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Mysoline 50 mg and 250 mg Tablets
Read all of this leaflet carefully before you start using this
Keep this leaflet. You may need to read it again.
If you have any further questions, ask your doctor or pharmacist.
This medicine has been prescribed for you. Do not pass it on to
others. It may harm them, even if their symptoms are the same
as yours.
If any of the side effects gets serious, or if you notice any side
effects not listed in this leaflet, please tell your doctor or
In this leaflet:
1. What Mysoline is and what it is used for
2. Before you use Mysoline
3. How to use Mysoline

4. Possible side effects
5. How to store Mysoline
6. Further information

Mysoline contains primidone as the active ingredient; this belongs to a group of
medicines used to treat seizures.
Mysoline is used for the treatment of certain types of epilepsy, seizures (fits) or shaking
attacks (essential tremor).

Do not take Mysoline if you:
• are allergic (hypersensitive) to primidone, a substance called phenobarbitone, or to
any of the other ingredients of Mysoline (these are listed in Section 6: Further
• have porphyria (a rare inherited disorder of metabolism) or anyone in your family has it.

Take special care with Mysoline if you:
• have ever had problems with your breathing, kidneys or liver.
• are pregnant or are trying to become pregnant (see beneath for further information)
If you go into hospital, tell the medical staff that you are taking Mysoline.
A small number of people being treated with anti-epileptics such as primidone have had
thoughts of harming or killing themselves. If at any time you have these thoughts,
immediately contact your doctor.

Taking other medicines
Please tell your doctor if you are taking or have recently taken any other medicines,
including medicines obtained without a prescription. This is important because some
medicines may affect the way Mysoline works, or Mysoline may affect the way other
medicines work.
In particular, tell your doctor if you are taking any of the following:
• Other medicines used to treat epilepsy and other types of seizures (such as
phenytoin, felbamate, sodium valproate, carbamazepine, ethosuxamide,
oxcarbazepine, tiagabine, topiramate, zonisamide)
• Anticoagulants to prevent blood clots (such as warfarin)
• Barbiturates (such as sleeping tablets)
• Methadone (used to treat severe pain, cough, or as a substitute for morphine
• Herbal remedies containing St John’s Wort
• Antibiotics (such as chloramphenicol, metronidazole, doxycycline)
• Antiviral medicines (such as nelfinavir)
• Asthma medicines (such as theophylline, montelukast)
• Hormone containing medicines (such as the oral contraceptive pill)
• Medicines used to treat high blood pressure or heart conditions (such as betablockers, digitoxin, losartan, nimodipine, quinidine)
• Cyclosporin (used to prevent rejection of an organ transplant and also for other
diseases of the body’s immune system)
• Medicines used to treat mental health problems or depression (such as clozapine,
lamotrigine, mianserin, tricyclic antidepressants)
• Steroid-containing medicines
• Medicines used to treat cancer (such as cyclophosphamide, etoposide)
• Granisetron (used to treat severe nausea and vomiting)
• Medicines used during an anesthetic for surgery (such as rocuronium, vecuronium)
• Medicines containing morphine, or similar medicines called opiates
Mysoline may increase the toxic effect on the liver of an overdose of paracetamol.

Taking Mysoline with food and drink
Alcohol can react with Mysoline. Ask your doctor for advice if you want to drink alcohol.

Pregnancy and breast-feeding
Ask your doctor for advice before taking any medicine.
The use of Mysoline in pregnancy is associated with an increased risk of abnormalities in
babies. Therefore, you must tell your doctor if you are pregnant, or trying to become
pregnant because Mysoline has the potential to harm your unborn child.
Pregnant women can have reduced folic acid in their blood whilst taking Mysoline. In
addition, the new born child may develop withdrawal symptoms if the mother has taken
Mysoline in the late stages of pregnancy. Blood clotting problems have occurred
occasionally in children born to women who were previously taking anticonvulsant drugs.
Tell your doctor if you are breast-feeding because Mysoline may cause your baby to be
very sleepy.

Driving and using machines
Mysoline can make you feel sleepy. If so, do not drive or operate machinery.

Always take Mysoline exactly as your doctor has told you. You should check with your
doctor or pharmacist if you are not sure.
Swallow the tablets whole with a drink of water.
Mysoline is normally taken twice a day. Try to take your tablets at the same time each day.

