SEATTLE -- Duration and onset of action are the most important considerations in choosing a benzodiazepine receptor agonist to treat acute insomnia, Dr. Vishesh Kapur said at a meeting on drug therapy sponsored by the University of Washington.
"A rational approach to using these [benzodiazepines] is to fit the agent to the complaint," said Dr. Kapur, medical director of the sleep disorders clinic at Harborview Medical Center in Seattle.
The short-acting benzodiazepines triazolam, zolpidem, and zaleplon are particularly useful for sleep-onset problems, but they often do little to prolong sleep time or prevent repeated wakings during the night.
"Zaleplon in particular is a very short-acting agent and in a lot of studies has been shown not to increase total sleep time at all," he said.
These agents have less respiratory depressant effects than their longer-acting counterparts, he added.
If a patient's chief complaint is sleep maintenance, use an intermediate-acting agent such as lorazepam, estazolam, or temazepam. These agents have some effect on sleep onset but a larger effect on sleep maintenance.
Start the patient on the lowest dose possible (such as 0.5 mg for lorazepam) and increase the dose on a nightly basis until the desired effect is achieved. Maintain the medication for 4-5 days and then reevaluate the patient.
The "hangover effect" from intermediate-acting benzodiazepines is marked at higher doses, noted Dr. Kapur, also of the department of medicine at the University of Washington in Seattle.
The long-acting benzodiazepines clonazepam, flurazepam, and quazepam enhance sleep maintenance, but most patients experience a hangover effect that can last well into the following day, he said. Clonazepam is the most commonly prescribed of these agents because it is also useful for restless leg syndrome and periodic limb movements during sleep.
Long-acting benzodiazepines should be avoided in the elderly because of the increased risk for falls and hip fractures.
In general, benzodiazepine therapy for acute insomnia should be limited to 2 weeks, he added.
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