Onpattro (patisiran) is a prescription drug. It’s used to treat polyneuropathy caused by hereditary ATTR (hATTR) amyloidosis. Onpattro is given as an intravenous (IV) infusion by a healthcare professional, usually once every 3 weeks.
Onpattro is used in adults to treat polyneuropathy caused by hereditary amyloid transthyretin-mediated amyloidosis. Polyneuropathy is a type of widespread nerve damage.
The active ingredient in Onpattro is patisiran. (An active ingredient is what makes a drug work.) Onpattro belongs to a group of drugs called RNA interference therapy.
This article describes the dosages of Onpattro, as well as its strength and how it’s given. To learn more about Onpattro, see this in-depth article.
The table below highlights the basics of Onpattro’s dosage.
| Weight in kilograms (kg) | Weight in pounds (lb) | Onpattro dosage | Dosing frequency |
|---|---|---|---|
| less than 100 kg | less than 220 lb | 0.3 mg per kg of body weight | once every 3 weeks as an IV infusion |
| 100 kg or more | 220 lb or more | 30 mg | once every 3 weeks as an IV infusion |
Keep reading to learn more about Onpattro’s dosage.
What is Onpattro’s form?
Onpattro is available as a liquid solution that’s given as an IV infusion. This is an injection into your vein over a period of time. Onpattro is given by a healthcare professional in a hospital or clinic.
What strength does Onpattro come in?
Onpattro comes in one strength of 10 mg per 5 milliliters.
What are the usual dosages of Onpattro?
Your doctor will likely start by prescribing the recommended dosage of Onpattro that provides the desired effect. Your dosage is based on your body weight.
The information below describes dosages that are commonly used or recommended. Your doctor will determine the best dosage to fit your needs.
Dosage for polyneuropathy caused by hereditary ATTR amyloidosis
Onpattro is given as an IV infusion over about 80 minutes. You’ll receive doses in a hospital, infusion center, or clinic from a healthcare professional once every 3 weeks.
The typical Onpattro dose to treat polyneuropathy caused by hATTR amyloidosis in adults is based on body weight:
- For people who weigh less than 100 kg, or about 220 lb: The dose is 0.3 mg per kg of body weight.
- For people who weigh 100 kg or more: The dose is 30 mg total.
If you have questions about your dosage of Onpattro, talk with your doctor.
Is Onpattro used long term?
Yes, Onpattro is typically used as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely receive it long term.
The dosage of Onpattro you’re prescribed may depend on:
- your body weight
- side effects you may experience
- how you respond to treatment with Onpattro
Onpattro is given as an IV infusion. It will be slowly injected into your vein over about 80 minutes. You’ll be given Onpattro by a healthcare professional in a clinic or hospital once every 3 weeks. Your dosage will be based on your body weight.
Your doctor will give you certain medications about an hour before you receive Onpattro. These medications will reduce your risk of infusion reactions (side effects that can happen during Onpattro infusion). The medications may include:
- acetaminophen (Tylenol) that you swallow
- corticosteroid, such as dexamethasone (Decadron), given by IV injection
- diphenhydramine (Benadryl) given as an IV injection
- H2 blocker (famotidine) given as an IV injection
Your doctor will also likely recommend that you take a vitamin A supplement while you receive treatment with Onpattro. This is because Onpattro can cause your body’s vitamin A level to become too low. A low level of vitamin A can cause vision problems, such as night blindness (trouble seeing in low light).
You can ask your doctor or pharmacist about the right vitamin A supplement and dosage for you. And if you experience problems with your vision while taking Onpattro, talk with your doctor. They may suggest contacting an eye doctor.
If you miss an appointment to receive Onpattro, call your doctor’s office as soon as possible to reschedule. Your doctor or another health professional will give you the missed dose.
If it’s within 3 days of your scheduled dose, they’ll continue your current dosing schedule of Onpattro. However, if it’s been longer than 3 days since your missed dose, your doctor will give you the missed dose and adjust your dosing schedule.
If you need help remembering your appointments, try downloading a reminder app on your phone.
Below are answers to some commonly asked questions about Onpattro’s dosage.
Is Onpattro’s dosage similar to the dosage of Amvuttra or vutrisiran?
No. Like Onpattro, Amvuttra (whose active ingredient is vutrisiran) is used to treat polyneuropathy caused by hATTR amyloidosis. But Onpattro and Amvuttra have different forms and dosages.
Onpattro is given as an IV infusion by a healthcare professional once every 3 weeks. The dosage is based on body weight.
Amvuttra is given as an injection under the skin by a healthcare professional once every 3 months. Its dosage is not based on body weight.
The dose in milligrams for each drug also differs. 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. But you may not notice any changes in your symptoms for a few months. Your doctor will monitor you closely during your Onpattro treatment to see whether the drug is working to treat your condition.
If you have other questions about what to expect from your Onpattro treatment, talk with your doctor.
The sections above describe the usual dosages provided by Onpattro’s manufacturer. If your doctor recommends this drug, they’ll prescribe the dosage that’s right for you.
Talk with your doctor if you have questions or concerns about your current dosage.
Here are some examples of questions you may want to ask your doctor:
- Will my dosage of Onpattro change if my weight changes?
- Will I have a higher risk for side effects if I receive the 30-mg dose of Onpattro?
- How does the dosage of Onpattro compare with the dosage of Tegsedi (inotersen)?
To learn more about Onpattro, see this article: All About Onpattro.
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Disclaimer: Healthline 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.