Mysoline is used for:

• Treating and preventing seizures. It may be taken alone or with other medicines. It may also be used for other conditions as determined by your doctor.
• Mysoline is an anticonvulsant. It works by decreasing nerve impulses in the nervous system, which helps to reduce seizures.

Do NOT use Mysoline if:

• you are allergic to any ingredient in Mysoline or to phenobarbital
• you have the blood disease porphyria
• you are taking sodium oxybate (GHB)

Contact your doctor or health care provider right away if any of these apply to you.

Before using Mysoline:

Some medical conditions may interact with Mysoline. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have a history of drug abuse or dependence, mental or mood problems (eg, depression), or suicidal thoughts or behaviors
• if you have liver problems, lung problems, or breathing problems
• if you will be receiving anesthesia (eg, methoxyflurane)

Some MEDICINES MAY INTERACT with Mysoline. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Sodium oxybate (GHB), stiripentol, or valproic acid because the risk of severe side effects such as severe drowsiness and incoordination may be increased
• Anticoagulants (eg, warfarin), aromatase inhibitors (eg, exemestane), beta-blockers (eg, propranolol), clozapine, corticosteroids (eg, prednisone), doxycycline, epothilones (eg, ixabepilone), oestrogen, griseofulvin, HIV protease inhibitors (eg, darunavir, lopinavir), hydantoins (eg, phenytoin), mammalian target of rapamycin (MTOR) inhibitors (eg, everolimus), maraviroc, metronidazole, nonnucleoside reverse transcriptase inhibitors (NNRTIs) (eg, etravirine), oral contraceptives (eg, birth control pills), quinidine, tacrolimus, teniposide, theophylline, tolvaptan, or tyrosine kinase inhibitors (eg, lapatinib) because their effectiveness may be decreased by Mysoline

This may not be a complete list of all interactions that may occur. Ask your health care provider if Mysoline may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Mysoline:

Use Mysoline as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Mysoline by mouth with or without food. If stomach upset occurs, take with food to reduce stomach irritation.
• Take Mysoline on a regular schedule to get the most benefit from it.
• Taking Mysoline at the same time each day will help you remember to take it.
• Do not suddenly stop taking Mysoline. You may have an increased risk of side effects (eg, seizures). If you need to stop Mysoline or add a new medicine, your doctor will gradually lower your dose.
• Continue to take Mysoline even if you feel well. Do not miss any doses.
• If you miss a dose of Mysoline, take it as soon as possible. If it is within 1 hour of your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Mysoline.

Important safety information:

• Mysoline may cause drowsiness, dizziness, lightheadedness, and vision changes. These effects may be worse if you take it with alcohol or certain medicines. Use Mysoline with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Mysoline may contain tartrazine dye (FD & C Yellow No. 5). This may cause an allergic reaction in some patients. If you have ever had an allergic reaction to tartrazine, ask your pharmacist if your product has tartrazine in it.
• It may take several weeks for Mysoline to work well. Do not stop taking Mysoline without talking with your doctor.
• Patients who take Mysoline may be at increased risk for suicidal thoughts or actions. The risk may be greater in patients who have had suicidal thoughts or actions in the past. Watch patients who take Mysoline closely. Contact the doctor at once if new, worsened, or sudden symptoms such as depressed mood; anxious, restless, or irritable behavior; panic attacks; or any unusual change in mood or behavior occur. Contact the doctor right away if any signs of suicidal thoughts or actions occur.
• Hormonal birth control (eg, birth control pills) may not work as well while you are using Mysoline. To prevent pregnancy, use an extra form of birth control (eg, condoms).
• Tell your doctor or dentist that you take Mysoline before you receive any medical or dental care, emergency care, or surgery.
• Lab tests, including complete blood cell counts, may be performed while you use Mysoline. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• PREGNANCY and BREAST-FEEDING: Mysoline may cause harm to the fetus. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Mysoline while you are pregnant. Mysoline is found in breast milk. Do not breast-feed while taking Mysoline.
• If you suddenly stop taking Mysoline, you may experience WITHDRAWAL symptoms, including anxiety, dizziness, hallucinations, lightheadedness, muscle twitching, nausea, seizures, sleeplessness, trembling hands and fingers, vomiting, or weakness.

Possible side effects of Mysoline:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

• Dizziness; drowsiness; lightheadedness; loss of appetite; loss of coordination; nausea; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

• Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); decreased sexual ability; double vision or unusual eye movements; fever; measles-like rash; new or worsening mental or mood changes (eg, anxiety, depression, restlessness, irritability, panic attacks, behavior changes, suicidal thoughts or attempts); new or worsening seizures; unusual tiredness or weakness.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.

If you have any more questions please ask your Pharmacist.

Remember to keep all medicines out of reach of children
Please Note: We have made every effort to ensure that the content of this information sheet is correct at time of publish, but remember that information about drugs may change. This sheet does not list all the uses and side-effects associated with this drug. For full details please see the drug information leaflet which comes with your medicine. Your doctor will assess your medical circumstances and draw your attention to any information or side-effects which may be relevant in your particular case.

References:

https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=af593171-dabb-4ea3-b44c-89ed457b2c46

http://www.rxlist.com/mysoline-drug.htm

http://www.drugs.com/cdi/mysoline.html

https://en.wikipedia.org/wiki/Primidone

http://www.medicinenet.com/primidone-oral/article.htm

http://www.fda.gov/downloads/Drugs/DrugSafety/UCM222370.pdf

http://www.emedicinehealth.com/drug-primidone/article_em.htm