Generic Name: Oseltamivir Brand Name(s): Generics only. No brands available.

Uses

What is Oseltamivir used for?

Oseltamivir is used to treat symptoms caused by the flu virus (influenza). It helps make the symptoms (such as stuffy nose, cough, sore throat, fever/chills, aches, tiredness) less severe and shortens the recovery time by 1-2 days.

This medication may also be used to prevent the flu if you have been exposed to someone who already has the flu (such as a sick household member) or if there is a flu outbreak in the community. Talk to your doctor for more details.

This medication works by stopping the flu virus from growing. It is not a substitute for the flu vaccine.

How should I take Oseltamivir?

Take this medication by mouth with or without food. You may take it with food or milk to minimize stomach upset. Take this medication as soon as flu symptoms appear or as soon as possible after you have been exposed to the flu. Oseltamivir works best if you start taking it within 2 days of either of these events.

If you have the flu, take oseltamivir as directed by your doctor, usually twice a day for 5 days.

To prevent the flu, take oseltamivir as directed by your doctor, usually once a day for at least 10 days. Follow your doctor’s instructions for how long to take this medicine.

The dosage is based on your medical condition, kidney function, and response to treatment. In children the dosage is also based on weight.

If you cannot swallow the capsules, ask your doctor or pharmacist about the liquid suspension form of oseltamivir. If the liquid is not available and if directed by your doctor or pharmacist, you may open up the capsule and mix the contents with a small amount of sweetened liquid (such as regular/sugar-free chocolate syrup, corn syrup, caramel topping, or light brown sugar dissolved in water). Stir the mixture and take the entire dose.

This medication works best when the amount of medicine in your body is kept at a constant level. Therefore, take this drug at evenly spaced intervals at the same time(s) every day. Continue to take it for the full time prescribed. Stopping the medication too early may allow the virus to continue to grow, which may result in a relapse of the infection or failure to protect you from the flu.

Tell your doctor if your condition persists or worsens or if new symptoms appear.

How do I store Oseltamivir?

Store the capsules at room temperature away from moisture and heat. Store the liquid in the refrigerator but do not freeze. Throw away any unused liquid after 17 days. The liquid may also be stored at cool room temperature for up to 10 days.

There may be different brands of Oseltamivir that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Oseltamivir down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Oseltamivir?

Before taking oseltamivir, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease (including dialysis treatment).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This medication passes into breast milk but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.

Is it safe during pregnancy or breast-feeding?

There are no adequate studies in women for determining risk when using this Oseltamivir during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Oseltamivir. Oseltamivir is pregnancy risk category C according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk,
  • B=No risk in some studies,
  • C=There may be some risk,
  • D=Positive evidence of risk,
  • X=Contraindicated,
  • N=Unknown

Side effects

What side effects can occur from Oseltamivir?

Nausea and vomiting may occur. If either of these effects persist or worsen, notify your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

The flu itself or oseltamivir may rarely cause serious mental/mood changes. This may be more likely in children. Tell your doctor right away of any signs of unusual behavior, including: confusion, agitation, self-injury.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.

Interactions

What drugs may interact with Oseltamivir?

Tell your doctor if you have received flu vaccine in the nose within 2 weeks before treatment with this medication. This medication may lower your protection from flu vaccine given in the nose. Wait at least 2 days after ending treatment with this medication before receiving flu vaccine given in the nose.

Oseltamivir may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with Oseltamivir?

Oseltamivir may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Oseltamivir?

Oseltamivir may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this Oseltamivir.

What is the dose of Oseltamivir for an adult?

Usual Adult Dose for Influenza

75 mg orally twice a day for 5 days

Use: For the treatment of acute, uncomplicated influenza infection in patients symptomatic no more than 48 hours

Usual Adult Dose for Influenza Prophylaxis

After close contact with an infected individual: 75 mg orally once a day for at least 10 days

During a community outbreak of influenza: 75 mg orally once a day

Comments:

-Therapy should begin within 48 hours of exposure.

-Safety and efficacy have been established for up to 6 weeks in immunocompetent patients; duration of protection lasts as long as dosing is continued.

-Safety has been established for up to 12 weeks in immunocompromised patients.

Renal Dose Adjustments

Adults:

Influenza Treatment:

-Mild renal dysfunction (CrCl greater than 60 to 90 mL/min): 75 mg orally twice a day

-Moderate renal dysfunction (CrCl greater than 30 to 60 mL/min: 30 mg orally twice a day

-Severe renal dysfunction (CrCl greater than 10 to 30 mL/min): 30 mg orally once a day

-ESRD not on dialysis (CrCl 10 mL/min or less): Not recommended.

