Antidepressants may extend need for hypnotics.

BARCELONA -- Antidepressant use seems to potentiate the need for concomitant hypnotic medications for extended periods, despite national recommendations that the sleeping aids be prescribed for no more than 4 consecutive weeks, a large study in the United Kingdom has determined.

The finding suggests that, in the U.K.,

prescribing guidelines for hypnotics for depressed patients need an overhaul, according to John Donoghue, a research pharmacist at Liverpool (England) John Moores University. "In the U.K., the British National Formulary states that hypnotics are appropriate for the management of severe insomnia only, for a maximum of 2-4 weeks. Guidance from the National Institute for Health and Clinical Excellence makes similar recommendations," he wrote in a poster presented at the annual congress of the European College of Neuropsychopharmacology.

"However, no guideline takes into account the need to manage disturbed sleep in depression--a very common symptom which is difficult to manage."

Mr. Donoghue and his colleague, Dr. Malcolm H. Lader of King's College London, examined 10 years' of antidepressant and hypnotic prescribing records contained in the DIN-LINK Database, which contains prescription records for more

than 775,000 patients. Data were collected for years 1996-2005 for all new patients older than 18 years who received a prescription for a hypnotic. None of these patients had received any hypnotic or anxiolytic prescription in the 12 months before their new prescription. The researchers followed the medication records of each patient for 1 year after their hypnotic prescription was issued.

The proportion of patients receiving a hypnotic who had a depression diagnosis increased over much of the study period, from 62% in 1996 to a high of 75% in 1999. By 2005, the percentage had slipped somewhat, to 68%. Over the study period, the proportion of patients receiving a selective serotonin reuptake inhibitor increased (from 10% to 23%), while the proportion of those receiving a tricyclic antidepressant decreased (from 48% to 20%).

For each year of the study, the prescription of an antidepressant was associated with an increased length of hypnotic treatment. Most patients who were not taking antidepressants took hypnotics for 4 weeks or less (60%-70%). However, few of those taking a concomitant antidepressant stayed on their hypnotic medication for this recommended brief period (28%-38%).

Each year, less than 10% of those not taking antidepressants took hypnotics for more than 3 months, and less than 5% took hypnotics for a year. However, 20%-3G% of patients taking antidepressants used hypnotic drugs for more than 3 months, and 7%-12% took them for more than a year. The trend was even more obvious for those who took tricyclic antidepressants. Depending on the study year, 32%-48% of these patients took hypnotic drugs for more than 3 months, and 15%-30% took them for 1 year.

"Many patients without a diagnosis of depression were prescribed antidepressants as well, possibly for the treatment of anxiety disorders," the investigators noted. "Among these, the proportion who received a hypnotic for more than 3 months was 28%--nearly three times higher than those not prescribed an antidepressant."

This finding suggests that commonly prescribed antidepressants might exacerbate sleep problems in nondepressed patients, they added.

The study was supported by an unrestricted educational grant from Servier Laboratories Inc., a European pharmaceutical company that is developing a novel antidepressant, agomelatine, for marketing in the United States. The drug is a melatonin receptor agonist with additional 5-HT2c antagonism properties, according to the company Web site.

BY MICHELE G. SULLIVAN

Mid-Atlantic Bureau