Primidone (prim-e-doan)

Consumer Medicine Information


This leaflet answers some of the common questions people ask about Mysoline. It does not contain all the information that is known about Mysoline.

It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor will have weighed the risks of you taking Mysoline against the benefits they expect it will have for you.

If you have any concerns about taking this medicine, ask your doctor or pharmacist.

Keep this leaflet with the medicine. You may need to read it again.


Mysoline is used to control epilepsy. Epilepsy is a condition where you have repeated seizures (fits). There are many different types of seizures, ranging from mild to severe.

Mysoline is a barbiturate and belongs to a group of medicines called antiepileptics. These medicines are thought to work by controlling brain chemicals which send signals to nerves so that seizures do not happen.

Mysoline may be used alone, or in combination with other medicines, to treat your condition.

Follow all directions given to you by your doctor. They may differ from the information in this leaflet.

Your doctor may prescribe this medicine for another use. Ask your doctor if you want more information.


When you must not use it

Do not take Mysoline after the use by (expiry) date printed on the pack. It may have no effect at all or an unexpected effect if you take it after the expiry date.

Do not take Mysoline if the packaging is torn or shows signs of tampering.

Do not use it to treat any other complaints unless your doctor tells you to.

Do not give this medicine to anyone else even if they have the same condition as you.

Before you start to use it

You must tell your doctor if:

  1. You have any allergies to:
    – Primidone or any other barbiturates
    – Other medicines used to treat fits or epilepsy
    – Any of the other ingredients listed at the end of this leaflet
    – Any other medicines
    – Any other substances, such as foods, preservatives or dyes
    If you have an allergic reaction, you may experience a skin rash, hayfever, difficulty breathing or feel faint.
  2. You have or have ever had:
    – Porphyria (a rare blood pigment disorder)
    – Liver problems
    – Kidney problems
    – Lung problems

Your doctor will decide if you should take Mysoline if you have any of these conditions.

If you are pregnant or intend to become pregnant while taking Mysoline, you must talk to your doctor. Mysoline may affect your developing baby if you take it during pregnancy. However, it is very important to control your fits while you are pregnant.

If it is necessary for you to take Mysoline, your doctor can help you decide whether or not to take it during pregnancy.

Talk to your doctor before breastfeeding while taking Mysoline. Mysoline passes into breast milk and may affect your baby.

If you do breastfeed, watch your baby carefully. If your baby becomes sleepy don't breastfeed again until you speak to your doctor.

Taking other medicines

Tell your doctor if you are taking any other medicines, including:

  • Medicines for epilepsy or convulsions
  • Medicines used to thin your blood eg. warfarin
  • Oral contraceptives (birth control pills)
  • Any medicines that you buy at the chemist, supermarket or health food shop.

These medicines may be affected by Mysoline, or may affect how well it works.

Your doctor or pharmacist can tell you what to do if you ar