The most appropriate next step in the management of this patient is to recommend sleep restriction counseling. Insomnia is the inability to initiate or maintain adequate sleep, and it may be acute or chronic. This patient's symptoms have been persistent. The initial step in the evaluation of a patient with insomnia is a thorough history and physical examination. When there is no evidence of stimulant use, sleep-disordered breathing, restless legs syndrome, hypothyroidism, depression, or other chronic medical problems that might impair sleep (COPD, heart failure, osteoarthritis), initial treatment should focus on sleep hygiene and, if unsuccessful, a trial of sleep restriction. Sleep restriction limits and then gradually increases the time in bed for sleep. It utilizes the concept of sleep efficiency (total sleep time divided by total time in bed). The patient calculates the average total sleep time per night, and then he or she spends that amount of time in bed, keeping the arising time constant. For example, if a patient determines that his total time asleep is 6 hours per night and he sets his waking time as 6:00 AM, his bedtime would be 12:00 AM, even if he is feels tired before that time. The time in bed gradually increases by 15 minutes as long as the sleep efficiency is greater than 85%. This patient has implemented good sleep hygiene techniques (avoiding daytime napping, limiting caffeine and alcohol, keeping the bedroom quiet and dark, and avoiding the use of electronic devices in bed) without achieving significant benefit. Sleep restriction should be initiated next in this patient.

Diphenhydramine, an over-the-counter sedating antihistamine, is commonly used to treat insomnia. It induces sedation; however, its resultant anticholinergic side effects, daytime somnolence, and cognitive impairment limit its overall safety and benefit. In most patients, nonpharmacologic interventions are preferred for treatment of insomnia, particularly chronic insomnia. If pharmacologic therapy is needed, diphenhydramine is not generally recommended due to its significant side effect profile.

In general, a regular exercise regimen can help improve sleep. However, vigorous exercise before bedtime should be avoided because it may impair the ability to fall asleep.

Zolpidem, a short-acting nonbenzodiazepine selective γ-aminobutyric acid (GABA) agonist, is prescribed for the treatment of short-term or situational insomnia. It may have fewer side effects than older prescription sleep aids, but cognitive impairment, rebound insomnia, dependency, sedation, and, rarely, sleep driving, eating, and walking have been reported. In this patient, sleep restriction should be tried before pharmacologic therapy.