Chapter 6: Sedative-Hypnotic and Antianxiety Drugs

INTRODUCTION

Sedative-hypnotic and antianxiety drugs are among the most commonly used drugs worldwide. These agents exert a calming effect and help relax the patient.¹ At higher doses, the same drug can produce drowsiness and initiate a relatively normal state of sleep (hypnosis). At still higher doses, some sedative-hypnotics (especially barbiturates) will eventually bring on a state of general anesthesia. Because of their general central nervous system (CNS)–depressant effects, some sedative-hypnotic drugs are also used for other functions, such as treating epilepsy or producing muscle relaxation.

While producing sedation, many drugs will also decrease the level of anxiety in a patient. Of course, these anxiolytic properties often cause a decrease in the level of alertness in the individual. However, certain agents are available that can reduce anxiety without an overt sedative effect. Hence, these agents are classified as antianxiety drugs because they produce less sedation than their sedative-hypnotic counterparts. However, this distinction is relative because most antianxiety drugs produce some level of sedation, especially at higher doses.

It is estimated that insomnia affects between 10 to 15 percent of the general population, and pharmacological management can be helpful in promoting normal sleep.² Moreover, people who are ill or who have recently been relocated to a new environment (hospital, nursing home) will often have difficulty sleeping and might need some form of sedative-hypnotic agent.^3,4 A person who sustains an injury or illness may have some apprehension concerning his or her welfare.^2,5 If necessary, this apprehension can be controlled to some extent by using antianxiety drugs during the course of rehabilitation. Besides medications, there are many nonpharmacological interventions that may help control anxiety and/or promote better sleep hygiene.

As a therapist, you will encounter many patients who are taking sedative-hypnotic and antianxiety agents. It is important that you understand the basic pharmacology of these agents and their adverse effects. Many sedative-hypnotic drugs are not recommended as sleeping aids due to their risk of increasing confusion, delirium, falls, and dependency.⁶

SEDATIVE-HYPNOTIC DRUGS

Sedative-hypnotics fall into two general categories: benzodiazepines and nonbenzodiazepines (Table 6-1). Selective agents are used to promote sleep, especially in relatively acute or short-term situations where sleep has been disturbed by illness, injury, or other factors. We will address the benzodiazepines first, followed by a description of the nonbenzodiazepine hypnotics.