A sharp rise in the use of sleeping pills saw NHS spending on the drugs reach nearly £50 million last year, new figures reveal.
Some 15.3 million prescriptions were handed out in 2010/11, compared with 14.5 million in 2007/08, according to NHS figures obtained by the Co-operative Pharmacy.
A Freedom of Information request revealed health trusts spent £49.2million on the drugs in 2010/11, up from £42 million three years previously - an increase of more than 17%.
The highest number of prescriptions for sleeping pills were dispensed in the North West, which spent more than £8.5 million on almost 2.5 million sleeping medication items.
Zoplicone was given to more than 5.2 million patients nationally, making it the most popular sleeping tablet.
Around a third of people in the UK are thought to have bouts of insomnia, which can become a debilitating problem for some. However, health chiefs have voiced concerns that frequent use of sleeping pills can lead to "psychological dependency".
Mandeep Mudhar, NHS business director at the Co-operative Pharmacy, said: "Our research shows that millions of people suffer from a lack of sleep each year and are seeking medical help for the problem. While usage has risen steadily, the costs to the NHS have risen disproportionately, with costs going up at a greater rate."
Research published in February found sleeping pills commonly prescribed in the UK may increase the risk of death more than four-fold.
A wide range of drugs was analysed for the study of more than 10,500 people taking the drugs. They included drugs used in the UK, such as benzodiazepines (including temazepam and diazepam), non-benzodiazepines (including zolpidem, zopiclone and zaleplon), barbiturates and sedative antihistamines.
The research, from experts at the Jackson Hole Centre for Preventive Medicine in Wyoming and the Scripps Clinic Viterbi Family Sleep Centre in California, found that people prescribed sleeping pills were 4.6 times more likely to die during a 2.5-year period compared to those not on the drugs.