Modafinil

About Modafinil

• Modafinil prevents feelings of excessive sleepiness
• Modafinil is prescribed for people who fall asleep during the day due to narcolepsy, or those who work night shifts or have a changing shift pattern
• Modafinil is also prescribed for some patients with obstructive sleep apnoea
• Modafinil is often prescribed on a short term basis, as some people experience feelings of dependence when Modafinil is taken for long periods
• Modafinil is sometimes known by its brand name of Provigil
• It is important to read the patient leaflet for a full list of side effects and cautions.

How Does Modafinil Work?

Modafinil alters the amount of certain chemicals within the brain. These chemicals have an impact on the part of the brain that controls how alert you feel. This leads to feelings of wakefulness. 

The body can become accustomed to the effect of modafinil, making you feel dependent on it if you take it for a long time. This also means that stopping it can lead to feelings of withdrawal. This is why you should only take modafinil as prescribed by your doctor, and attend for regular reviews to check that modafinil is still appropriate for you.

How is Modafinil Taken?

Modafinil is available in tablet form. It should be swallowed with some water, and can be taken with or without food. 

If you are taking modafinil for narcolepsy or sleep apnoea, you will most likely take it once a day in the morning to help you feel more awake during the day.

If you are taking modafinil for sleepiness associated with working night shifts or a changing shift pattern, you will probably take it just before you start your shift to help you feel more awake at work.

Modafinil is not an alternative to getting enough sleep, and so it should not be used in place of good sleep habits. 

Dosage of Modafinil

The usual starting dose of modafinil is 200mg each day. 

However, some people may require up to 400mg each day. When taking 400mg, Modafinil can be taken as one dose, or split between a morning and lunchtime dose for those taking it for narcolepsy or sleep apnoea. Shift workers may also take a split dose, but the timing of the doses will depend on the time of each shift.

Are there any Side Effects?

Like all medications, modafinil can have some side effects. The most common side effects include:

• Headache
• Dizziness
• Trouble falling asleep or staying asleep
• Nausea (feeling sick)
• Diarrhoea or constipation
• Loss of appetite
• A dry mouth, or a strange taste in your mouth.

If any of these side effects persist or are troublesome, you should speak to your doctor.

Occasionally, more serious side effects can occur including:

• Confusion
• Nosebleeds
• Sweating
• Back pain
• Tight, achy muscles, or difficulty moving
• Uncontrollable shaking
• Changed sensations of the skin including tingling or numbness
• Changes to eyesight or pain in your eyes
• Feeling abnormally excited
• Anxiety or depression, or thoughts of harming yourself.

If any of these side effects occur, you should speak to a doctor straight away.

If you have a severe allergic reaction (anaphylaxis) including breathlessness, lip or tongue swelling, call 999 immediately.

Modafinil Warnings

Modafinil may not be suitable for everyone. You should tell your doctor if you:

• Have ever had an allergic reaction to a medication in the past
• Have liver or kidney disease
• Have high blood pressure
• Have an abnormal heart rhythm (cardiac arrhythmia)
• Have a mental health condition including psychosis, depression, anxiety, or bipolar disorder
• Have ever attempted suicide or had suicidal ideation
• Have a history of insomnia (difficulty sleeping)
• Use hormonal contraceptives to prevent pregnancy
• Are pregnant, trying to conceive, or breastfeeding
• Have, or have ever had, drug or alcohol dependence.

Some medications can interact with modafinil. You may be advised that modafinil will not suit you if you already take:a

• Medications for epilepsy
• Contraceptive medications
• Antidepressants
• Blood thinning medications
• Certain medications for heartburn or acid reflux
• Benzodiazepines such as diazepam
• Beta blockers including propranolol
• Certain antifungal medications.

Modafinil can affect the efficacy of contraceptives. Another form of contraception should be used whilst taking modafinil, and for one month after stopping it. Modafinil is unsuitable for women who are trying to conceive, already pregnant, or breastfeeding.

You should also tell your prescriber about any herbal remedies or supplements you take. This will allow your prescriber to check that modafinil will not interact with them.

It is important that your doctor checks that modafinil will suit you. Your doctor should complete a thorough health questionnaire and review your current medications before prescribing this medication.