Sodium oxybate belongs to a group of medications known as central nervous system (CNS) depressants. It is used to treat narcolepsy by reducing the number of cataplexy (weak or paralyzed muscles) attacks. Narcolepsy is a condition that causes daytime excessive sleepiness. At this time, it is not known exactly how this medication works to reduce cataplexy attacks.

This medication usually starts to work within the first weeks of treatment, but it may take up to 8 weeks for you and your doctor to find the dose that is best for you.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended initial dose of sodium oxybate is 4.5 g per night given in 2 equal doses of 2.25 g. The first dose is taken at bedtime and the second dose is taken 2.5 to 4 hours later. Your doctor may adjust the dose (usually every 2 weeks) according to how you respond and the side effects you experience. The maximum dose is 9 g per night.

Food will decrease the amount of sodium oxybate that is absorbed by your body. Therefore, take this medication at least 2 hours after your last meal prior to bedtime. Take this medication only at bedtime and while in bed, as it may cause you to fall asleep too quickly. Do not walk around after taking this medication.

You need to take some steps to prepare this medication before taking it. Before taking this medication, read the Patient Package Insert for information about how to prepare and use this medication properly. If you are not sure how to prepare or use this medication, talk to your doctor or pharmacist.

There are 2 doses you need to prepare. Prepare both doses before bedtime. Your medication comes with a medication bottle, a measuring device, and written directions. Ask your pharmacist to provide 2 childproof containers to mix and store each dose. These containers will act as dosing cups.

Remove the cap on the medication bottle, insert the measuring device into the centre opening on the top of the medication bottle, and press down firmly. While holding the bottle and measuring device with one hand, draw up the prescribed dose with the other hand by pulling up on the plunger of the measuring device. Keep the medication bottle in the upright position while you are drawing up your dose.

Empty the contents of the measuring device into one of the dosing cups by pushing down on the plunger while holding the measuring device over the dosing cup. Add about 60 mL (2 ounces) of water to the dosing cup.

Repeat this process with the second dosing cup. Place the caps provided on the dosing cups and turn each cap to the right until it clicks and locks into its child-resistant position. Replace the cap on the bottle of medication and store it in a safe place out of the reach of children. Rinse out the liquid measuring device with water.

• Right before going to sleep, place your second dose in a secure location near your bed. You may need to set an alarm clock to wake you up for the second dose. Remove the cap from your first dosing cup by pressing down and turning to the left. Drink the entire first dose while sitting in bed, recap the cup, and then lie down right away.
• When you wake up 2.5 to 4 hours later, remove the cap from the second dosing cup. While sitting in bed, drink the entire second dose, recap the cup, and then lie down to continue sleeping.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor. Never change the dose of this medication yourself.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, skip the missed dose and continue with your normal dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature in the original bottle in a safe and secure place (locked up if appropriate), and keep it out of the reach of children and pets. After adding water, the medication should be used within 24 hours. Any unused medication should be returned to the pharmacy for proper disposal. Do not pour it down the drain. Always place your nightly doses of this medication safely out of the reach of children and pets.

Each mL of clear-to-slightly-opalescent oral solution USP contains 500 mg of sodium oxybate. Nonmedicinal ingredients: purified water and malic acid.

Do not use this medication if you:

• are allergic to sodium oxybate or any ingredients of this medication
• are using alcohol or any other sedatives, such as benzodiazepines (e.g., lorazepam, diazepam, clonazepam) or barbiturates (e.g., phenobarbital, butalbital)
• have succinic semialdehyde dehydrogenase deficiency, a rare metabolism disorder

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abnormal dreams
• acne
• bedwetting
• bruising
• chills
• dizziness
• dry mouth
• flu-like symptoms (sudden lack of energy, fever, cough, sore throat)
• frequent need to urinate
• hair loss
• headache
• hiccups
• increased sweating
• leg cramps
• mouth sores
• muscle aches, pain, weakness
• nausea
• sleeping problems
• vision changes
• vomiting
• weight loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• accidental injury or falls
• behaviour changes (e.g., aggression, anxiety, irritability, hostility)
• breathing problems (slow, shallow, or weak breathing)
• confusion
• decreased blood pressure
• depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• drowsiness during the day (hangover effect)
• enlarged abdomen
• fainting or loss of consciousness
• involuntary, rhythmic shaking
• irregular menstrual bleeding
• hallucinations (hearing or seeing things that aren’t there)
• high blood pressure
• loss of appetite leading to low body weight
• loss of feeling or sensation in an area of the body
• memory problems
• neck rigidity
• nervousness
• restlessness, inability to stay still
• sleepwalking
• stopping breathing while sleeping (sleep apnea)
• symptoms of dehydration (e.g., decreased urine, dry skin, dry and sticky mouth, sleepiness, dizziness, headache, thirst, confusion)
• symptoms of infection (fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• symptoms of withdrawal (e.g., anxiety, trouble sleeping, abnormal thinking)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizures
• symptoms of a severe allergic reaction, such as hives or shortness of breath
• thoughts of self harm or suicide

