Spinraza (nusinersen) is a brand-name drug that’s prescribed for spinal muscular atrophy (SMA) in adults and children. Spinraza comes as a spinal injection that’s given by a healthcare professional every 4 months.

Spinraza belongs to a drug class called antisense oligonucleotide. Spinraza is not available in a generic version.

Keep reading for specific information about the dosage of Spinraza, including its strength and how to use the medication. For a comprehensive look at Spinraza, see this article.

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

Below is information about Spinraza’s recommended dosage.

Spinraza form

Spinraza comes as a solution that’s given as an intrathecal injection. This is an injection into the fluid in your spinal cord. It’s always given by a healthcare professional.

Spinraza strength

Spinraza comes in one strength of 2.4 milligrams per 1 milliliter of solution (mg/mL). Each vial of Spinraza contains 12 mg/5 mL.

Typical dosages

Typically, your doctor will start by prescribing you an initial dosage regimen. Then, they’ll schedule you on a regular maintenance dose long term.

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

Dosage for spinal muscular atrophy

Doctors may prescribe Spinraza to treat SMA.

If your doctor prescribes Spinraza for SMA, they will put you on an initial loading-dose regimen. A loading-dose regimen is when drug doses are given faster at the beginning of your treatment. This helps the drug start working more quickly.

Typically, Spinraza treatment begins with four loading doses of 12 mg each. The first three are given every 2 weeks. The fourth loading dose is given 30 days after the third.

The table below shows the typical loading dose schedule:

Day of treatmentSpinraza dose
Day 112 mg
Day 1512 mg
Day 2912 mg
Day 5912 mg

Spinraza maintenance doses of 12 mg are given every 4 months after the fourth loading dose.

This is the typical recommended dosage for people with SMA and the maximum dosage of Spinraza that’s recommended.

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

Children’s dosage

Spinraza is approved to treat SMA in children of all ages. The dosage for Spinraza in children is the same as the dosage in adults. For dosage details, see the “Dosage for spinal muscular atrophy section” above.

Long-term treatment

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

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

Your doctor or another healthcare professional will give you the Spinraza injection into the fluid of your spine.

They will allow the Spinraza liquid to warm to room temperature. Then, they will draw the liquid into a syringe and inject Spinraza into the fluid of your spine over 1–3 minutes. You’ll likely go to your doctor’s office, an infusion center, or a hospital to receive your injection.

If you miss your appointment for a Spinraza injection, call your doctor’s office as soon as possible to reschedule. They’ll adjust your dosing schedule as needed. If you go too long without rescheduling a missed dose, your doctor may have to restart parts or all of the loading-dose regimen.

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 Spinraza.

How long does it take for Spinraza to start working?

Spinraza 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.

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

Is there a typical dosage range for Spinraza?

No, the typical recommended dosage for Spinraza is 12 milligrams (mg) per dose. There are no recommended dosage ranges for Spinraza.

Spinraza has a recommended loading-dose regimen and maintenance-dose regimen. The recommended dose of Spinraza is 12 mg for each dose. The difference between the loading-dose regimen and the maintenance-dose regimen is the amount of time between doses.

For more information about Spinraza dosages, see the “Spinraza dosage” section above. You can also talk with your doctor or pharmacist.

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

If you have questions about the dosage of Spinraza that’s best for you, talk with your doctor.

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

  • More about Spinraza: For information about other aspects of Spinraza, refer to this article.
  • Side effects: To learn about side effects of Spinraza, see the Spinraza prescribing information.
  • Cost: If you’d like to learn about Spinraza and cost, see this article.

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.