WHAT ARE THE POSSIBLE SIDE EFFECTS OF KOSELUGO?

As with any medicine, it’s possible to experience side effects. Be sure to tell your child’s doctor if your child experiences any side effect that bothers them or does not go away.

Koselugo may cause serious side effects, including:

Heart problems: Koselugo can lower the amount of blood pumped by your heart, which is common and can also be severe. Your child’s healthcare provider will do tests before and during treatment with Koselugo to check how well your child’s heart is working. Tell your child’s healthcare provider right away if your child gets any of the following signs or symptoms:

  • persistent coughing or wheezing
  • tiredness
  • shortness of breath
  • increased heart rate
  • swelling of your child’s ankles and feet

Eye problems: Koselugo can cause eye problems that can lead to blindness. Your child’s healthcare provider will check your child’s vision before and during treatment with Koselugo. Tell your child’s healthcare provider right away if your child gets any of the following signs or symptoms:

  • loss of vision
  • dark spots in your child’s vision (floaters)
  • other changes to your child’s vision

Severe diarrhea: Diarrhea is common with Koselugo and can also be severe. Tell your child’s healthcare provider right away the first time that your child gets diarrhea during treatment with Koselugo. Your child’s healthcare provider may give your child medicine to help control diarrhea and may tell them to drink more fluids

Skin rash: Skin rashes are common with Koselugo and can also be severe. Tell your child’s healthcare provider if your child gets any of the following signs or symptoms:

  • rash that covers a large area of your child’s body
  • blisters
  • peeling skin

Muscle problems (rhabdomyolysis): Muscle problems are common with Koselugo and can also be severe. Treatment with Koselugo may increase the level of a muscle enzyme in your child’s blood, which may be a sign of muscle damage. Your child’s healthcare provider should do a blood test to check your child’s muscle enzyme levels before they start taking Koselugo and during treatment. Tell your child’s healthcare provider right away if your child gets any of the following signs or symptoms:

  • muscle aches or pain
  • dark, reddish urine
  • muscle spasms and weakness

Your child’s healthcare provider may change your child’s dose, temporarily stop, or permanently ask your child to stop taking Koselugo if they have any of these side effects.


The most common side effects of Koselugo are:


 Vomiting
 Stomach pain
 Nausea
 Dry skin
 Feeling of tiredness, weakness, or lacking energy
 Muscle and bone pain
 Fever
 Inflammation of the mouth
 Headache
 Redness around the fingernails
Itching

These are not all the possible side effects of Koselugo

For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Remember, the information on this page does not replace medical guidance or directions from your doctor. Always talk to them about side effects and ways to manage them.

See what people taking Koselugo experienced in a clinical study.

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ARE THERE ANY TESTS NEEDEDBEFORE STARTING KOSELUGO?

Make a list of questions you’d like to ask your child’s doctor and information you’d like to share about your child:

1

Ask what tests are needed before and during treatment

2

Share details about pre-existing conditions

3

Provide names of other medicines your child may be taking

Your child will take 3 tests before starting Koselugo:

  • A test using sound waves to painlessly create pictures of the heart (called an echocardiogram)
  • A blood test for certain enzymes and naturally occurring chemicals
  • An assessment of your child’s eyes

Before starting Koselugo, tell your child’s doctor about all of your child’s medical conditions, including if they:

Have heart problems

Have eye problems

Are pregnant or plan to become pregnant. Koselugo can harm an unborn baby

  • Your child’s healthcare provider should check to see if your child is pregnant before they begin treatment with Koselugo
  • Females who are able to become pregnant should use effective birth control (contraception) during treatment with Koselugo and for 1 week after the last dose
  • Males with female partners who are able to become pregnant should use effective birth control (contraception) during treatment with Koselugo and for 1 week after the last dose
  • Tell your child’s healthcare provider right away if your child becomes pregnant or thinks she may be pregnant during treatment with Koselugo

Are breastfeeding or plan to breastfeed

  • It is not known if Koselugo passes into breast milk
  • Your child should not breastfeed during treatment with Koselugo and for 1 week after the last dose
  • Talk to your child’s healthcare provider about the best way for your child to feed her baby during this time

Tell your child’s healthcare provider about all the medicines your child takes, including prescription and over-the-counter medicines, vitamins, or herbal supplements. Especially tell your child’s healthcare provider if your child is taking aspirin, blood thinners, or other medicines to treat blood clots. Koselugo contains vitamin E, which may increase the risk of bleeding.

Review the treatment journey of patients who took Koselugo in a clinical study

See their journeys here

IMPORTANT SAFETY INFORMATION

Before taking Koselugo, tell your healthcare provider about all of your medical conditions, including if you:

  • have heart problems
  • have eye problems
  • have liver problems
  • are pregnant or plan to become pregnant. Koselugo can harm your unborn baby
    • Females who could become pregnant and males with female partners who could become pregnant should use effective birth control (contraception) during treatment with Koselugo and for 1 week after your last dose
    • Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with Koselugo
  • Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with Koselugo
    • Do not breastfeed during treatment with Koselugo and for 1 week after your last dose
    • Talk to your healthcare provider about the best way to feed your baby during this time

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, or herbal supplements. Especially tell your healthcare provider if you are taking aspirin, blood thinners, or other medicines to treat blood clots. Koselugo contains vitamin E, which may increase your risk of bleeding.

