Anxiolytics
Key Points
- Benzodiazepines: First-line for acute anxiety — Schedule IV; CNS depressants; reversal agent is flumazenil
- Benzodiazepines enhance GABA activity → CNS depression; risk of tolerance, dependence, and withdrawal
- NEVER stop benzodiazepines abruptly — taper to prevent withdrawal seizures, rebound anxiety
- Benzodiazepines + opioids: Boxed Warning — risk of profound sedation, respiratory depression, coma, death
- Buspirone: Non-addictive alternative; takes 2–4 weeks for effect; no sedation or addiction risk
- Buspirone is not PRN and should not be combined with MAOIs; serotonergic combinations can trigger serotonin toxicity
- Benzodiazepines are second-line long-term (SSRIs/SNRIs are first-line for chronic anxiety disorders)
Drug Class Overview
Anxiolytics are medications used to reduce pathological anxiety, which is characterized by symptoms disproportionate to events, sustained over time, impairing function, and causing significant distress. Clinical manifestations involve sympathetic nervous system activation: muscle tension, tachycardia, diaphoresis, dyspnea, trembling, difficulty concentrating, and dizziness.
Anxiety disorders requiring treatment include generalized anxiety disorder (GAD), panic disorder, social anxiety disorder, PTSD, and OCD. The pathophysiology involves excess excitatory neurotransmitters (norepinephrine) or deficiency of inhibitory neurotransmitters (GABA).
Benzodiazepines — First-Line Acute Anxiolytics
Mechanism: Bind to GABA-A receptors in the limbic system and reticular activating system (RAS) → enhance GABA’s inhibitory effect → decreased neuronal excitability → anxiolysis and sedation. At higher doses, produce sleep (sedative-hypnotic effect).
Schedule: DEA Schedule IV controlled substance — significant abuse and physical dependence potential.
Common Agents:
| Drug | Key Notes |
|---|---|
| Lorazepam (Ativan) | First choice benzodiazepine for acute anxiety and agitation; IV use induces procedural amnesia |
| Alprazolam (Xanax) | Preferred for rapid onset of action; also used for panic disorder |
| Diazepam (Valium) | Long half-life; also used for alcohol withdrawal and seizures; older adults more sensitive to effects |
| Clonazepam (Klonopin) | Monitor suicidal ideation, liver function, CBC |
| Midazolam (Versed) | Short-acting; IV for procedural sedation and pediatric anesthesia; available as flavored syrup |
| Temazepam (Restoril) | Drug of choice for older adults and patients with liver disease (for sleep) |
Additional Indications: Alcohol withdrawal syndrome, acute seizure management, procedural sedation, muscle relaxation.
Adverse Effects:
- CNS depression: Drowsiness, sedation, cognitive impairment, confusion
- Anterograde amnesia: Inability to form new memories (especially IV midazolam)
- Respiratory depression: Especially when combined with opioids or alcohol
- Paradoxical reactions: Paradoxical excitement or aggression (especially in children and older adults)
- Falls: Excessive sedation increases fall risk
- Physical dependence with prolonged use
Reversal Agent: Flumazenil — specific benzodiazepine receptor antagonist; reverses sedation and respiratory depression; monitor for re-sedation as flumazenil has shorter half-life than most benzodiazepines.
Benzodiazepines + Opioids — Boxed Warning
Concomitant use of benzodiazepines with opioids can result in profound sedation, respiratory depression, coma, or death. Reserve combined use for patients for whom alternative treatments are inadequate. Limit dosages and duration to minimum required.
Tapering Protocol: Benzodiazepines must be tapered slowly on discontinuation to prevent withdrawal syndrome (anxiety rebound, insomnia, tremors, diaphoresis, seizures). NEVER abrupt discontinuation.
Buspirone (BuSpar) — Non-Addictive Alternative
Mechanism: Partial agonist at serotonin 5-HT1A receptors; does not bind to GABA receptors; no sedation or addiction potential.
Advantage: Unlike benzodiazepines, buspirone does not cause sedation, cognitive impairment, or physical dependence. It does NOT potentiate alcohol or opioids.
Onset: 2–4 weeks for therapeutic effect — not appropriate for acute anxiety management.
Indications: Generalized anxiety disorder (first-line for long-term management in patients where benzodiazepines are inappropriate).
Contraindications/Interactions: Do not use concurrently with monoamine oxidase inhibitors (MAOIs). Combination with MAOIs, SSRIs, or SNRIs can increase serotonin-syndrome risk.
Adverse Effects: Dizziness, nausea, headache, nervousness (usually mild and transient).
SSRIs and SNRIs — First-Line for Chronic Anxiety
For most anxiety disorders, SSRIs (fluoxetine, sertraline, escitalopram) and SNRIs (venlafaxine, duloxetine) are first-line long-term pharmacotherapy. See antidepressants for details.
Benzodiazepines are typically bridged for the 2–6 weeks while SSRIs/SNRIs reach therapeutic effect, then tapered and discontinued.
Nursing Assessment
Before Administration:
- Assess baseline anxiety level and current triggers; mental status and orientation
- Review history of substance use disorder (contraindication or extreme caution for benzodiazepines)
- Check current medications for interactions — especially other CNS depressants and opioids
- Fall risk assessment — implement fall precautions for all benzodiazepine patients
Ongoing Monitoring:
- Level of consciousness and respiratory rate (CNS depression, respiratory depression risk)
- Mood: Watch for paradoxical reactions (agitation, aggression, euphoria)
- Assess for dependence symptoms with long-term use
- Monitor suicidal ideation (clonazepam specific)
- In children and older adults, watch closely for exaggerated sedation, respiratory depression, or paradoxical agitation/hallucinations
Patient Education:
- Do NOT stop benzodiazepines abruptly — always taper per provider guidance
- Avoid alcohol and other CNS depressants — risk of respiratory depression
- Delay driving or hazardous tasks for 24–48 hours after benzodiazepine doses (especially lorazepam) or until sedation resolves
- In inpatient settings, request assistance before ambulation because benzodiazepines increase fall risk
- Buspirone: requires consistent daily use 2–4 weeks before effect; do not take PRN
- Report increased anxiety, agitation, or thoughts of self-harm immediately
Related Concepts
- antidepressants — SSRIs/SNRIs as first-line chronic anxiety treatment
- sedative-hypnotics — Benzodiazepines also used as sleep aids
- substance-use-disorders — Benzodiazepine dependence and withdrawal management
- psychopharmacology — Broader overview of psychiatric medications
- self-harm-and-suicide — Suicidal ideation risk with clonazepam; anxiety and suicide risk
- psychotropic-medications — Overview of all classes of psychiatric medications
Self-Check
- A patient on long-term lorazepam therapy requests to stop the medication. What is the appropriate nursing response regarding discontinuation?
- What is the reversal agent for benzodiazepine toxicity, and what monitoring is required after administration?
- A patient asks why the nurse cannot prescribe buspirone for immediate relief of her anxiety attack. How would you explain buspirone’s onset of action?