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Viltolarsen (Intravenous)

Commonly used brand name(s)

In the U.S.

  • Viltepso

Available Dosage Forms:

  • Solution

Therapeutic Class: Musculoskeletal Agent

Uses for viltolarsen

Viltolarsen injection is used to treat Duchenne muscular dystrophy (DMD) in patients with a confirmed specific genetic mutation. DMD is a rare, inherited muscle disease that is caused by absence of a protein called dystrophin, which helps keep muscle cells intact.

Viltolarsen is to be given only by or under the direct supervision of a doctor.

Before using viltolarsen

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For viltolarsen, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to viltolarsen or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of viltolarsen injection in children.


No information is available on the relationship of age to the effects of viltolarsen injection in geriatric patients. DMD is usually a disease of children and young adults.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with food/tobacco/alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of viltolarsen. Make sure you tell your doctor if you have any other medical problems, especially:

  • Kidney disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.

Proper use of viltolarsen

A nurse or other trained health professional will give you or your child viltolarsen in a medical facility. Viltolarsen is given through a needle placed in one of your veins. It must be given slowly, so the needle should remain in place for at least 60 minutes once a week.

Missed dose

Viltolarsen needs to be given on a fixed schedule. If you miss a dose or forget to use your medicine, call your doctor or pharmacist for instructions.

Precautions while using viltolarsen

Your doctor will check your or your child's progress closely while you are receiving viltolarsen to see if it is working properly and to decide if you or your child should continue to receive it. Blood and urine tests may be needed to check for unwanted effects.

Check with your doctor right away if you or your child has blood in the urine, change in frequency of urination or amount of urine, drowsiness, increased thirst, loss of appetite, nausea or vomiting, swelling of the feet or lower legs, trouble breathing, or weakness. These could be symptoms of a serious kidney problem.

Viltolarsen side effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

  • Body aches or pain
  • chills
  • cough
  • confusion
  • diarrhea
  • difficulty in moving
  • ear congestion
  • fast, pounding, or irregular heartbeat
  • fever
  • headache
  • joint pain
  • loss of voice
  • muscle pain or stiffness
  • nausea
  • runny or stuffy nose
  • sneezing
  • sore throat
  • stomach pain
  • swelling of the face, ankles, or hands
  • trouble breathing
  • unusual bruising
  • unusual tiredness or weakness
  • vomiting

Incidence not known

  • Agitation
  • blood in the urine
  • coma
  • decreased urine output
  • depression
  • dizziness
  • irritability
  • lethargy
  • muscle twitching
  • rapid weight gain
  • seizures
  • stupor

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • hives or welts, itching, skin rash
  • redness of the skin

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.