What does it do?

Phenytoin is used to treat and prevent seizures.

Before you start

• Tell your doctor if you have liver problems.
• Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

How should you take it?

Take phenytoin regularly as directed.
Capsule: Take with a glass of water.
Chewable tablet (Infatabs®): You can either swallow these whole with a drink of water, or chew them.
Liquid: Measure carefully with an oral syringe or measuring spoon. Shake the bottle well before measuring each dose.

What if you forget a dose?

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

Can you take other medicines?

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

Remember to tell your pharmacist or doctor you are taking phenytoin before starting any other medicines or treatments, including over-the-counter medicines, vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side Effects	Recommended action
Skin rash, skin peeling or blisters	Stop taking and see your doctor immediately
Suicidal thoughts 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
Unusual eye movements Loss of co-ordination/walking or handwriting problems, trouble concentrating, confusion, slurred speech	Tell your doctor
Dizziness, drowsiness More body and facial hair	Tell your doctor if troublesome
Enlarged, tender or bleeding gums	Brush and floss your teeth regularly, and see your dentist regularly.
Stomach upset	Take with food

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

Other information:

• Some contraceptives may not work as well while you are taking phenytoin, and for 4 weeks after stopping. Discuss with your doctor or pharmacist.
• Phenytoin 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?)
• You may need blood tests from time to time to make sure you are taking the right dose of phenytoin.
• Long-term use of phenytoin may weaken your bones.
• Do not stop taking phenytoin without talking to your doctor first, unless you have a skin rash (see Side Effects).