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Fosdenopterin - Injection

Pronunciation: FOS-den-OP-ter-in

Important: How To Use This Information

This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.


This medication is used to improve survival from a certain genetic disorder (molybdenum cofactor deficiency-MoCD Type A). Fosdenopterin replaces a certain substance that is missing in people with MoCD Type A.

How To Use

Read the Instructions for Use if available from the pharmacist before your child starts using fosdenopterin and each time you get a refill. If you have any questions, ask the doctor or pharmacist.

This medication is given by injection into a vein as directed by your child's doctor, usually once a day.

If you are using this medication at home, learn all preparation and usage instructions from the health care professional. The medication in the vial and the supplies that come with the medication should be used only once. Do not reuse. Take fosdenopterin out of the freezer 30 minutes before use to allow it to reach room temperature. You may also gently roll the vial in between your hands for 3 to 5 minutes. The solution used to mix the medication should also be at room temperature. After adding the solution to the powder, gently swirl the mixture to completely dissolve the powder. Do not shake. Check this product visually for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely.

Use this medication regularly to get the most benefit from it. To help you remember, use it at the same time each day.

Do not increase the dose or use this drug more often or for longer than prescribed. Your child's condition will not improve any faster, and your child's risk of side effects will increase.

Tell the doctor if your child's condition gets worse.

Side Effects

Redness, pain, or swelling at the injection site may occur. If any of these effects last or get worse, tell the doctor or pharmacist promptly.

Remember that this medication has been prescribed because the doctor has judged that the benefit to your child is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell the doctor right away if your child has any serious side effects, including:

  • skin blisters/redness

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

  • rash
  • itching/swelling (especially of the face/tongue/throat)
  • severe dizziness
  • trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

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

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.


Before using fosdenopterin, tell the doctor or pharmacist if your child is allergic to it; or if your child has any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to the pharmacist for more details.

Before using this medication, tell your child's doctor or pharmacist your child's medical history.

This medication may make your child more sensitive to the sun. Limit your child's time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell the doctor right away if your child gets sunburned or has skin blisters/redness. The doctor may direct your child to limit or avoid phototherapy while your child uses this product. Ask the doctor for details.

Before having surgery, tell the doctor or dentist about all the products your child uses (including prescription drugs, nonprescription drugs, and herbal products).

This medication is not usually used by adults. It is unlikely to be used during pregnancy or breast-feeding. Consult your doctor if you have any questions about this medication.

Drug Interactions

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.


If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Alberta residents can call PADIS (Poison and Drug Information Service) 24 hours a day at 1-800-332-1414. Canada residents can call a provincial poison control center.


Do not share this medication with others.

Missed Dose

It is important that your child gets each dose of this medication as scheduled. If your child misses a dose, give it as soon as you remember. If there are less than 6 hours until the next regular dose, skip the missed dose. Do not double the dose to catch up.

If you have questions about missing a dose or you don't have more medication, contact your healthcare provider or pharmacist.


Store the unmixed vial in the original carton in the freezer away from light. The mixing solution may be kept at room temperature. After mixing, use this medication right away or within 4 hours. Do not freeze the mixed solution. Discard any unused portion. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.