What is the drug of choice for an acute anxiety attack?

Drug of Choice for Acute Anxiety Attack

For an acute anxiety attack, benzodiazepines—specifically lorazepam (2 mg) or midazolam—are the drugs of choice due to their rapid onset of action and high efficacy in quickly reducing acute anxiety symptoms. 1

Benzodiazepines as First-Line Treatment

Lorazepam is the preferred benzodiazepine for acute anxiety attacks because it offers:

• Fast onset of action 1
• Rapid and complete absorption 1
• No active metabolites 1
• Reliable intramuscular absorption if parenteral administration is needed 1

Midazolam may be considered when even more rapid onset is required, though it has a shorter duration of action than lorazepam 1. The typical starting dose for lorazepam is 2 mg, which has been validated in multiple controlled trials 1.

Mechanism and Efficacy

Benzodiazepines work by binding to presynaptic GABA receptors, enhancing the primary CNS inhibitory neurotransmitter and decreasing neuronal excitability 1. This mechanism provides immediate anxiolytic effects, making them ideal for acute presentations 2.

Multiple class II studies demonstrate that benzodiazepines are at least as effective as antipsychotics (such as haloperidol 5 mg) for acute agitation and anxiety, with the advantage of faster symptom relief 1.

Alternative Agents for Specific Situations

Alprazolam (0.25-0.5 mg orally) can be used for anticipatory anxiety when the patient is cooperative and can take oral medication 1, 3. However, alprazolam is not recommended for long-term use in the UK due to dependence concerns 2.

Diazepam is effective for single-dose or intermittent use in acute stress reactions and episodic anxiety 2. However, it has erratic intramuscular absorption and a longer half-life, making it less ideal than lorazepam for acute presentations 1.

Important Caveats and Contraindications

Avoid benzodiazepines in elderly patients when possible due to increased risk of:

• Cognitive impairment 4
• Falls 4
• Paradoxical agitation 4

Do not use benzodiazepines as monotherapy for long-term anxiety management beyond 2-4 weeks maximum due to risks of tolerance, dependence, and withdrawal 2, 5. For ongoing anxiety disorders, transition to SSRIs or SNRIs after the acute episode resolves 1, 6, 5.

Screen for substance use disorders before prescribing, as benzodiazepines carry significant abuse potential 2, 7.

When Antipsychotics May Be Preferred

If the acute anxiety is accompanied by psychosis, agitation, or violent behavior, consider:

• Haloperidol 5 mg IM 1
• Droperidol for more rapid sedation (though FDA black box warning exists) 1
• Combination of lorazepam 2 mg plus haloperidol 5 mg for severe agitation 1

The combination approach may produce more rapid sedation than monotherapy in severely agitated patients 1.

Practical Algorithm

1. Assess severity and presentation: Pure anxiety vs. anxiety with agitation/psychosis
2. For pure acute anxiety: Lorazepam 2 mg PO/IM as first-line 1
3. For very rapid onset needed: Consider midazolam 1
4. For anxiety with severe agitation: Lorazepam 2 mg + haloperidol 5 mg 1
5. Reassess after 30-60 minutes and redose if needed 1
6. Plan transition to long-term management with SSRIs/SNRIs if chronic anxiety disorder is present 1, 5