Xywav is an oral solution that contains oxybate, specifically a combination of calcium, magnesium, potassium, and sodium oxybate, with a total concentration equivalent to 0.5 g/mL and 0.413 g/mL of oxybate. It acts as a central nervous system (CNS) depressant. The formulation is a liquid solution with inactive ingredients including purified water and sucralose.

How should I use this medication?

Take this medication by mouth. Follow the directions on the prescription label. Use a specially marked oral syringe, spoon, or dropper to measure each dose. Ask your pharmacist if you do not have one. Household spoons are not accurate. Mix the dose with water as directed. Take this medication on an empty stomach, or at least 2 hours after food. Take your medication at regular intervals. Do not take it more often than directed. Do not stop taking except on your care team's advice. This medication comes with INSTRUCTIONS FOR USE. Ask your pharmacist for directions on how to use this medication. Read the information carefully. Talk to your pharmacist or care team if you have questions. A special MedGuide will be given to you by the pharmacist with each prescription and refill. Be sure to read this information carefully each time. Talk to your care team about the use of this medication in children. While this medication may be prescribed for children as young as 7 years for selected conditions, precautions do apply.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once. NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, skip it. Take your next dose at the normal time. Do not take extra or 2 doses at the same time to make up for the missed dose.

Where should I keep my medication?

Keep out of the reach of children and pets. This medication can be abused. Keep it in a safe place to protect it from theft. Do not share it with anyone. It is only for you. Selling or giving away this medication is dangerous and against the law. Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Keep this medication in the original container. Get rid of any unused medication after the expiration date. After mixing a dose of this medication with water, the medication should be taken within 24 hours. Get rid of any unused and diluted medication. This medication may cause harm and death if it is taken by other adults, children, or pets. It is important to get rid of the medication as soon as you no longer need it or it is expired. You can do this in two ways: -Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location. -If you cannot return the medication, flush it down the toilet.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible: -Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat -CNS depression—slow or shallow breathing, shortness of breath, feeling faint, dizziness, confusion, trouble staying awake -Mood and behavior changes—anxiety, nervousness, confusion, hallucinations, irritability, hostility, thoughts of suicide or self-harm, worsening mood, feelings of depression -Sleep apnea—loud snoring, gasping or choking during sleep, daytime sleepiness -Sleepwalking Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome): -Bedwetting -Dizziness -Headache -Loss of appetite -Nausea -Vomiting

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions: -Depression -Frequently drink alcohol -History of substance use disorder -Liver disease -Lung or breathing disease, such as asthma or COPD -Mental health conditions -Sleep apnea -Succinic semialdehyde dehydrogenase deficiency -Suicidal thoughts, plans, or attempt by you or a family member -An unusual or allergic reaction to oxybate, other medications, foods, dyes, or preservatives -Pregnant or trying to get pregnant -Breastfeeding

What may interact with this medication?

Do not take this medication with any of the following: -Alcohol -Medications that help you fall asleep This medication may also interact with the following: -Benzodiazepines, such as alprazolam, diazepam, lorazepam -Certain antihistamines for allergy, cough, and cold -Certain medications for depression, such as amitriptyline, fluoxetine, sertraline -Certain medications for seizures, such as phenobarbital or primidone -Divalproex sodium -Medications that cause drowsiness before a procedure, such as halothane, isoflurane, methoxyflurane, propofol -Medications that relax muscles for surgery -Opioids for pain or cough -Phenothiazines, such as chlorpromazine, mesoridazine, prochlorperazine, thioridazine -Valproate or valproic acid

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Tell your care team if your symptoms do not start to get better or if they get worse. This medication has a risk of abuse and dependence. Your care team will check you for this while you take this medication. This medication causes sleep very quickly. You should only take your first dose at bedtime, while in bed. If you take this medication twice nightly, take the second dose 2.5 to 4 hours after your first dose. This medication may affect your coordination, reaction time, or judgment. Do not drive or operate machinery until you know how this medication affects you. Sit up or stand slowly to reduce the risk of dizzy or fainting spells. Drinking alcohol with this medication can increase the risk of these side effects. You may do unusual sleep behaviors or activities you do not remember the day after taking this medication. Activities include driving, making or eating food, talking on the phone, sexual activity, or sleep walking. Serious injuries have occurred. Call your care team right away if you find out you have done any of these activities. Do not take this medication if you have used alcohol that evening. Do not take it if you have taken another medication for sleep. The risk of doing these sleep-related activities is higher. This medication may cause thoughts of suicide or depression. This includes sudden changes in mood, behaviors, or thoughts. These changes can happen at any time but are more common in the beginning of treatment or after a change in dose. Call your care team right away if you experience these thoughts or worsening depression.

What are the most serious risks of this medication?

Misuse of this medicine can cause addiction or overdose. Take it exactly as prescribed. Store it in a safe place to prevent stealing or abuse. It is illegal to sell it or give it away. This drug is a CNS depressant. It can cause deadly breathing problems. It can also cause drowsiness. Do not drive a car, use heavy machinery, or do other activities where you need to be fully awake for at least 6 hours after you take a dose. This risk is greatest when you first start taking it. The risk is also high if you take other drugs that cause drowsiness like narcotic pain drugs, narcotic cough drugs, benzodiazepines, other drugs for sleep, and muscle relaxants. Do not drink alcohol. Tell your health care provider about all the drugs you take, including over-the-counter drugs and vitamins. Get emergency help right away if you have trouble breathing or are unusually tired or sleepy.