Pharmacodynamics Differs with Age

Changes in sleep occur as individualsage, and management of insomniashould reflect those changes. Thereare age-related changes that affectpharmacodynamics and pharmacokinetics,altering drug metabolism. Drugclearance can be significantly reducedbecause of age-related declines inhepatic blood flow and glomerular filtration,complicating pharmacotherapy.Shorter-acting prescription hypnotics,which are compatible with age-relatedchanges in drug metabolism,are preferable pharmacotherapy forinsomnia in older patients.

This was one conclusion of a recentreview in Medscape Neurology &Neurosurgery (November 2005) onthe management of insomnia in elderlypatients. Furthermore, researchersnoted that sleep architecture isaltered as one ages. Seniors spendless time in slow-wave sleep andexperience less deep sleep duringthis stage.

The researchers also observed thatinsomnia in these patients often is overlooked.They reported that as many as40% of patients over the age of 60 mayexperience insomnia, frequent awakening,and disrupted sleep. The investigatorsbelieve that untreated insomnia,often associated with depressive symptoms,is clinically as important anddebilitating as untreated depression orundertreated hypertension.