides - pharmacology; Acetamides - therapeutic use; Adolescent; Adult; Aged; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiviral agents; Antiviral Agents - pharmacology; Antiviral Agents - therapeutic use; Biological and medical sciences; Child; Drug Resistance, Microbial; Enzyme Inhibitors - administration & dosage; Enzyme Inhibitors - therapeutic use; Humans; Influenza A virus - drug effects; Influenza B virus - drug effects; Influenza, Human - drug therapy; Influenza, Human - virology; Medical sciences; Middle Aged; Neuraminidase - antagonists & inhibitors; Oseltamivir; Pharmacology. Drug treatments
• ISSN: 0012-6667; 1179-1950
• DOI: 10.2165/00003495-200161020-00011

Oseltamivir is a prodrug of oseltamivir carboxylate (Ro 64-0802, GS4071), a potent and selective inhibitor of the neuraminidase glycoprotein essential for replication of influenza A and B viruses. Studies in volunteers with experimental human influenza A or B showed that administration of oral oseltamivir 20 to 200 mg twice daily for 5 days reduced both the quantity and duration of viral shedding compared with placebo. Subsequent assessment of the drug at a dosage of 75 mg twice daily for 5 days in otherwise healthy adults with naturally acquired febrile influenza showed that oseltamivir reduced the duration of the disease by up to 1.5 days and the severity of illness by up to 38% compared with placebo when initiated within 36 hours of symptom onset (earlier initiation of therapy was associated with faster resolution). The incidence of secondary complications and the use of antibacterials were also reduced significantly in oseltamivir recipients. A liquid formulation of oseltamivir (2 mg/kg twice daily for 5 days) has been shown to be effective in the treatment of children with influenza, and data presented in abstracts suggest that the drug may also be of use in high-risk populations such as the elderly or those with chronic cardiac or respiratory disease. In addition to treatment efficacy, the drug has demonstrated efficacy when used for seasonal or household prophylaxis. Oral oseltamivir (75 mg once or twice daily for 6 weeks) during a period of local influenza activity significantly prevented the development of naturally acquired influenza by >70% compared with placebo in unvaccinated otherwise healthy adults. The drug also demonstrated efficacy when used adjunctively in previously vaccinated high-risk elderly patients (92% protective efficacy). Short term administration of oseltamivir (75 mg once daily for 7 days) may significantly reduce the risk of illness in household contacts of infected persons when administered within 48 hours of symptom onset in the infected person. Oseltamivir 75 mg twice daily for 5 days was well tolerated in clinical trials in healthy adults and high-risk patients, with nausea and vomiting being the most commonly reported events. Gastrointestinal events were mild and transient and both nausea and vomiting were less likely when oseltamivir was taken with food. Oseltamivir is a well tolerated orally active neuraminidase inhibitor which significantly reduces the duration of symptomatic illness and hastens the return to normal l