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Relenza dosage: A detailed guide

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Doctors prescribe Relenza for treatment and prevention of the flu. It’s a powder that you inhale through your mouth from an oral inhaler once or twice per day.
Medically reviewed by Michael Rio, PharmD
Updated on

This article describes Relenza’s dosages and strength and gives details on how to use it. You’ll also find information on savings and coupon options for Relenza. If you want to know more about Relenza, talk with your doctor or pharmacist.

Relenza is a brand-name medication that comes as an oral inhaler. It isn’t available in a generic version. This article describes dosages of Relenza.

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Form and strength of Relenza

Relenza comes as follows:

  • Form: powder for use in an oral inhaler
  • Strength: 5-milligram (mg) blisters (disk-shaped packs of powder)

Dosage of Relenza

This article describes the recommended dosages for Relenza. The drugmaker provides these dosages.

If your doctor prescribes this medication, you should follow the dosage they prescribe. Your doctor will determine the dosage that best meets your needs. Do not change your dosage of Relenza without your doctor’s recommendation.

Usual recommended dosages of Relenza in adults

Your dosage of Relenza will depend on whether you’re taking it to:

  • treat the flu
  • prevent the flu because someone in your household has the flu
  • prevent the flu due to a community outbreak

The following table shows the recommended dosages of Relenza for adults, depending on the reason you’re taking it.

PurposeRecommended doseFrequency
flu treatment10 mg (two inhalations)twice per day for 5 days
flu prevention if someone in your household has the flu10 mg (two inhalations)once per day for 10 days
flu prevention if there’s an outbreak in your community10 mg (two inhalations)once per day for 28 days

Dosages of Relenza in children

Relenza is approved to treat the flu in children 7 years and older and to prevent the flu in children 5 years and older. The recommended dosages are the same as those for adults.

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Missed dose of Relenza

Talk with your doctor or pharmacist right away if you realize you forgot to take a dose of Relenza. They may advise you to take the missed dose. Or they may advise you to skip it and take your next dose as scheduled.

Usually, you should take your missed dose of Relenza as soon as you remember. If it’s close to when you’d take your next scheduled dose, skip the missed dose. Do not take two doses at the same time to make up for the missed dose.

For tips on how to plan your doses of Relenza and avoid missing a dose, read this article. You could also try:

  • downloading a reminder app on your phone
  • setting an alarm
  • putting a note where you’ll see it, such as on your calendar, bathroom mirror, or bedside table

Frequently asked questions

Below are answers to some commonly asked questions about Relenza and its dosage.

How does the dosage of Relenza compare with the dosage of Tamiflu?

The dosage for Tamiflu depends on your age, weight, and whether you’re taking it to treat or prevent the flu. Relenza’s dosage depends on whether you’re taking it for flu treatment or prevention. You typically use Relenza and Tamiflu for a similar amount of time.

Talk with your doctor if you have specific questions about how the dosage of Relenza compares with the dosage of Tamiflu, and which one may be the better option for you.

Is Relenza used long term?

No, doctors typically don’t prescribe Relenza as a long-term treatment. Instead, it’s usually recommended for short-term use. Relenza hasn’t been studied for use longer than 28 days.

If you have questions about how long you should use Relenza, talk with your doctor.

How Relenza is used

You’ll inhale Relenza through your mouth once or twice per day.  Each dose of Relenza is 10 mg (two inhalations). Use one blister (powder disk) for each inhalation. Your doctor or pharmacist will show you how to use the inhaler.

If you’re prescribed Relenza twice per day, take each dose 12 hours apart. You can take two doses on the first day as long as it’s been at least 2 hours between doses.

Your doctor may advise that you take this medication around the same time each day. This helps keep a consistent amount of the drug in your body. And that can help the drug work more effectively.

Also, be sure to talk with your doctor or pharmacist if you’re having difficulty using your medication. They can offer recommendations about using it.

You can also refer to the prescribing information, which has instructions on how to use Relenza.

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Overdose of Relenza

It’s important that you do not use more Relenza than your doctor prescribes. Doing so can lead to harmful effects.

What to do if you use too much Relenza

If you think you’ve used too much Relenza, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have severe symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

What to ask your doctor

This article describes the usual recommended dosages for Relenza. If your doctor prescribes this medication, they’ll determine the dosage that’s best for you.

Do not change your dosage of Relenza without your doctor’s recommendation. You should take Relenza exactly as your doctor prescribes it. Let your doctor know if you have concerns or questions about your treatment plan.

Here’s a list of some possible questions you may want to ask your doctor:

  • How do I use the Relenza inhaler?
  • How long should I use Relenza?
  • What should I do if I miss a dosage of Relenza?
  • Is Relenza or Tamiflu a better treatment option for me?

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

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