Duration of therapy: 5 days

Influenza Prophylaxis:

-Mild renal dysfunction (CrCl greater than 60 to 90 mL/min): 75 mg orally once a day

-Moderate renal dysfunction (CrCl greater than 30 to 60 mL/min: 30 mg orally once a day

-Severe renal dysfunction (CrCl greater than 10 to 30 mL/min): 30 mg orally every other day

-ESRD not on dialysis (CrCl 10 mL/min or less): Not recommended.

Duration of prophylaxis: Same as recommended with normal renal function

Liver Dose Adjustments

Mild to moderate liver dysfunction (Child-Pugh score 9 or less): No adjustment recommended.

Dialysis

Adults:

Influenza Treatment:

-ESRD on hemodialysis (CrCl 10 mL/min or less): 30 mg orally after each hemodialysis cycle

-ESRD on CAPD (CrCl 10 mL/min or less): 30 mg orally as a single dose immediately after a dialysis exchange

Duration of therapy: Should not exceed 5 days, assuming 3 hemodialysis sessions are performed in the 5-day period

Comments: Treatment can be started immediately if influenza symptoms develop during the 48 hours between hemodialysis sessions; however, the post-hemodialysis dose should still be administered independently of time of initial dose administration.

Influenza Prophylaxis:

-ESRD on hemodialysis (CrCl 10 mL/min or less): 30 mg orally after alternate hemodialysis cycles

-ESRD on CAPD (CrCl 10 mL/min or less): 30 mg orally once a week immediately after dialysis exchange

Duration of prophylaxis: Same as recommended with normal renal function

Comments: An initial dose can be administered before the start of hemodialysis.

Other Comments

Administration advice:

-Start therapy within 48 hours of onset of influenza symptoms or after close contact with an infected individual.

-May administer without regard to food; administration with food may improve tolerability in some patients.

-The oral suspension is preferred for patients unable to swallow capsules; use an oral dosing device that measures the appropriate volume in mL.

-Shake the oral suspension (commercial or emergency compounded) well before each use; discard unused portions after the completion of therapy.

-Consult the manufacturer product information regarding missed doses.

Storage requirements:

-Constituted oral suspension: Store under refrigeration for up to 17 days at 2C to 8 C (36F to 46F), freezing should be avoided; or store for up to 10 days at controlled room temperature, 25C (77F) with excursions permitted to 15C to 30C (59F to 86F).

-Emergency compounded oral suspension: Stable for 35 days when stored refrigerated at 2C to 8 C (36F to 46F) or 5 days when stored at room temperature, 25C (77F).

Reconstitution/preparation techniques:

-The manufacturer product information should be consulted for preparation of the oral suspension; it should be constituted by the pharmacist prior to dispensing to the patient.

-If the oral suspension is unavailable: The capsules may be opened and mixed with sweetened liquids such as chocolate syrup (regular or sugar-free), corn syrup, caramel topping, or light brown sugar (dissolved in water).

-If the appropriate capsule strengths are not available to mix with sweetened liquids and the oral suspension is unavailable: An emergency supply of oral suspension may be compounded from the 75 mg capsules.

During emergency situations only:

-If commercially manufactured oral suspension is not available, emergency compounded oral suspension (6 mg/mL), enough for 1 patient’s treatment for 5 days or prophylaxis for 10 days, may be prepared from the 75 mg capsules as follows:

  1. Determine the dose of oseltamivir for the patient then determine the total volume of oral suspension necessary to be compounded; if the dose is between listed doses, total volume of oral suspension to compound should default to the next greater dose listed.

-Dose of 15 mg or less: 37.5 mL total volume

-Dose of 30 mg: 75 mL total volume

-Dose of 45 mg: 100 mL total volume

-Dose of 60 mg: 125 mL total volume

-Dose of 75 mg: 150 mL total volume

  1. Determine the number of 75 mg capsules (includes overage to ensure delivery of all doses), amount of water, and amount of vehicle (Cherry Syrup, Ora-Sweet[R] SF, or simple syrup) necessary to prepare the total volume of compounded oral suspension (6 mg/mL).

-Total volume of 37.5 mL: 3 capsules (225 mg oseltamivir) plus 2.5 mL water plus 34.5 mL vehicle

-Total volume of 75 mL: 6 capsules (450 mg oseltamivir) plus 5 mL water plus 69 mL vehicle

-Total volume of 100 mL: 8 capsules (600 mg oseltamivir) plus 7 mL water plus 91 mL vehicle

-Total volume of 125 mL: 10 capsules (750 mg oseltamivir) plus 8 mL water plus 115 mL vehicle

-Total volume of 150 mL: 12 capsules (900 mg oseltamivir) plus 10 mL water plus 137 mL vehicle

  1. The procedure below should be followed to compound the oral suspension (6 mg/mL) from 75 mg capsules:

(a) Place the specified amount of water into a polyethyleneterephthalate (PET) or glass bottle.

