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Pandemic Planning Toolkit A resource to assist your organization in preparing for pandemic influenza

TAMIFLU® (oseltamivir phosphate) has been studied only in strains of influenza that were circulating at the time. The magnitude of effect of TAMIFLU in treating and preventing novel strains of influenza, such as those that may be involved in a pandemic, cannot be predicted.

What is the TAMIFLU resistance profile?
Roche has both internal and external programs in place to monitor for emerging reports of viral resistance to TAMIFLU, and has been rigorous in its efforts to evaluate the emergence of such resistance.

Presently, there is no evidence to support that new strains of influenza will or will not develop resistance to Tamiflu.

What is the potential for TAMIFLU resistance?

  • As with any antiviral, the potential exists for an influenza virus to emerge with decreased sensitivity to a drug
  • TAMIFLU is a highly specific antiviral that acts by specific inhibition of the influenza virus neuraminidase44
  • The probability of resistance can be minimized by taking the prescribed dose for the full treatment duration

What is the incidence of resistance with TAMIFLU?

  • Data, collected from thousands of patients worldwide who were treated with TAMIFLU for seasonal influenza, indicate that the incidence of resistant virus is rare 45,46
  • In clinical studies, 1.3% (4/301) of adults and adolescents and 8.4% (9/105) of pediatric patients showed emergence of resistant virus
  • Resistance cannot develop unless there is influenza virus present; i.e., resistance cannot develop if a person who has a common cold is prescribed TAMIFLU inadvertently


Learn about the TAMIFLU dosage for seasonal flu.



 
FOOTNOTE
43. Data on file. Fact Sheet: Tamiflu and Resistance. Hoffmann-La Roche Inc., Nutley, NJ.
44. Nelson JD, McCracken GH. The Pediatric Infectious Disease Journal Newsletter: 2005.
45. Roberts N. Treatment of influenza with neuraminidase inhibitors: virological implications. Phil Trans R Soc Lond. 2001;356:1895-1897.
46. Yen et al, Antimicrobial Agents & Chemotherapy: October 2005. Vol.49;No.10. p4075-4084.
Indications

TAMIFLU is indicated for the treatment of uncomplicated influenza caused by viruses types A and B in patients 1 year and older who have been symptomatic for no more than 2 days.

TAMIFLU is also indicated for the prophylaxis of influenza in patients 1 year and older.

TAMIFLU is not a substitute for early and annual vaccination as recommended by the Centers for Disease Control's Advisory Committee on Immunization Practices (ACIP).

Prescribers should consider available information on influenza drug susceptibility patterns and treatment effects when deciding whether to use TAMIFLU.

Safety Information

There is no evidence for efficacy against any illness caused by agents other than influenza types A and B.

Treatment efficacy in subjects with chronic cardiac and/or respiratory disease has not been established. No difference in the incidence of complications was observed between the treatment and placebo groups in this population.

No information is available regarding treatment of influenza in patients at imminent risk of requiring hospitalization.

Efficacy of TAMIFLU has not been established in immunocompromised patients.

Safety and efficacy of repeated treatment or prophylaxis courses have not been studied.

Influenza can be associated with a variety of neurologic and behavioral symptoms, which can include events such as hallucinations, delirium and abnormal behavior, in some cases resulting in fatal outcomes. These events may occur in the setting of encephalitis or encephalopathy but can occur without obvious severe disease. There have been postmarketing reports (mostly from Japan) of delirium and abnormal behavior leading to injury, and in some cases resulting in fatal outcomes, in patients with influenza who were receiving TAMIFLU. Because these events were reported voluntarily during clinical practice, estimates of frequency cannot be made but they appear to be uncommon based on TAMIFLU usage data. These events were reported primarily among pediatric patients and often had an abrupt onset and rapid resolution. The contribution of TAMIFLU to these events has not been established. Patients with influenza should be closely monitored for signs of abnormal behavior. If neuropsychiatric symptoms occur, the risks and benefits of continuing treatment should be evaluated for each patient.

In postmarketing experience, rare cases of anaphylaxis and serious skin reactions, including toxic epidermal necrolysis, Stevens-Johnson syndrome and erythema multiforme, have been reported with TAMIFLU.

The most common adverse events reported >1% of patients treated with TAMIFLU and more commonly than in patients treated with placebo are:

  • Treatment of adult and pediatric patients - nausea, vomiting.
  • Prophylaxis of adult and pediatric patients - nausea, vomiting, abdominal pain.

Vaccination is considered the first line of defense against influenza.

Please see TAMIFLU full Prescribing Information for additional safety information.

 

Roche