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Calcium oxybate/magnesium oxybate/potassium oxybate/sodium oxybate (By mouth)

Calcium Oxybate (KAL-see-um OX-i-bate), Magnesium Oxybate (mag-NEE-zee-um OX-i-bate), Potassium Oxybate (poe-TAS-ee-um OX-i-bate), Sodium Oxybate (SOE-dee-um OX-i-bate)

Treats sudden onset of weak or paralyzed muscles, or excessive daytime sleepiness in patients with narcolepsy. Also treats idiopathic hypersomnia.

Brand Name(s):

Xywav

When This Medicine Should Not Be Used:

How to Use This Medicine:

Liquid

• Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
• This medicine can be taken as a single dose (for idiopathic hypersomnia) or divided into 2 nightly doses. The first nightly dose should be taken at least 2 hours after you eat.
• This medicine can make you sleep very quickly (within 5 to 15 minutes) without feeling drowsy. Take it only at bedtime when you are ready to fall asleep. Stay in bed after you take the first dose.
• Measure your dose with the marked plastic syringe that comes with the medicine. Mix it with 1/4 cup of water. Mix both doses before you go to bed. Store the second dose close to your bed, out of the reach of children.
• Take the second dose 2 1/2 to 4 hours after you take the first dose. You may need to set an alarm clock to wake you up so you can take the second dose on time. Remain on your bed after taking the first and second doses of this medicine.
• Use the medicine within 24 hours after it has been mixed with water.
• This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.
• Missed dose: If you miss the second dose, skip that dose and do not take any more medicine until the next night. Do not use extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Pour any unused medicine down the sink drain after 24 hours. Use a marker to cross out the label on the bottle, then throw it in the trash.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Do not drink alcohol while you are using this medicine. Do not use this medicine if you are also using a sedative medicine.
• Some medicines can affect how calcium oxybate/magnesium oxybate/potassium oxybate/sodium oxybate works. Tell your doctor if you are using any of the following:
  • Divalproex sodium
  • Any other medicine that makes you sleepy, including sleeping pills, cold and allergy medicine, or narcotic pain medicine

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, lung or breathing problems (including hypopnea, sleep apnea), obesity, or a history of depression or alcohol or drug abuse.
• This medicine may cause the following problems:
  • Serious breathing problems, which can be life-threatening
  • Changes in mood or behavior
  • Sleeping problems, including sleepwalking, which can cause injuries
• This medicine may make you dizzy, drowsy, or less alert. Do not drive or do anything else that could be dangerous for at least 6 hours after you take this medicine.
• This medicine can be habit-forming. Do not use more than your prescribed dose. Call your doctor if you think your medicine is not working.
• Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Depression, anxiety, confusion, unusual mood or behavior, seeing or hearing things that are not there, thoughts of hurting yourself
• Extreme dizziness or weakness, slow heartbeat or breathing, seizures, trouble breathing, cold, clammy skin
• Sleepwalking, abnormal dreams

If you notice these less serious side effects, talk with your doctor:

• Bedwetting
• Decreased appetite, dry mouth
• Diarrhea, nausea, vomiting
• Headache, dizziness
• Increased sweating

If you notice other side effects that you think are caused by this medicine, tell your doctor

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

Last Updated: 9/6/2024