Painkillers frequently are prescribed to manage chronic pain that disrupts sleep. But a systematic review by a team of psychologists and medics found that research on the use of opioid drugs for aiding sleep is limited and that existing studies rarely consider side effects.

In fact, potential problems associated with the drugs may far outweigh the few reported benefits found, and it’s unclear whether patients understand this, lead author Nicole K. Y. Tang, Ph.D., of the University of Warwick, U.K. told McKnight’s.

“If we were to ask patients given opioid therapy to give an overall judgement about their sleep quality, they might report improvement but the effect is small and inconsistent,” she said.

Side effects associated with the use of opioids include excessive daytime sleepiness, decreased concentration and memory, nausea, and constipation, Dr. Tang said.

“The use of opioids is also linked to structural changes in sleep and an increased risk of disordered breathing during sleep,” she added. “However, we don’t know whether patients are discounting or simply not aware of these [effects]. This is something worthy of future investigation.”

Read further about this review.