A 32-year-old woman comes to the office due to long-standing anxiety. She reports being excessively worried about everyday events and constantly feeling tense and unable to relax. The patient is diagnosed with generalized anxiety disorder and treated with a selective serotonin reuptake inhibitor. She returns to the office for a 2-month follow-up and reports that her overall anxiety has improved, but she continues to have periods of increased anxiety before bedtime that keep her awake at night. The patient works as a 911 emergency dispatch operator and would be willing to add a medication at bedtime but needs to be "clearheaded" for work. Which of the following medications is most appropriate for this patient's condition?
Duration of action of common benzodiazepines | |
Short | Triazolam, midazolam |
Intermediate | Oxazepam, alprazolam, lorazepam, clonazepam |
Long | Diazepam, chlordiazepoxide, flurazepam |
Although antidepressants (selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors) are first-line medications for generalized anxiety disorder (GAD), benzodiazepines are also effective and can be used as adjuncts in partial responders. Benzodiazepines are typically divided into categories based on their half-lives (eg, short, intermediate, long).
In selecting a benzodiazepine for this patient, it is important to minimize undesirable side effects (eg, sedation, fatigue, impaired judgment), especially given the nature of her work. This is best achieved by prescribing a short- or intermediate-acting benzodiazepine such as lorazepam (average half-life of 12 hours) at bedtime, which will lower her anxiety, help her fall asleep, and be less likely to impair her daytime cognitive performance. Benzodiazepines with longer elimination half-lives are associated with prolonged side effects and should be avoided when trying to minimize side effects.
(Choices A, B, and C) Chlordiazepoxide, diazepam, and flurazepam have longer durations of action compared to lorazepam. These agents are more likely to result in prolonged side effects (eg, daytime sedation, impaired judgment), which are undesirable considering this patient's job.
(Choice E) Quetiapine is a second-generation antipsychotic that is associated with numerous potentially severe side effects, including sedation, weight gain, and metabolic syndrome. It is not recommend for treating insomnia in patients without psychosis.
Educational objective:
When benzodiazepines are used in the treatment of anxiety, drug selection should consider the medication's duration of action. Short- to intermediate-acting benzodiazepines (eg, lorazepam) are preferred in situations in which prolonged side effects of sedation and cognitive impairment must be minimized.