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What does it do?

Modafinil is used to treat narcolepsy and other sleep disorders.

How should you take it?

Take modafinil as directed with a glass of water. Take modafinil in the morning, or in the morning and at noon if you are taking it twice a day, so you can sleep at night.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time. Do not take close to bedtime.

Can you take other medicines?

Some medicines available without a prescription may react with modafinil including:

  • levonorgestrel emergency contraceptive pill (e.g. Postinor-1®)

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

What side effects might you notice?

Side EffectsRecommended action

Fast or irregular heartbeat, chest pain

Symptoms of allergy including: skin rash, itching, swelling, trouble breathing

Tell your doctor immediately

Anxiety, agitation, unusual behaviour or thinking, low mood, confusion

Changes in vision

Strange or uncontrolled movements

Tell your doctor

Trouble sleeping, headache

Chills, sweating, tingling or numbness

Loss of appetite, dry mouth, stomach upset

Tell your doctor if troublesome

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

Other information:

  • Tell your doctor if you have heart or liver problems, high blood pressure or a mood disorder.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • If you are taking an oral contraceptive you will need to use additional birth control methods while taking modafinil, and for four weeks after stopping. Talk to your doctor.
  • Modafinil may make you dizzy or sleepy and make it dangerous to drive, operate machinery or do other activities that require you to be alert. Limit alcohol intake because it can increase these effects.

This leaflet contains important, but not all, information about this medicine.

Prepared by the PILs Committee at Christchurch Hospital, Canterbury District Health Board, New Zealand. December 2017

For more general information about this sheet and its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at the Canterbury District Health Board. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed