Skip to Content


Active substance: PRIMIDONE

View full screen / Print PDF » Download PDF ⇩
Mysoline® 250 mg Tablets


The name of your medicine is Mysoline 250mg Tablets but will be referred
to as Mysoline throughout this leaflet.
Read all of this leaflet carefully before you start using this medicine.
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 pharmacist.
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 may increase the toxic effect on the liver of an overdose of
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

Mysoline tablets contain primidone as the active ingredient; this belongs to
the group of medicines used to treat seizures.

Always take Mysoline exactly as your doctor has told you. You should
check with your doctor or pharmacist if you are not sure.

Mysoline is used for the treatment of certain types of epilepsy, seizures
(fits) or shaking attacks (essential tremor).

Swallow the tablets whole with a drink of water.

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 information)
- 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
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 addiction)
- 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
beta-blockers, 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,
- Medicines containing morphine, or similar medicines called opiates

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

750 to 1500

Children 6 to 9 years

750 to 1000

Children 2 to 5 years

500 to 750

Children up to 2 years

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
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 pharmacist.

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.
Common side effects (affecting fewer than 1 in every 10 people)
- disturbances of vision
- dizziness
- jerky movements
- rolling of the eyes.
Uncommon side effects (affecting fewer than 1 in every 100 people)
- nausea and vomiting
- headache
- skin rash.
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 syndrome)
- 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
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
Reporting of side effects
If you get any side effects, talk to your doctor, pharmacist or nurse. This
includes any possible side effects not listed in this leaflet. You can also
report side effects directly via the Yellow Card Scheme at:
By reporting side effects, you can help provide more information on the
safety of this medicine.
Keep out of the sight and reach of children.
Do not store above 25oC.
Protect from light and moisture.
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.
If your tablets become discoloured or show any other signs of deterioration,
consult your doctor or pharmacist who will tell you what to do.
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
Each tablet contains 250mg of primidone.
The other ingredients are carmellose calcium, gelatin, magnesium stearate,
povidone and stearic acid.
What Mysoline looks like and contents of the pack
Mysoline tablets are available as white round tablets. One side of the tablet
has the letter ‘M’ either side of a break-line and plain on the other side.
Mysoline are available in blister strip packs of 50 and 100 tablets.

Mysoline tablets are manufactured by Recipharm Limited, Vale of Bardsley,
Ashton-under-Lyne, Lancashire, OL7 9RR, UK.
Procured from within the EU by Product Licence holder
Star Pharmaceuticals Ltd., 5 Sandridge Close, Harrow, Middlesex, HA1
1XD. Repackaged by Servipharm Ltd.

PL No: 20636/2609

Leaflet revision and issue date (Ref.) 11.11.14[3]
* Mysoline® and SERB are trademarks of SERB.

Expand view ⇕

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.