Insomnia

Regulator of normal sleep

Circadian rhythm controlled by the suprachiasmatic nucleus (SCN) in the hypothalamus.

Stages of sleep

Non-REM (N1–N3) and REM; deep restorative sleep occurs in N3, dreaming in REM.

REM sleep features

Rapid eye movement, increased heart rate, vivid dreams, memory consolidation.

Definition of insomnia

Difficulty initiating or maintaining sleep or early awakening despite adequate opportunity, with daytime impairment.

Transient insomnia

Acute (short-term) insomnia

Chronic (persistent) insomnia

≥3 months, at least 3 nights per week.

Common comorbidities associated with insomnia

Depression, anxiety, asthma, GERD, chronic pain.

Medications that worsen insomnia

SSRIs (e.g., fluoxetine), corticosteroids, beta-agonists, stimulants.

Lifestyle factors that worsen insomnia

Stress, alcohol, caffeine, poor sleep hygiene.

Effect of alcohol on sleep

May shorten sleep onset but disrupts second half of sleep; increases awakenings.

Sleep hygiene: caffeine

Avoid caffeine at least 4–6 hours before bedtime.

Sleep hygiene: screen use

Avoid electronics 30–60 minutes before bed.

Best non-pharmacologic therapy

Cognitive Behavioral Therapy for Insomnia (CBT-I).

Dietary supplement for circadian rhythm

Melatonin.

Valerian root use

Mild sedative, limited evidence for insomnia.

First-generation antihistamines for sleep

Diphenhydramine and doxylamine.

Diphenhydramine dose for insomnia

25–50 mg at bedtime as needed, ≤10 days.

Elderly and diphenhydramine risk

Increased risk of confusion, dizziness, and falls.

Common side effects of first-generation antihistamines

Dry mouth, urinary retention, constipation, blurred vision, next-day drowsiness.

When to refer to a prescriber

Insomnia ≥3 weeks, secondary causes, pregnancy/lactation, elderly ≥65, children <12.

OTC antihistamine tolerance

Develops quickly; not for chronic use.

Best recommendation for alcohol use in insomnia

Avoid—may help you fall asleep but disrupts sleep later.

Appropriate non-drug advice

Regular sleep/wake schedule, limit naps, avoid heavy meals before bed.

Patient counseling for melatonin

Take 30–60 minutes before bedtime; avoid long-term daily use.

Mechanism of melatonin

Mimics natural hormone to regulate circadian rhythm.

Example of technology-assisted options

Calm, Sleep Cycle, Headspace, Somryst apps for relaxation and sleep tracking.

Signs of sleep hygiene improvement

Reduced sleep latency, fewer awakenings, improved daytime alertness.