(b) Carefully separate the capsule body and cap and place the contents of the number of 75 mg capsules needed into the PET or glass bottle.

(c) Gently swirl the suspension to ensure adequate wetting of the oseltamivir powder for at least 2 minutes.

(d) Slowly add the specified amount of vehicle to the bottle.

(e) Use a child-resistant cap to close the bottle and shake well for 30 seconds to completely dissolve the active drug and to ensure homogeneous distribution of the dissolved drug in the resulting suspension; the active drug (oseltamivir phosphate) is soluble in the specified vehicles but some of the inert ingredients are insoluble, causing the suspension.

General:

-Efficacy has not been established in patients starting therapy after 48 hours of symptoms.

-This drug is not a substitute for annual, early influenza vaccination as recommended by the US CDC Advisory Committee on Immunization Practices.

-Efficacy has not been established for any illness due to agents other than influenza viruses types A and B.

-As influenza viruses change over time, resistant or more virulent mutations may emerge and decrease the efficacy of antiviral drugs; available influenza drug susceptibility patterns and treatment effects should be considered when deciding whether to use this drug.

-The sorbitol content in one 75 mg dose of the oral suspension is 2 g, which exceeds the daily maximum limit for patients with hereditary fructose intolerance.

Monitoring:

-Psychiatric: For signs of abnormal behavior in patients with influenza

What is the dose of Oseltamivir for a child?

Usual Pediatric Dose for Influenza

2 weeks to less than 1 year: 3 mg/kg orally twice a day

1 to 12 years:

15 kg or less: 30 mg orally twice a day

15.1 through 23 kg: 45 mg orally twice a day

23.1 through 40 kg: 60 mg orally twice a day

40.1 kg or more: 75 mg orally twice a day

13 years or older: 75 mg orally twice a day

Duration of therapy: 5 days

Comments:

-For patients younger than 1 year, an appropriate dosing device that can accurately measure and administer small volumes should be provided.

Use: For the treatment of acute, uncomplicated influenza infection in patients (2 weeks or older) symptomatic no more than 48 hours

US CDC and American Academy of Pediatrics (AAP) Recommendations:

Preterm infants:

Postmenstrual age less than 38 weeks: 1 mg/kg orally twice a day

Postmenstrual age 38 through 40 weeks: 1.5 mg/kg orally twice a day

Postmenstrual age greater than 40 weeks: 3 mg/kg orally twice a day

Full-term infants 8 months or younger: 3 mg/kg orally twice a day

Infants 9 to 11 months: 3.5 mg/kg orally twice a day

Children 12 months or older:

15 kg or less: 30 mg orally twice a day

Greater than 15 to 23 kg: 45 mg orally twice a day

Greater than 23 to 40 kg: 60 mg orally twice a day

Greater than 40 kg: 75 mg orally twice a day

Comments:

-A pediatric infectious disease specialist should be consulted for extremely premature infants (postmenstrual age less than 28 weeks).

Usual Pediatric Dose for Influenza Prophylaxis

1 to 12 years:

15 kg or less: 30 mg orally once a day

15.1 through 23 kg: 45 mg orally once a day

23.1 through 40 kg: 60 mg orally once a day

40.1 kg or more: 75 mg orally once a day

13 years or older: 75 mg orally once a day

Duration of therapy:

-After close contact with an infected individual: 10 days

-During a community outbreak of influenza: May be continued for up to 6 weeks

Comments:

-Therapy should begin within 48 hours of exposure.

-The US FDA has not approved this use for patients younger than 1 year.

US CDC and AAP Recommendations:

Full-term infants younger than 3 months: Not recommended unless situation judged critical.

Full-term infants 3 to 8 months: 3 mg/kg orally once a day

Infants 9 to 11 months: 3.5 mg/kg orally once a day

Children 12 months or older:

15 kg or less: 30 mg orally once a day

Greater than 15 to 23 kg: 45 mg orally once a day

Greater than 23 to 40 kg: 60 mg orally once a day

Greater than 40 kg: 75 mg orally once a day

Precautions

Safety and efficacy for treatment of influenza have not been established in patients younger than 2 weeks. Safety and efficacy for prophylaxis of influenza have not been established in patients younger than 1 year.

How is Oseltamivir available?

Oseltamivir is available in the following dosage forms and strengths:

  • Oral capsule,
  • Oral powder for reconstitution.

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Oseltamivir, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

 

Hello Health Group does not provide medical advice, diagnosis or treatment.

Sources

Review Date: April 5, 2018 | Last Modified: April 5, 2018

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