Chapter 18: CNS Depressants & Sedative Medications

CNS Depressants & Sedative Medications begins by discussing the prevalence of sleep disorders like insomnia and the physiological nature of human sleep, which cycles through non-rapid eye movement and rapid eye movement stages. Before resorting to medication, the text advocates for nonpharmacologic sleep hygiene practices such as maintaining a consistent wake schedule and avoiding stimulants like caffeine or nicotine for six hours prior to rest. The pharmacology of sedative-hypnotics is detailed across several classes: barbiturates, which are now less frequently prescribed due to risks of dependency and severe respiratory depression; benzodiazepines such as alprazolam and lorazepam, which enhance the inhibitory effect of GABA to reduce neuronal excitability; and nonbenzodiazepines like zolpidem intended for short-term use. The chapter also introduces newer options including melatonin agonists and orexin antagonists that regulate circadian rhythms or block wakefulness without significantly altering sleep architecture. Special emphasis is placed on the risks associated with these drugs, such as residual "hangover" effects, REM rebound, and complex sleep-related behaviors. The second half of the chapter transitions to anesthesiology, distinguishing between general anesthetics that induce a total loss of consciousness and local anesthetics that provide regional pain relief. It describes the four stages of general anesthesia and the concept of balanced anesthesia, which utilizes a combination of agents to minimize side effects and accelerate recovery. Various delivery methods are explored, including inhalation gases, intravenous agents like propofol, and regional techniques such as spinal, epidural, and nerve blocks. Throughout the discussion, the role of the nurse is highlighted, particularly in monitoring vital signs, assessing for adverse reactions in older adults, and providing patient education to ensure safe therapeutic outcomes.