However, they also caused headaches, nausea and a rise in blood pressure in a substantial number of people."
London, Aug 13 - The drugs that shift workers are taking to help them stay awake or get to sleep are not of much benefit and they may do more harm than good, says a review of available research.
For lots of people who do shift work, it would be really useful if they could take a pill that would help them go to sleep or stay awake at the right time, said lead author of the review, Juha Liira, who is based at the Finnish Institute of Occupational Health in Helsinki, Finland.
But from what we have seen in our review, there is not good evidence that these drugs can be considered for more than temporary use and some may have quite serious side effects, Liira added.
The review included 15 trials involving a total of 718 people. In nine trials, the over-the-counter hormone drug melatonin helped shift workers sleep for around 24 minutes longer during the night or day, compared to placebos.
However, it did not help them get to sleep any quicker.
Data from only one trial of the hypnotic drug zoplicone was available. The drug was no more effective than placebos for helping shift workers sleep during the day.
Modafinil and armodafinil, used by shift workers in one and two trials respectively, increased alertness and reduced sleepiness.
However, they also caused headaches, nausea and a rise in blood pressure in a substantial number of people.
The study appeared in Cochrane Reviews.