How long do I have to take Onpattro (patisiran)?

Since hATTR is a genetic disorder, it cannot be cured. You'll likely need to take Onpattro (patisiran) for the rest of your life, as long as you're not having side effects and it's helping your condition.

Onpattro

patisiran

Used for Hereditary Transthyretin-Mediated Amyloidosis

Onpattro (patisiran) is a medication used for treating nerve damage (polyneuropathy) due to hereditary transthyretin-mediated amyloidosis (hATTR). It's given as an injection into the veins every 3 weeks by a healthcare provider.

Reviewed by:

Robert Chad Hakim, PharmD, BCCCP

Allison Gourley, PharmD

Last reviewed on June 10, 2022

What is Onpattro (patisiran)?

What is Onpattro (patisiran) used for?

Polyneuropathy from hereditary transthyretin-mediated amyloidosis (hATTR)

How Onpattro (patisiran) works

Your liver makes a protein called transthyretin (TTR). In people with hereditary transthyretin-mediated amyloidosis (hATTR), the gene that makes TTR has a mutation that causes the protein to fold incorrectly into an unusual shape. This unusual shape causes TTR proteins to clump together in clusters called amyloid deposits or fibrils. These amyloid deposits travel throughout your body and can cause damage to your organs and nerves.

Onpattro (patisiran) is a type of molecule called an small interfering ribonucleic acid (siRNA). It's a piece of genetic material that attaches to the TTR gene and breaks it down. This lowers the amount of misshapened TTR proteins in your body, which lowers the amount of amyloid that builds up in your organs.

Drug facts

Common Brands	Onpattro
Drug Class	Small interfering ribonucleic acid (siRNA)
Controlled Substance Classification	Not a controlled medication
Generic Status	No lower-cost generic available
Availability	Prescription only

Common Brands

Onpattro

Drug Class

Small interfering ribonucleic acid (siRNA)

Controlled Substance Classification

Not a controlled medication

Generic Status

No lower-cost generic available

Availability

Prescription only

Side effects of Onpattro (patisiran)

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

Upper respiratory infections (29%)
Infusion-related reactions (19%)
Indigestion (8%)
Shortness of breath (8%)
Muscle spasms (8%)
Joint pain (7%)
Skin redness (7%)
Bronchitis (7%)
Vertigo or a spinning sensation (5%)

Less Common Side Effects

Dry eye
Blurry vision
Eye floaters

Source: DailyMed

The following Onpattro (patisiran) side effects have also been reported

Side effects that you should report to your care team as soon as possible:

Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
Infusion reactions—chest pain, shortness of breath or trouble breathing, feeling faint or lightheaded
Low vitamin A level—change in vision, dry eyes, dry skin, frequent infections

Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):

Pros and cons of Onpattro (patisiran)

Pros

Works well to treat hATTR symptoms
Injected once every 3 weeks

Cons

Needs to be given by a healthcare provider
Brand name only, which can be expensive
Requires you to take several medications 1 hour before the infusion to prevent infusion-related reactions

Pharmacist tips for Onpattro (patisiran)

Mark your appointments to see your provider and receive Onpattro (patisiran) on your calendar. This makes sure your providers can properly monitor you and also helps you remember to receive your doses on time.
The Onpattro (patisiran) infusion takes about an hour and 20 minutes. After your infusion, your provider might want to monitor you for a while just in case you get any reactions to the medication. You can bring a book or something else to do with you to help pass the time.
It's possible to get infusion-related reactions during your Onpattro (patisiran) infusion. Examples of these reactions include flushing, back pain, nausea, stomach pain, shortness of breath, and headache. If you get any of these reactions during your infusion, tell your provider so they can slow or stop the infusion. They can also give you medications to treat your symptoms.
It's best to take a daily vitamin A supplement during Onpattro (patisiran) treatment. This is because the medication can lower the vitamin A levels in your blood. Ask your provider how much vitamin A you should take every day.

Common questions about Onpattro

Yes. Since Onpattro can cause infusion reactions, your provider will give you a few medications at least 1 hour before you receive your infusion to help prevent or lessen the severity of these reactions. This is called premedication and typically includes a steroid, two different antihistamines, and acetaminophen (Tylenol).

Onpattro and Tegsedi (inotersen) both work well to treat symptoms of hATTR. The first major difference is how they're given. Onpattro is given by a healthcare provider as an injection through the vein every 3 weeks, but you can inject Tegsedi under the skin by yourself at home once per week. The second major difference is the potential risks. The manufacturer of Onpattro lists infusion reactions as a warning with medication use. On the other hand, Tegsedi can cause serious bleeding or kidney problems, which is why it's only available through the Risk Evaluation and Mitigation Strategy (REMS) program called the Tegsedi REMS program.

If you miss a dose of Onpattro, contact your provider so you can receive it as soon as possible. If you get your dose within 3 days of your missed scheduled date, you can continue with your current dosing schedule. If you get your dose more than 3 days after your missed scheduled date, your next doses of Onpattro will be scheduled every 3 weeks from the date you received your dose.

There isn't enough information to know if Onpattro is safe to take during pregnancy. In some animal studies, this medication caused harm to pregnant mothers and their babies. If you're pregnant or thinking of becoming pregnant, talk with your provider about the risks and benefits of using this medication during pregnancy. If you're pregnant and are prescribed Onpattro or if you become pregnant while taking this medication, it's recommended you enroll in a pregnancy registry that monitors your and your baby's health outcomes. Contact the registry by calling 1-877-256-9526.

Since hATTR is a genetic disorder, it cannot be cured. You'll likely need to take Onpattro for the rest of your life, as long as you're not having side effects and it's helping your condition.

Risks and warnings for Onpattro (patisiran)

Onpattro (patisiran) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

Infusion reactions

Onpattro (patisiran) can cause infusion-related reactions while you receive the medication. Examples of these reactions include flushing, back pain, nausea, stomach pain, shortness of breath, and headache. If you develop any of these reactions during your infusion, tell your provider so they can slow or stop the Onpattro (patisiran) infusion. They might also give you medications to treat your symptoms. To prevent or lessen the severity of these reactions, your provider will give you a few medications to take at least 1 hour before your Onpattro (patisiran) infusion. These medications include a steroid (e.g., dexamethasone), acetaminophen (Tylenol), a histamine-2 antagonist (e.g., famotidine), and a histamine-1 antagonist (e.g., diphenhydramine (Benadryl)). Your provider might adjust the dose of these medications or switch to different ones, depending on how you respond to them.

Low vitamin A levels

Onpattro (patisiran) can lower your blood vitamin A levels. It's best to take a vitamin A supplement at the recommended daily dose while taking Onpattro (patisiran). If you're pregnant, speak to your provider about what dose of vitamin A is right for you, because having too much or too little vitamin A can affect the development of your baby. Don't take more than the maximum recommended daily dose to try and raise your vitamin A levels, because this can lead to side effects like nausea, dizziness, or headache. Contact your provider if you get night blindness, because this is an early symptom of very low vitamin A.

Onpattro (patisiran) dosage

Typical dosage for Onpattro (patisiran)

Weight of less than 220 lbs (100 kg): The typical dose is 0.3 mg/kg of body weight injected into the veins (intravenously or IV) once every 3 weeks.
Weight of 220 lbs or more: The typical dose is 30 mg IV once every 3 weeks.