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast–feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Alcohol and other medications that cause drowsiness: Do not combine this medication with alcohol or other medications that cause drowsiness (e.g., antidepressants, sleeping pills, anxiety medications) since additional drowsiness can occur and be dangerous.

Bedwetting: This medication may cause bedwetting. If you experience this, contact your doctor. To help prevent bedwetting, make sure you go to the bathroom before taking your first dose of the night.

Breathing problems: If you have sleep apnea, snoring, or lung problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. This medication may cause breathing problems. If you experience difficulty breathing or stop breathing at night (sleep apnea) while taking this medication, contact your doctor.

Depression: This medication can cause depression. If you have depression or a history of depression, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Contact your doctor as soon as possible if you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, decreased interest in activities, or notice them in a family member who is taking this medication.

Drowsiness/reduced alertness: This medication should only be taken at bedtime. Do not drive, operate machinery, or perform other tasks that require mental alertness for at least 6 hours after taking this medication. When you first start taking this medication, do not drive or operate machinery if you feel drowsy or confused when you wake up.

Effects on thinking/mental effects: This medication may cause confusion, hallucinations, agitation, abnormal thoughts, depression, or other behaviour changes. If you experience these, contact your doctor.

Reduced liver function: Decreased liver function or liver disease can cause this medication to build up in the body, causing increased side effects. People with reduced liver function may require lower doses and close monitoring by their doctor.

Sleepwalking: Some people taking this medication experience confused behavior at night that is associated with wandering. In some instances, people have been injured while doing this. If this happens to you while you are taking this medication, contact your doctor.

Sodium content: This medication contains 91 mg of sodium per mL. If you are on a salt–restricted diet, or have high blood pressure or heart failure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Special considerations: This medication is a controlled substance. It is illegal to sell, distribute, or give this medication to anyone else, or to use this medication for reasons other than what your doctor prescribed it for.

This medication may be misused, which may lead to serious problems such as trouble breathing, seizures, loss of consciousness, coma, and death. Abuse of this medication may also lead to dependence, medication cravings, and severe withdrawal symptoms. While you are taking this medication, your doctor will want to see you at least once every 3 months to monitor for side effects.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are breast-feeding and taking sodium oxybate, it may affect your baby. Talk to your doctor about whether you should continue breast–feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

Seniors: There is limited experience with this medication for seniors. Your doctor will monitor you closely for side effects.

There may be an interaction between sodium oxybate and any of the following:

• alcohol
• antihistamines (e.g., azelastine, diphenhydramine, doxylamine, hydroxyzine, rupatadine)
• antipsychotics (e.g., aripiprazole, cariprazine, chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• barbiturates (e.g., phenobarbital, butalbital)
• benzodiazepines (e.g., alprazolam, lorazepam, diazepam, clonazepam)
• brimonidine
• buprenorphine
• buspirone
• butorphanol
• cannabis
• chloral hydrate
• clonidine
• dimenhydrinate
• diphenoxylate
• efavirenz
• entacapone
• esketamine
• general anesthetics (medications used to put people to sleep before surgery)
• guanfacine
• kava kava
• ketamine
• lemborexant
• methadone
• metoclopramide
• mirtazapine     
• muscle relaxants (e.g., baclofen, cyclobenzaprine, methocarbamol, orphenadrine, tizanidine)
• nabilone
• narcotic pain relievers (e.g., codeine, fentanyl, morphine, oxycodone, tapentadol, tramadol)
• olopatadine
• perampanel
• pizotifen
• pomalidomide
• pramipexole
• pregabalin
• ropinirole
• rotigotine
• scopolamine
• seizure medications (e.g., clobazam, gabapentin, levetiracetam, phenytoin, rufinamide, topiramate, valproic acid)
• sodium oxybate
• tetrabenazine
• thalidomide
• trazodone
• tricyclic antidepressants (e.g., amitriptyline, desipramine, nortriptyline)
• valerian
• zolpidem
• zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.