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Overview: Kygevvi is used to treat certain people with a condition called thymidine kinase 2 deficiency (TK2d). Both diarrhea and vomiting are common side effects. If you have either diarrhea or vomiting that lasts for more than a few days or is severe, call your health care provider right away. Carefully follow directions on how to prepare and give this medicine.

Uses

What is Kygevvi used for?

Kygevvi (doxecitine/doxribtimine) is commonly used to treat certain people with thymidine kinase 2 deficiency (TK2d).

Kygevvi may also be used for other conditions as determined by your health care provider.

How does Kygevvi work (mechanism of action)?

People with thymidine kinase 2 deficiency (TK2d) have a problem in a gene from both parents. The gene gives your body the directions to make a protein (enzyme) that you need to make and repair DNA inside mitochondria. Mitochondria are found inside your cells and are the energy factories. 

If you have TK2d, you cannot fix DNA inside your mitochondria. As a result, you can lose what is called mitochondrial DNA. Over time, your muscles can become  weaker. Muscle weakness may make it hard to swallow, stand, or breathe.

Kygevvi provides two building blocks of DNA: deoxycytidine and deoxythymidine. These parts are thought to get into the mitochondrial DNA of a type of muscle called skeletal muscle. As a result, the amount of mitochondrial DNA is thought to increase. Kygevvi can reduce your risk of death.

How is Kygevvi supplied (dosage forms)?

Brands and other names

  • Kygevvi

Dosage forms and strengths

  • 2 g/2 g single-dose packets of powder for oral solution

How should I store Kygevvi?

Kygevvi unopened packets should be stored at room temperature, between 68 F and 77 F (20 C and 25 C). They can be exposed to temperatures between 59 F and 86 F (15 C and 30 C) for shorter periods of time, such as when transporting them. Store in a cool, dry place. 

Mixed Kygevvi should be stored at room temperature, between 68 F and 77 F (20 C and 25 C) or in a refrigerator between 36 F and 46 F (2 C and 8 C). Do not freeze. Make sure that the dosing cap is screwed on tightly to the mixing bottle, and store the bottle upright. Use the solution within 16 hours of mixing it. Throw any remaining solution away once the three doses have been taken or given or if more than 16 hours have passed.

Side Effects

What are the most common side effects of Kygevvi?

The most common side effects of Kygevvi are listed below. Tell your health care provider if you have any of these side effects that bother you.

There may be other side effects of Kygevvi that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of Kygevvi?

While less common, the most serious side effects of Kygevvi are described below, along with what to do if they happen.

Severe Allergic Reactions. Kygevvimay cause allergic reactions, which can be serious. Stop taking Kygevvi and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching or skin rash
  • Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking Kygevvi. Liver damage may be picked up by blood tests. Keep all appointments to have your blood checked. Call your health care provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Diarrhea or Vomiting. Diarrhea and vomiting are common with Kygevvi but can be severe and require that you be hospitalized. Call your health care provider right away if you have diarrhea or vomiting that does not go away after a few days, goes away and comes back, or is severe.

Warnings & Precautions

Who should not use Kygevvi?

Allergies to Ingredients. People who are allergic to any of the following should not take Kygevvi.

  • Doxecitine
  • Doxribtimine
  • Kygevvi 
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in Kygevvi.

What should I know about Kygevvi before using it?

Do not take Kygevvi unless it has been prescribed to you by a health care provider. Take it as prescribed. If you do not know how much to take or when to take it, talk with your health care provider. Kygevvi is usually given three times a day, about 6 hours apart. Take each dose with food. 

Do not share Kygevvi with other people, even if they have the same condition as you. It may harm them.

Keep Kygevvi out of the reach of children. An adult needs to prepare and give the Kygevvi solution to a child. Since this liquid form of this medicine may be kept in a refrigerator, take special precautions to keep it away from children who also use the refrigerator.

Your health care provider may change your dose of this medicine based on how you respond. Your dose may also change if you are a growing child who gains weight.

Only mix the powder from the packet with room temperature water. Do not use hot or very cold water. Do not mix the powder with any other liquid or food. 

You will only prepare enough medicine for 1 day at a time. Each morning, prepare the solution for the day. Use the ZX2000 administration kit that you get from your pharmacy to prepare the Kygevvi solution. Only use the provided dosing cup, mixing bottle, and oral syringes to measure your dose. A household spoon or measuring cup is not an accurate measuring device and may cause you to take the wrong dose. 

Read the “Instructions for Use” that comes with your medicine. The document has information about how to safely prepare, use, and give this medicine.

What should I tell my health care provider before using Kygevvi?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if Kygevvi is right for you.

In particular, make sure that you discuss any of the following.

Liver Problems. Tell your health care provider if you have ever had a liver problem. You may have had high liver enzymes or bilirubin that was found by bloodwork. 

Pregnancy. It is not known if or how Kygevvi could affect pregnancy or harm an unborn baby. Tell your health care provider if you are pregnant or plan to become pregnant. Your health care provider will let you know if you should take Kygevvi while you are pregnant or trying to get pregnant.

Breastfeeding. It is not known if Kygevvi passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should take Kygevvi while breastfeeding.

How can I get more information about Kygevvi?

For more information about Kygevvi, you can visit the drugmaker’s website at www.kygevvi.com or call them at 844-599-2273.

Interactions

Does Kygevvi interact with foods or drinks?

There are no known interactions between Kygevvi and foods or drinks. Take each dose of Kygevvi with food. Food helps the medicine get absorbed by your body.

It is unknown if drinking alcohol will affect Kygevvi, but both alcohol and Kygevvi may damage your liver. It is best to limit the amount of alcohol you drink.

Does Kygevvi interact with other medicines (drug interactions)?

There are no known interactions between Kygevvi and other medicines. Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much Kygevvi?

If you or someone else has used too much Kygevvi, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of Kygevvi?

If you miss a dose, take it as soon as you remember. If it is within 2 hours of your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses. 

If you spit out the dose or do not take your full dose for any reason, do not take another dose. Take the next dose at your next scheduled time.