Onpattro (patisiran) is a brand-name drug that’s prescribed for nerve damage due to a type of amyloidosis in adults. Onpattro comes as a solution that’s given as an intravenous (IV) infusion by a healthcare professional every 3 weeks. The dosage can vary depending on your weight.

Onpattro is approved by the Food and Drug Administration (FDA) to treat:

  • polyneuropathy (damage to multiple nerves in the body) caused by a condition called hereditary amyloid transthyretin-mediated (hATTR) amyloidosis

Onpattro belongs to a drug class called RNA interference therapy (sometimes called gene silencers). Onpattro is not available in a generic version.

Keep reading for specific information about the dosage of Onpattro, including its strength and how you’ll receive the medication. For a comprehensive look at Onpattro, see this article.

Note: This article describes typical dosages for Onpattro provided by the drug’s manufacturer. However, your doctor will prescribe the Onpattro dosage that’s right for you.

Read below for recommended dosages of Onpattro and other details about the drug.

Onpattro form

Onpattro comes as a solution that’s given as an intravenous (IV) infusion. It’s always given by a healthcare professional.

Onpattro strength

Onpattro comes in one strength of 2 milligrams per milliliter of solution (mg/mL).

Typical dosages

Typically, your doctor will prescribe your Onpattro dosage based on your weight.

The following information describes dosages that are commonly used in adults. Your doctor will determine the best dosage to fit your needs.

Dosage for polyneuropathy caused by hereditary ATTR amyloidosis

Doctors may prescribe Onpattro to treat hereditary ATTR amyloidosis. The drug is typically taken with other drugs.

If your doctor prescribes Onpattro for your hereditary ATTR amyloidosis, your dose will depend on your body weight in kilograms (kg). One kg equals about 2.2 pounds (lb).

If you weigh less than 100 kg, (about 220 lb): Your dosage will be 0.3 mg/kg. Typically, you’ll receive this dosage every 3 weeks.

If you weigh more than 100 kg: Your dosage will likely be 30 mg given every 3 weeks.

On the day of your infusion, you will receive some required medications before your Onpattro infusion begins. These are referred to as premedications and usually include a corticosteroid, two different antihistamines, and acetaminophen. These are given at least 60 minutes before your Onpattro injection to help with side effects during your infusion.

The table below shows the typical dosage schedule. Your doctor will choose a dose that suits your needs.

Body weightOnpattro doseFrequency of dose
less than 100 kg0.3 mg/kgEvery 3 weeks
100 kg or more30 mgEvery 3 weeks

For more information about your specific dosage, talk with your doctor.

Long-term treatment

Onpattro is meant to be used as a long-term treatment. If you and your doctor determine that Onpattro is safe and effective for you, you’ll likely use it long term.

Before you start taking Onpattro, your doctor will discuss your treatment plan with you.

The Onpattro dosage your doctor prescribes will depend on several factors. These include:

  • your body weight
  • how your body responds to Onpattro
  • side effects you may have with Onpattro

Other medical conditions you have can also affect your Onpattro dosage.

Your doctor or another healthcare professional will give you the intravenous (IV) infusion of Onpattro. You’ll likely go to your doctor’s office, an infusion center, or a hospital to receive your infusion. The Onpattro infusion takes about an hour and a half. However, you will be given your premedications at least 60 minutes before your Onpattro infusion starts, so you’ll likely be at the infusion center for at least 3 hours.

If you have questions about how to use Onpattro, talk with your doctor or pharmacist. There’s also a helpful page on what to expect at your infusion on the manufacturer’s website.

If you miss your appointment for an Onpattro infusion, call your doctor’s office as soon as possible to reschedule. They’ll adjust your dosing schedule as needed.

If you need help remembering your appointments, try setting an alarm or downloading a reminder app on your phone.

Below are some frequently asked questions about Onpattro.

Is the dosage of Onpattro similar to the dosage of Amvuttra or Tegsedi?

No, the way Onpattro is given is different than Amvuttra (vutrisiran) and Tegsedi (inotersen). While all three drugs are liquids, Onpattro is given as an intravenous (IV) infusion every 3 weeks. Amvuttra is given as a subcutaneous (under the skin) injection administered by a healthcare professional every 3 months. Tegsedi can be self-administered at home as a subcutaneous injection every week.

The dose in milligrams for each drug also differs because they have different active ingredients. Your doctor will prescribe the drug and the dosage that’s right for you.

To learn more about how these drugs compare, talk with your doctor.

How long does it take for Onpattro to start working?

Onpattro starts to work after your first dose. Because of how the drug works, you likely won’t feel the drug working in your body. But your doctor will monitor you during treatment to check whether the drug is working to treat your condition.

Over time, you may notice your symptoms improving. Even if you don’t notice any improvement, Onpattro can still help slow down the progression (worsening) of damage to your nerves from your hereditary ATTR amyloidosis.

Talk with your doctor if you have questions about what to expect with Onpattro treatment.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Onpattro for you, they will prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes.

As with any drug, never change your dosage of Onpattro without your doctor’s recommendation. If you have questions about the dosage of Onpattro that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Onpattro. These additional articles might be helpful:

  • More about Onpattro: For information about other aspects of Onpattro, refer to this article.
  • Side effects: To learn about side effects of Onpattro, see the Onpattro prescribing information.

Disclaimer: Medical News Today 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.