Administration and Storage of Tamiflu
Tamiflu is available in 75 mg, 45 mg, and 30 mg capsules and a liquid form for patients who may have difficulty swallowing capsules.1
Taking Tamiflu With Other Medications1
Information derived from pharmacology and pharmacokinetic studies of oseltamivir suggests that clinically significant drug interactions are unlikely.
Oseltamivir is extensively converted to oseltamivir carboxylate by esterases, located predominantly in the liver.
Drug interactions involving competition for esterases have not been extensively reported in literature. Low protein binding of oseltamivir and oseltamivir carboxylate suggests that the probability of drug displacement interactions is low.
The concurrent use of Tamiflu and live attenuated influenza vaccine (LAIV) intranasal has not been evaluated. However, because of the possibility for interference between these products, LAIV should not be given within 2 weeks before or 48 hours after administration of Tamiflu, unless medically indicated. The concern about possible interference arises from the potential for antiviral drugs to inhibit replication of live virus. Trivalent inactivated influenza vaccine can be administered at any time relative to use of Tamiflu.1
Storing Tamiflu
- Refrigeration: Stable for 5 weeks (35 days) when stored in a refrigerator at 2° to 8°C (36° to 46°F).
- Room Temperature: Stable for five days (5 days) when stored at room temperature, 25°C (77°F).
Alternatively, store constituted liquid Tamiflu for up to 10 days at 77°F (25°C). As with all medications, keep out of the reach of children.1
Administering Tamiflu Liquid1
An oral dosing dispenser with 30 mg, 45 mg, and 60 mg graduations is provided with the oral suspension; the 75 mg dose can be measured using a combination of 30 mg and 45 mg.
Tamiflu can be mixed by a pharmacist extemporaneously when needed. Learn more about extemporaneous preparation.
Next Step: Learn about treating influenza in children with Tamiflu ›
Did you know?
The CDC recommends antivirals in addition to yearly vaccination and preventive measures as part of an effective influenza management plan.30, 31
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.
Efficacy of TAMIFLU in patients who begin treatment after 48 hours of symptoms has not been established.
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).
There is no evidence for efficacy of TAMIFLU in any illness caused by agents other than influenza viruses Types A and B.
Influenza viruses change over time. Emergence of resistance mutations could decrease drug effectiveness. Other factors (for example, changes in viral virulence) might also diminish clinical benefits of antiviral drugs. Prescribers should consider available information on influenza drug susceptibility patterns and treatment effects when deciding whether to use Tamiflu.
Important Safety Information
1TAMIFLU is contraindicated in patients who have had severe allergic reactions such as anaphylaxis or serious skin reactions such as toxic epidermal necrolysis, Stevens-Johnson syndrome, or erythema multiforme to any component of TAMIFLU.
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. Tamiflu should be stopped and appropriate treatment instituted if an allergic-like reaction occurs or is suspected.
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.
Serious bacterial infections may begin with influenza-like symptoms or may co-exist with or occur as complications during the course of influenza. TAMIFLU has not been shown to prevent such complications.
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.
The concurrent use of TAMIFLU with live attenuated influenza vaccine (LAIV) intranasal has not been evaluated. However, because of the potential for interference between these products, LAIV should not be administered within 2 weeks before or 48 hours after administration of TAMIFLU, unless medically indicated.
Adverse events that occurred more frequently in patients treated with TAMIFLU than in patients taking placebo and occurred in ≥2% of patients were (TAMIFLU %, placebo %):
- Treatment in adults - nausea (10%, 6%), vomiting (9%, 3%), bronchitis (2%, 2%)
- Treatment in pediatrics - vomiting (15%, 9%), abdominal pain (5%, 4%), epistaxis (3%, 3%), ear disorder (2%, 1%)
- Prophylaxis of adults - headache (18%, 18%), nausea (7%, 3%), diarrhea (3%, 2%), vomiting (2%, 1%), abdominal pain (2%, 1%)
- Prophylaxis of pediatrics - vomiting (10%, 2%), abdominal pain (3%, 0%), nausea (4%, 1%)
Please see the TAMIFLU full Prescription Information for complete safety information.
