NZ Formulary



What does it do?

Primidone is used to treat and prevent seizures. It is also sometimes used for other conditions.

How should you take it?

Take primidone regularly as directed with a glass of water.

What if you forget a dose?

Take the missed dose as soon as possible and continue as directed.

Can you take other medicines?

Primidone can react with many medicines, sometimes with severe results.

Tell your pharmacist or doctor about all medicines or treatments that you may be taking including vitamins, herbal products or recreational drugs.

Important information continues on next page.

What side effects might you notice?

Side EffectsRecommended action

Skin rash, skin peeling or blisters

Stop taking and see your doctor immediately

Suicidal thoughts

Slow or shallow breathing, hard to wake up

Reduced number of blood cells that fight infections or help your blood to clot - symptoms include: fever, chills, sore throat or generally feeling unwell, or easy or unusual bruising or bleeding

Symptoms of liver problems including: yellow skin or eyes, itching, dark urine, pale bowel motions, abdominal pain

Tell your doctor immediately

Agitation, confusion, loss of co-ordination/walking or handwriting problems, mood changes, slurred speech, trouble concentrating, unusual behaviour or thinking

Changes in vision

Tell your doctor

Dizziness, drowsiness, headache

Tell your doctor if troublesome

Stomach upset

Take with food

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have liver problems or sleep apnoea.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Some contraceptives may not work as well while you are taking primidone, and for 4 weeks after stopping. Discuss with your doctor or pharmacist.
  • Primidone can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)
  • Long-term use of primidone may weaken your bones.
  • Do not stop taking primidone without talking to your doctor first, unless you have a skin rash (see Side Effects).