Koselugo may cause serious side effects, including:
Heart problems.
Koselugo can lower the amount of blood pumped by your heart, which is common and can also be severe. Your healthcare provider will do tests before and during treatment with Koselugo to check how well your heart is working. Tell your healthcare provider right away if you get any of the following signs or symptoms:

  • persistent coughing or wheezing
  • shortness of breath
  • swelling of your ankles and feet
  • tiredness
  • increased heart rate

Eye problems. Koselugo can cause eye problems that can lead to blindness. Your healthcare provider will check your vision before and during treatment with Koselugo. Tell your healthcare provider right away if you get any of the following signs or symptoms:

  • blurred vision
  • loss of vision
  • dark spots in your vision (floaters)
  • other changes to your vision

Severe diarrhea. Diarrhea is common with Koselugo and can also be severe. Tell your healthcare provider right away the first time that you get diarrhea during treatment with Koselugo. Your healthcare provider may give you medicine to help control your diarrhea and may tell you to drink more fluids.

Skin rash. Skin rashes are common with Koselugo and can also be severe. Tell your healthcare provider if you get any of the following signs or symptoms:

  • rash that covers a large area of your body
  • peeling skin
  • blisters

Muscle problems (rhabdomyolysis). Muscle problems are common with Koselugo and can also be severe. Treatment with Koselugo may increase the level of a muscle enzyme in your blood, which may be a sign of muscle damage. Your healthcare provider should do a blood test to check your muscle enzyme levels before you start taking Koselugo and during treatment. Tell your healthcare provider right away if you get any of the following signs or symptoms:

  • muscle aches or pain
  • muscle spasms and weakness
  • dark, reddish urine

Your healthcare provider may change your dose, temporarily stop, or permanently ask you to stop taking Koselugo if you have any of these side effects.

The most common side effects of Koselugo are:

  • vomiting
  • stomach-area pain
  • nausea
  • dry skin
  • muscle and bone pain
  • feeling of tiredness or lacking energy
  • fever
  • sores in your mouth
  • headache
  • redness around the fingernails
  • itching

These are not all the possible side effects of Koselugo.

  • are pregnant or plan to become pregnant. Koselugo can harm your unborn baby
    • Females who could become pregnant and males with female partners who could become pregnant should use effective birth control (contraception) during treatment with Koselugo and for 1 week after your last dose
    • Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with Koselugo
  • Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with Koselugo
    • Do not breastfeed during treatment with Koselugo and for 1 week after your last dose
    • Talk to your healthcare provider about the best way to feed your baby during this time

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, or herbal supplements. Especially tell your healthcare provider if you are taking aspirin, blood thinners, or other medicines to treat blood clots. Koselugo contains vitamin E, which may increase your risk of bleeding.

Koselugo may cause serious side effects, including:
Heart problems.
Koselugo can lower the amount of blood pumped by your heart, which is common and can also be severe. Your healthcare provider will do tests before and during treatment with Koselugo to check how well your heart is working. Tell your healthcare provider right away if you get any of the following signs or symptoms:

  • persistent coughing or wheezing
  • shortness of breath
  • swelling of your ankles and feet
  • tiredness
  • increased heart rate

Eye problems. Koselugo can cause eye problems that can lead to blindness. Your healthcare provider will check your vision before and during treatment with Koselugo. Tell your healthcare provider right away if you get any of the following signs or symptoms:

  • blurred vision
  • loss of vision
  • dark spots in your vision (floaters)
  • other changes to your vision

Severe diarrhea. Diarrhea is common with Koselugo and can also be severe. Tell your healthcare provider right away the first time that you get diarrhea during treatment with Koselugo. Your healthcare provider may give you medicine to help control your diarrhea and may tell you to drink more fluids.

Skin rash. Skin rashes are common with Koselugo and can also be severe. Tell your healthcare provider if you get any of the following signs or symptoms:

  • rash that covers a large area of your body
  • peeling skin
  • blisters

Muscle problems (rhabdomyolysis). Muscle problems are common with Koselugo and can also be severe. Treatment with Koselugo may increase the level of a muscle enzyme in your blood, which may be a sign of muscle damage. Your healthcare provider should do a blood test to check your muscle enzyme levels before you start taking Koselugo and during treatment. Tell your healthcare provider right away if you get any of the following signs or symptoms:

  • muscle aches or pain
  • muscle spasms and weakness
  • dark, reddish urine

Your healthcare provider may change your dose, temporarily stop, or permanently ask you to stop taking Koselugo if you have any of these side effects.

The most common side effects of Koselugo are:

  • vomiting
  • stomach-area pain
  • nausea
  • dry skin
  • muscle and bone pain
  • feeling of tiredness or lacking energy
  • fever
  • sores in your mouth
  • headache
  • redness around the fingernails
  • itching

These are not all the possible side effects of Koselugo.