Spinraza (nusinersen) is a prescription drug used to treat spinal muscular atrophy. The drug comes as a liquid solution injected into the spinal cord fluid. It’s usually given once every 4 months after the first four doses.

Spinraza is used in adults and children to treat spinal muscular atrophy.

The active ingredient in Spinraza is nusinersen. (An active ingredient is what makes a drug work.) Spinraza belongs to a group of drugs called antisense oligonucleotides.

This article describes the dosage of Spinraza, as well as its strength and how it’s given. To learn more about Spinraza, see this in-depth article.

The table below highlights the basics of Spinraza’s dosage for spinal muscular atrophy (SMA). All doses are listed in milligrams (mg) and milliliters (mL).

ConditionStarting dosageOngoing dosage
SMA12 mg (5 mL) once every 2 weeks for three doses, followed by a fourth dose 30 days later12 mg (5 mL) once every 4 months, starting 4 months after the fourth dose

Keep reading for more details about Spinraza’s dosage.

What is Spinraza’s form?

Spinraza comes as a preservative-free liquid solution. It’s given as an intrathecal injection (an injection into the fluid around your spinal cord) by a healthcare professional.

What strength does Spinraza come in?

Spinraza comes in one strength of 12 mg of medication per 5 mL of liquid solution (2.4 mg/mL).

What’s the usual dosage of Spinraza in adults?

The information below describes the dosage that’s commonly used or recommended. But your doctor will determine the best dosage to fit your needs.

Dosage for SMA

The typical dose of Spinraza for adults with SMA is one injection of 12 mg (5 mL). For the first three doses, you’ll receive one injection of Spinraza every 2 weeks. You’ll receive a fourth injection of Spinraza 30 days later. After that, you’ll typically receive one injection of Spinraza every 4 months.

What’s the dosage of Spinraza for children?

Spinraza is used to help treat SMA in children of any age, including newborns. The dosage for children is the same as the dosage for adults. To learn more, see the “What’s the usual dosage of Spinraza in adults?” section above.

Is Spinraza used long term?

Yes, Spinraza is usually used as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely use it long term.

Spinraza comes as a liquid solution. It’s given as an intrathecal injection (an injection into the fluid around your spinal cord). For this type of injection, a healthcare professional uses a procedure called a lumbar puncture (commonly known as a spinal tap).

You’ll receive Spinraza injections at a treatment center that has been approved to administer the drug.

For more information on how Spinraza is given, see these details from the drug’s manufacturer. You can also talk with your doctor.

If you miss an appointment to receive a dose of Spinraza, call your doctor’s office as soon as possible to reschedule. If you need help remembering your appointments, try downloading a reminder app on your phone.

Below are answers to some commonly asked questions about Spinraza’s dosage.

How long does it take for Spinraza to start working?

Spinraza starts to work after your first dose. However, it may take several months for the drug to ease the symptoms of your condition. Your doctor will monitor you during treatment to check whether the drug is working to treat your condition.

If you have other questions about what to expect from your Spinraza treatment, talk with your doctor.

Can Spinraza be used for muscular dystrophy? If so, what’s the dosage?

No, Spinraza is not prescribed for muscular dystrophy. It’s only approved to treat spinal muscular atrophy (SMA). To learn about how muscular dystrophy compares with SMA, see this article.

Because Spinraza isn’t used for muscular dystrophy, the drug manufacturer doesn’t provide recommended dosages for this use.

However, other drugs are approved for muscular dystrophy. Examples include:

To learn more about your treatment options for either condition, talk with your doctor.

The sections above describe the usual dosage provided by the manufacturer. If your doctor recommends Spinraza for you, 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:

  • Will my dosage change if Spinraza isn’t working for my condition?
  • Will I need to continue receiving Spinraza even if my condition has improved?
  • Can I drive myself to and from my appointment to receive Spinraza?

To learn more about Spinraza, see these articles:

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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.