BALTIMORE—Nocturnal awakenings can be treated using prophylactic nighttime dosing, as-needed (PRN) treatment, or sleep-maintenance (ie, sleep-enhancing) medications, although several problems are associated with these options, according to James K. Walsh, PhD. If a drug is short-acting, it will suppress nocturnal awakenings for a suboptimal time, he pointed out. On the other hand, if a drug is too long-acting, a patient may experience adverse effects after awakening. Dr. Walsh, who is the Executive Director of the Sleep Medicine and Research Center, St. Luke’s Hospital, St. Louis, and President of the National Sleep Foundation, addressed the 22nd Annual Meeting of the Associated Professional Sleep Societies.
Research on Nocturnal Awakenings Is Insufficient
Although the frequency of nocturnal awakenings is the most specific sleep-maintenance measure, overall research regarding nocturnal awakenings is insufficient, noted Dr. Walsh. A couple of key methodologic reasons account for this, he said, including the lack of a consensus definition and no clear understanding of the clinical relevance of nocturnal awakenings or how to measure the number of nocturnal awakenings (whether by polysomnography or self-report).
Typically, self-reports of nocturnal awakenings have correlated poorly with polysomnography measurement. In addition, polysomnography measurements of nocturnal awakenings do not differentiate patients with primary insomnia from healthy subjects. Although a large number of primary insomnia studies have been conducted, fewer than 20% of all patients with insomnia are likely represented, said Dr. Walsh.
Prophylactic Treatment and PRN Therapy
For patients who have experienced chronic nocturnal awakenings, medication taken at the beginning of the night may be the best option, recommended Dr. Walsh. However, prophylactic treatment may not be the best choice for persons who have less predictable nocturnal awakening patterns or for those who experience nocturnal awakenings and difficulty returning to sleep only one or two nights per week.
Other disadvantages of prophylactic treatment include the possibility of increased overall drug intake and duration of action that may interfere with the following day’s wakefulness and functioning.
Another treatment option for patients who awaken and have difficulty falling back to sleep is PRN therapy. However, PRN treatment can also present difficulties, noted Dr. Walsh. If a person awakens after two to three hours of sleep and takes an insomnia drug—most medications have a 60- to 90-minute peak plasma level—this would not allow the person to return to sleep within 20 to 30 minutes. Dr. Walsh asserted that there is a need for drugs that are absorbed more quickly than current medications, with duration of action that is appropriate for use in the middle of the night. Zaleplon is the only drug approved for insomnia that can be taken during the middle of night, as long as the person plans to sleep for at least another four to five hours, he said.
Transmucosal zolpidem, which is in development, may fit this need, commented Dr. Walsh. Because it is a lozenge that dissolves under the tongue in two to three minutes, it has a peak plasma time that is about half that of other insomnia medications. According to Dr. Walsh, it has been effective at improving rates of returning to sleep and increasing total sleep time after people have returned to sleep.
Sleep-Enhancing Medications
Sleep-enhancing drugs might reduce the possibility for waking and arousal and therefore lessen the likelihood of nocturnal awakenings. Although total sleep time increased by 20 minutes in one study involving use of tiagabine, the number of awakenings declined. For some people, sleep maintenance with fewer awakenings might be as important, or more important, as total sleep time. Reducing arousals and consolidating sleep has potential benefits for the overall insomnia profile, Dr. Walsh concluded.
—Mary Brady Service