At first, your dose may be as little as 125 mg (half a 250 mg tablet). This will be adjusted
by your doctor until your condition is controlled. Typical maintenance doses are as follows:
Age group

Daily dose (milligrams)

Adults and children over 9 years
Children 6 to 9 years
Children 2 to 5 years
Children up to 2 years

750 to 1500
750 to 1000
500 to 750
250 to 500

Elderly / Patients with low physical strength
Lower doses may be prescribed.

Shaking attacks (essential tremor)
Your starting dose may be 50 mg. This will be adjusted by your doctor until your condition
is controlled. The maximum daily dose for shaking attacks (essential tremor) is 750 mg.

If you take more Mysoline than you should
If you take more than your normal dose, contact your doctor or nearest hospital.

If you forget to take Mysoline
If you miss a dose, take it as soon as you remember. Do not take a double dose to make
up for a forgotten tablet.

If you stop taking Mysoline
Do not stop taking your Mysoline, even if you are feeling well, unless your doctor tells you
to. You may have become dependent on Mysoline, and therefore you could get a
withdrawal reaction if you stop treatment too quickly. Mysoline treatment should be
reduced gradually to prevent this.
If you have any further questions on the use of this product, ask your doctor or

Like all medicines, Mysoline can cause side effects, although not everybody gets them.
When first taking Mysoline, drowsiness and lack of energy may occur; these usually pass.
There have been reports of bone disorders including osteopenia and osteoporosis
(thinning of the bone) and fractures. Check with your doctor or pharmacist if you are on
long-term antiepileptic medication, have a history of osteoporosis, or take steroids.
Common side effects
Uncommon side effects
(affecting fewer than 1 in every 10 people)
(affecting fewer than 1 in every 100 people)
• disturbances of vision
• nausea and vomiting
• dizziness
• headache
• jerky movements
• skin rash
• rolling of the eyes
Rare side effects (affecting fewer than 1 in every 1000 people)
• joint or bone pain
• changes in mood or behaviour.
• severe skin reactions affecting large portions of your body including redness, pain,
ulcers, blisters, shedding the outer layer of skin or involvement of lips or the lining of
the mouth, nostrils or ears (e.g. toxic epidermal necrolysis, Stevens-Johnson
• a disease called lupus erythematosus which causes inflammation of various parts of
the body including the skin, joints, lungs, kidneys, heart, and liver.
• development of Dupuytren’s contracture (a thickening of fibrous tissue in the palm of
the hand that causes one or more fingers to draw back).
• abnormalities of the blood cells; if you notice a pale appearance of your skin, abnormal
bleeding or tendency to bruising, fever or sore throat please consult your doctor.
• raised levels of enzymes in your liver.
Do not be alarmed by this list of possible events. You may not have any of them.
If any of the side effects gets serious, or you notice any side effects not listed in this
leaflet, please tell your doctor or pharmacist.

Keep out of the reach and sight of children
Keep your tablets below 25°C.
Do not use Mysoline after the expiry date which is stated on the carton as {EXP
MM/YYYY}. The expiry date refers to the last day of that month.
Medicines should not be disposed of via wastewater or household waste. Ask your
pharmacist how to dispose of medicines no longer required. These measures will help to
protect the environment.

What Mysoline contains
The active substance is primidone. Each tablet contains 50 mg or 250 mg of primidone.
The other ingredients are carmellose calcium, gelatin, magnesium stearate, povidone K30
and stearic acid, which are all typical ingredients used in tablet manufacture.

Marketing Authorisation Holder
Laboratoires SERB,
40, avenue George V,
75008 Paris,

Recipharm Limited,
Vale of Bardsley,
Lancashire, OL7 9RR,

This leaflet was last approved in July 2012.

Is this leaflet hard to see or read? Phone 0800 198 5000 for help


What Mysoline looks like and contents of the pack
Mysoline 50 mg Tablets are white uncoated tablets for oral use. One side of the tablet has a
single letter 'M'. The other side of the tablet is plain.
Mysoline 250 mg Tablets are white uncoated tablets for oral use. One side of the tablet
has the letter 'M' either side of a break-line. The other side of the tablet is plain.
Mysoline comes in containers of 100 tablets.

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Source: Medicines and Healthcare Products Regulatory Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.