A wakefulness-promoting medicine
Armodafinil
A wakefulness-promoting medicine, the longer-lasting component of modafinil, used for excessive daytime sleepiness.
What is Armodafinil?
Armodafinil is a wakefulness-promoting medicine closely related to modafinil; it is the longer-lasting active component of modafinil. It is used to reduce excessive daytime sleepiness, mainly in narcolepsy and sometimes in sleepiness linked to shift work or obstructive sleep apnoea. It is started by a specialist and taken once in the morning. Like modafinil, it can cause headache, can rarely trigger a serious skin rash (stop and seek help), and reduces the reliability of hormonal contraception, so extra methods are needed. It is not recommended in pregnancy.
Education and reference only. This is a plain-language guide to Armodafinil — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Armodafinil is a wakefulness-promoting medicine very closely related to modafinil. Modafinil contains two mirror-image forms, and armodafinil is the single, longer-lasting form, so it works in much the same way but can last longer in the body. It is used to reduce excessive daytime sleepiness, chiefly in narcolepsy and sometimes in sleepiness related to shift work or obstructive sleep apnoea. It is specialist-initiated and taken as a tablet, usually once in the morning.
How it works
Like modafinil, armodafinil acts on the brain's sleep-wake systems to promote alertness without the strong stimulant effects of older medicines. Because it is the longer-lasting component, it can keep people alert for an extended part of the day from a single morning dose. It reduces daytime sleepiness rather than curing the underlying condition, so it is used alongside good sleep habits and treatment of any cause.
Company & origin
Originated / developed by: Generic (originally Cephalon).
A wakefulness-promoting medicine closely related to modafinil, used to reduce excessive daytime sleepiness.
Practical use
How to take Armodafinil
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it by mouth once in the morning, as your specialist directs, so it does not disturb your sleep at night.
- Because it lasts longer than modafinil, avoid taking it later in the day unless specifically advised.
- Use extra or alternative contraception if you could become pregnant, as it makes hormonal contraception less reliable.
- Do not stop the medicine suddenly without advice; your specialist will guide any changes.
- Stop the medicine and seek urgent help if you develop a spreading rash, blistering, peeling skin, mouth sores or facial swelling.
Weighing it up
Advantages & disadvantages of Armodafinil
Advantages
- Reduces excessive daytime sleepiness and, as the longer-lasting form, can give alertness across much of the day from one dose.
- Tends to cause fewer jittery, stimulant-type effects than older wakefulness medicines.
- Taken once a day by mouth, which is convenient.
Disadvantages
- Commonly causes headache, and can cause nausea, nervousness or a faster heartbeat.
- Can rarely trigger a serious skin or allergic reaction needing urgent care.
- Reduces the reliability of hormonal contraception and is not recommended in pregnancy.
Practical use
Good to know
Armodafinil is started and supervised by a specialist and works in much the same way as modafinil, sharing the same cautions. The most common side effect is headache, and some people notice nausea, nervousness or a faster heartbeat. As with modafinil, it can rarely cause a serious skin or allergic reaction: if you develop a spreading rash, blistering, peeling skin, mouth sores or facial swelling, stop the medicine and seek urgent help. It also reduces the reliability of hormonal contraception, so additional or alternative methods are needed during treatment and for a while afterwards, and it is not recommended in pregnancy. Do not stop suddenly without advice, and report chest pain, palpitations or new mood changes.
Who should not take it / use with caution
- People with certain heart-rhythm problems or uncontrolled high blood pressure should not usually take it.
- It is not recommended in pregnancy, and people relying only on hormonal contraception need additional cover.
- Used with caution in those with a history of serious skin reactions, severe anxiety or psychiatric illness.
Monitoring
- Reviewing how well daytime sleepiness is controlled and whether the medicine is still needed.
- Checking blood pressure and heart rate, particularly when starting or changing the dose.
- Watching for skin reactions, mood changes and ensuring reliable contraception is in place.
Side effects
- Headache is the most common effect; nausea, dry mouth, nervousness and difficulty sleeping can also occur.
- A faster or stronger heartbeat, dizziness or raised blood pressure in some people.
- Rarely, a serious skin rash or allergic reaction, or new anxiety, low mood or other mood changes, which need prompt review.
Key interactions
- Reduces the reliability of hormonal contraception such as the pill, patch and implant, so extra methods are needed.
- Can affect the levels of some other medicines, including certain anticoagulants and epilepsy medicines.
- Caution with other stimulants and with medicines that affect blood pressure or heart rate.
Available as: Tablets taken by mouth.
Answers
Armodafinil: frequently asked questions
How is armodafinil different from modafinil?
It is the single, longer-lasting active component of modafinil, so it works in much the same way but can last longer in the body; the cautions are the same.
Does it affect my contraception?
Yes. Like modafinil, it makes hormonal contraception less reliable, so you should use additional or alternative methods during treatment and for a while afterwards.
What if I develop a skin rash?
Stop the medicine and seek urgent medical help, as it can rarely cause a serious skin or allergic reaction with spreading rash, blistering, peeling skin or facial swelling.
When should I take it?
It is usually taken once in the morning so it keeps you alert during the day without disturbing night-time sleep.
Is it safe in pregnancy?
It is not recommended in pregnancy; if you could become pregnant, discuss reliable contraception with your specialist.
Authoritative sources
- BNF
- NICE CKS
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