Modafinil is a new pharmacological compound with a unique effect on the brain that is not fully understood. It has been licensed in the UK as a treatment for narcolepsy, a rare disorder marked by an intense and overwhelming need to sleep that can strike at any time. Surveys show a third of people get less sleep than they need, which is blamed on the invention of electricity. By extending the waking day, modafinil could provide the pharmaceutical equivalent of the electric light bulb.
Unlike amphetamines, which stimulate the nervous system, modafinil appears to target the hypothalamus, the area of the brain thought to be responsible for wakefulness. Tests in normal volunteers have shown it boosts cognitive performance, especially memory, and reaction times in the sleep-deprived.
Its main advantage over amphetamines is that it does not produce the euphoria associated with those drugs and is thought not to be addictive. Yet tests on normal volunteers show it can keep people going through the night without causing rebound depression or sleepiness.
Dr Colin Markland, medical director of Cephalon UK, which is marketing the drug, to be called Provigil, in Britain, said there were no plans to explore its potential as an alertness pill.
"All our activities have been in the area of narcolepsy. If we wanted to seek another indication for the drug we would have to go back and conduct other studies." Military organisations in France, where the drug was first licensed in 1994, the US and Britain are understood to have shown interest. There would be an obvious military advantage in a pill that could help armies fight through the day and march through the night.
Dr Markland that in the four years the drug had been available in France there had been no evidence of abuse but this would be monitored in Britain. It is available on prescription only and costs pounds 60 for 30 tablets of 100g.
The normal dose for treating narcolepsy would be 200g to 400g a day, costing up to almost pounds 3,000 a year. If proved safe and effective, modafinil might become a treatment for jet-lag or for disrupted sleep caused by shift work. But by far its biggest potential market could be in the treatment of insomnia - by preventing sleep during the day and thus promoting it at night.