Home » Other Drugs » Modafinil
Brand Name: Modalert, Moderateafinil, Modiodal, Modapro, Provigil
Generic Name: Modafinil
How does Modafinil work?
These tablets contain the active ingredient modafinil, which is a type of medicine known as a CNS stimulant. It works by stimulating activity within the central nervous system, ie the brain and spinal cord.
Modafinil increases wakefulness and daytime alertness in people who experience excessive sleepiness during the day, either due to narcolepsy, or due to a syndrome called obstructive sleep apnoea. It can also be used to improve wakefulness and alertness in people who suffer moderate to severe sleep disorders as a result of chronic shift work. However, the medicine should not be used as a replacement for sleep and you should talk to your doctor about ways to try and maintain good sleep patterns.
The way in which modafinil improves wakefulness is not yet fully understood, but it is believed to have an effect on specific parts of the brain responsible for keeping us awake.
Modafinil's mode of action appears to be different to other CNS stimulants, such as the amphetamine group of medicines that are also sometimes used to promote wakefulness. This difference is believed to reduce modafinil's potential for abuse and dependence, though there may still be a risk of this if the medicine is used long-term.
What is it used for?
• Excessive daytime sleepiness due to the sleep disorder narcolepsy.
. Excessive daytime sleepiness due to obstructive sleep apnoea/hypopnoea syndrome.
. Excessive sleepiness due to moderate to severe sleep disorders associated with chronic shift work.
. This medicine may cause dizziness and blurred vision. If affected, caution is required when driving or operating machinery.
. The safety of this medicine during pregnancy has not been established. Because it may be harmful to a developing baby, women who could get pregnant should use a reliable contraceptive method to prevent pregnancy while using this medicine. Contraception should be continued for two months after stopping treatment. There is more information about the effect of this medicine on contraceptive pills and patches at the end of this factsheet. It is important to discuss contraceptive methods with your doctor before you start taking this medicine.
. If you get a rash during treatment with this medicine you should stop taking it and consult your doctor.
. Psychiatric side effects, including depression and suicidal thoughts, have been reported in people taking this medicine. If you experience any distressing thoughts or feelings, particularly about suicide or harming yourself, at any point during treatment with this medicine it is important to stop taking it and talk to your doctor.
. Dependence on this medicine may occur if it used for long periods of time.
Use with caution in
. Elderly people.
. Heart disease.
. High blood pressure (hypertension) (blood pressure and heart rate should be monitored).
. Kidney failure.
. Liver failure.
. Severe anxiety.
. History of psychosis, depression or mania.
. History of drug, alcohol or substance abuse.
Not to be used in
. Irregular heart beats (arrhythmias).
. Uncontrolled moderate to severe high blood pressure (hypertension).
. History of enlargement of a chamber of the heart (left ventricular hypertrophy or cor pulmonale).
. People with a floppy heart valve (prolapsed mitral valve) who have experienced the 'mitral valve prolapse syndrome' when taking CNS stimulants (ask your doctor about this if you have heart valve problems).
. Rare hereditary disorders of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption (Provigil tablets conatin lactose).
. There is insufficient information regarding the safety and efficacy of this medicine in children. It is not recommended for children.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
. The safety of this medicine during pregnancy has not been established. Because it may be harmful to a developing baby, it should not be used during pregnancy. Women who could get pregnant should use a reliable contraceptive method to prevent pregnancy while using this medicine. Contraception should be continued for two months after stopping treatment. There is more information about the effect of this medicine on contraceptive pills and patches at the end of this factsheet. You should discuss contraceptive methods with your doctor before starting treatment.
. It is not known if this medicine passes into breast milk. It should not be used during breastfeeding. Seek medical advice from your doctor.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.
. Blurred vision.
. Dry mouth.
. Loss of appetite.
. Disturbances of the gut such as diarrhoea, constipation, nausea, vomiting or abdominal pain.
. Weakness or loss of strength (asthenia).
. Difficulty sleeping (insomnia).
. Anxiety and agitation.
. Pins and needles sensations (paraesthesia).
. Alteration in results of liver function tests.
. Unstable moods (emotional lability).
. Decreased sex drive.
. Chest pain.
. Changes in your heart rate or blood pressure.
. Skin reactions such as rash or itching (see warning above).
. Psychiatric reactions (see warning above).
The side effects listed above may not include all of the side effects reported by the drug's manufacturer.For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.
This medicine may reduce the effectiveness of oral contraceptive pills and patches because it may speed up the breakdown (metabolism) of the hormones in the body. For this reason, women who are using hormonal contraceptives should use an additional method of contraception, such as condoms, to help prevent pregnancy. Alternatively, it may be more appropriate to use a different method of contraception altogether, particularly for women using this medicine long-term. Whichever method is used, effective contraception should be continued for two months after stopping treatment with modafinil. It is important for women to discuss contraception with their doctor before they start treatment with this medicine.
Antiepileptic medicines such as carbamazepine and phenobarbital may reduce the blood level of this medicine.
Modafinil may increase the blood level of the antiepileptic medicine phenytoin, and people taking both these medicines should have their phenytoin levels monitored.
Modafinil may decrease the blood level of the following medicines:
. calcium channel blockers
. protease inhibitors for HIV infection
. statins for lowering cholesterol
Modafinil may increase the blood levels of antidepressant medicines in a particular group of people known as ‘poor metabolisers’. These people lack a particular enzyme (CYP2D6) that breaks down medicines in the body, and so may need a lower dose of antidepressant if also taking modafinil.
The manufacturer of this medicine recommends that people who are taking the anti-blood-clotting medicine (anticoagulant) warfarin should have their blood clotting time monitored regularly during the first two months of treatment with this medicine and after any dose changes.