Modavigil (Modafinil)

Complete patient guide for uses, dosage, side effects, and safety information

Prescription Required

Quick Facts

Generic Name

modafinil

Drug Class

wakefulness-promoting agent

Used For

excessive daytime sleepiness from narcolepsy, sleep apnea, or shift work sleep disorder

How Taken

oral tablet, once or twice daily

What Is Modavigil Used For?

Modavigil helps improve wakefulness in people who experience excessive daytime sleepiness due to specific sleep disorders.

Primary Uses

Modavigil treats excessive daytime sleepiness associated with narcolepsy (sudden, irresistible tendency to fall asleep during normal waking hours), Obstructive Sleep Apnoea/Hypopnoea Syndrome (OSAHS), and moderate to severe chronic Shift Work Sleep Disorder (SWSD) when non-drug therapies have been unsuitable or unsuccessful.

How It Works

The exact way Modavigil works is not fully understood, but it acts on the central nervous system (the brain) and differs from other stimulant medicines. It increases wakefulness without causing the same effects as traditional stimulants.

Good to know: For sleep apnea, Modavigil only treats the sleepiness symptom – you should continue other treatments like Continuous Positive Airway Pressure unless your doctor says otherwise.

How to Take Modavigil

Take Modavigil exactly as your doctor prescribes. Each tablet contains 100mg of modafinil.

Dosage Instructions

For narcolepsy or sleep apnea: usual dose is 200mg to 400mg daily (2-4 tablets). Take either as two separate doses (morning and midday) or as one morning dose. Don’t take after midday or you may have trouble sleeping. For shift work sleep disorder: take 200mg (2 tablets) as a single dose 1 hour before starting your shift. Swallow tablets whole with water. Your doctor may start with a lower dose and increase gradually.

What If You Miss a Dose?

If you miss a dose, just take your next dose at the usual time. Don’t take an extra dose to catch up.

Important: Don’t exceed the recommended daily dose unless your doctor tells you to. This medicine is only for you – never give it to anyone else.

Available Tablet Strengths

100mg

100mg Tablet White, Capsule-shaped • 100

Side Effects

Like all medications, this medicine can cause side effects. Most are mild and temporary, but some require medical attention.

Common Side Effects

These side effects occur relatively frequently and usually don’t require emergency care:

Headache
Nausea
Diarrhea
Dry mouth
Poor appetite
Runny nose
Sore throat
Nervous feeling
Dizziness
Back pain
Feeling anxious
Upset stomach
Trouble sleeping

Seek immediate medical attention if you experience:

Skin rash, hives, mouth sores, or skin blistering and peeling
Swelling of face, eyes, lips, tongue or throat
Trouble swallowing or breathing
Fever, shortness of breath, leg swelling, yellowing of skin or eyes, dark urine
Mental symptoms including depression, anxiety, aggression, agitation, irritability, hallucinations, mania, thoughts of suicide
Chest pain or abnormal heart beats
Fits or convulsions

Important Warnings

There are important situations where Modavigil should not be used and conditions your doctor needs to know about.

Who Should Not Take Modavigil

Don’t take Modavigil if you’re allergic to modafinil or any ingredients, are pregnant, planning pregnancy, likely to become pregnant, or breastfeeding. Don’t use if packaging is damaged or tablets look wrong, or if past expiry date.

Medical Conditions to Discuss

Tell your doctor if you’re under 18 or over 65, have mental health problems, heart conditions (angina, heart attack, enlarged heart), irregular heart rhythm, high blood pressure, kidney or liver problems, are taking hormonal contraceptives, receiving anxiety treatment, taking brain stimulants, depression medications, epilepsy medicines, antifungal medications, sedatives, rifampicin, cyclosporin, propranolol, warfarin, theophylline, or any other medicines.

Pregnancy and Breastfeeding

Modafinil is suspected to cause birth defects if taken during pregnancy. If you could become pregnant, confirm with a pregnancy test that you’re not pregnant within a week before starting treatment. If you become pregnant while taking Modavigil, stop immediately and tell your doctor. Don’t take while breastfeeding.

Serious Skin Reactions: Stop Modavigil and get emergency treatment immediately if you develop skin rash, hives, mouth sores, skin blistering/peeling, wheezing, breathing difficulty, or swelling.

Drug Interactions

Modavigil can interact with several medications. Always tell your doctor about all medicines you’re taking.

Birth Control Warning: Modavigil reduces effectiveness of hormonal contraceptives. Use additional non-hormonal birth control while taking Modavigil and for 2 months after stopping.

Hormonal contraceptives (birth control pills, implants, injections, some IUDs)
Depression medications including MAOIs
Epilepsy medications (phenytoin, carbamazepine, phenobarbitone)
Antifungal medicines (ketoconazole, itraconazole)
Sleep medications (sedatives)
Rifampicin (tuberculosis antibiotic)
Cyclosporin (organ transplant medicine)
Propranolol (blood pressure/heart medicine)
Warfarin (blood thinner)
Theophylline (asthma medicine)
Brain stimulants like methylphenidate

Alcohol & Driving

Take precautions with activities requiring alertness until you know how Modavigil affects you.

Alcohol

The source does not provide specific information about alcohol interactions with Modavigil.

Driving and Operating Machinery

Don’t drive or operate machinery until you know how Modavigil affects you.

Storage

Keep Modavigil tablets in their original pack until time to take them. Store below 25°C in a cool, dry place away from direct heat and sunlight. Don’t store in the bathroom or near a sink. Keep where children cannot reach them – a locked cupboard at least one-and-a-half metres above ground is ideal.

Overdose Information

If you think you or anyone else has taken too much Modavigil, immediately call your doctor, Poisons Information Centre (13 11 26 in Australia or 0800 764 766 in New Zealand), or go to the nearest hospital emergency department. Do this even if there are no signs of discomfort or poisoning.

Frequently Asked Questions

The source doesn’t specify onset time, but for shift work sleep disorder, you should take it 1 hour before starting your shift, suggesting it begins working within that timeframe.

The source doesn’t mention food restrictions. You should swallow the tablets whole with a little water, but no specific food instructions are provided.

The source notes that Modavigil differs from other stimulant medicines and doesn’t cause the same ‘high’ feeling that other narcolepsy stimulants may cause, but doesn’t specifically address addiction potential.

The source doesn’t provide specific information about stopping Modavigil suddenly, but mentions that if you’re switching from other narcolepsy treatments, your doctor will advise how to withdraw from those treatments.

The source doesn’t provide specific information about alcohol interactions with Modavigil. You should ask your doctor about alcohol use while taking this medication.

Poor appetite is listed as a common side effect, which could potentially affect weight, but the source doesn’t specifically mention weight gain or loss.