How is an Ativan (lorazepam) challenge done to rule out catatonia?

Lorazepam Challenge Test for Catatonia

The lorazepam challenge test involves administering 1-2 mg of lorazepam intravenously (or intramuscularly if IV access is unavailable), then observing for rapid improvement in catatonic symptoms within 5-15 minutes, with a positive response predicting successful treatment with continued lorazepam therapy. 1

Test Administration Protocol

Initial Dosing

• Administer 1-2 mg lorazepam IV push over 1-2 minutes as the initial challenge dose 1, 2
• If IV access is not available, give 2 mg lorazepam intramuscularly 3, 4
• The test should be performed after documenting baseline catatonic symptoms using a standardized rating scale (Bush-Francis Catatonia Rating Scale is the validated tool) 1, 3

Observation Period

• Observe the patient for 5-15 minutes after administration for improvement in motor signs, mutism, negativism, or other catatonic features 1, 2
• A positive response is defined as partial or complete resolution of catatonic symptoms within this timeframe 1
• Document specific improvements: ability to speak, follow commands, reduced rigidity, or resumption of voluntary movement 2, 3

Interpreting Results

Positive Challenge Test

• A positive response to the initial parenteral challenge predicts successful treatment with continued lorazepam therapy 1
• Patients who respond to the challenge typically achieve full remission with ongoing lorazepam treatment (oral or parenteral) over 1-5 days 1, 3
• 76% of patients with catatonia respond to a complete lorazepam trial when the challenge test is positive 1

Negative Challenge Test

• If no improvement occurs within 15-30 minutes, consider repeating with a second 2 mg dose 3, 4
• Failure to respond after two doses (total 4 mg) suggests the need for alternative treatment, specifically electroconvulsive therapy (ECT) 1, 3
• Patients failing lorazepam typically respond promptly to ECT 1

Treatment Protocol Following Positive Challenge

Continuation Therapy

• After a positive challenge, continue with lorazepam 2 mg IM every 4-8 hours or transition to oral dosing 3, 4
• Most patients (85.7%) achieve complete resolution of catatonia within 24 hours with continued treatment 3
• Some patients may require up to 5-7 days of treatment for full resolution 1, 3

Dosing Considerations

• Patients with less severe catatonia (lower Bush-Francis scores) are more likely to respond to a single dose 3
• Shorter duration of catatonic symptoms prior to treatment predicts better response to lorazepam 1
• High-dose lorazepam (up to 16-24 mg/day in divided doses) may be required for maintenance in some patients with recurrent catatonia 5

Critical Safety Precautions

Monitoring Requirements

• Monitor oxygen saturation and respiratory effort during and after administration, particularly when combining with other CNS depressants 6
• Be prepared to support ventilation, as rapid IV administration increases risk of apnea 6
• Respiratory depression is more likely in patients with underlying respiratory disease 6

Contraindications and Cautions

• Do not combine lorazepam with high-dose olanzapine due to reports of fatal outcomes from oversedation and respiratory depression 7
• Reduce doses by 20% or more in elderly patients due to reduced clearance 6
• Use lower doses (0.25-0.5 mg) in frail patients or those with COPD 7

Common Pitfalls to Avoid

• Do not underdose: Using less than 1-2 mg for the initial challenge reduces diagnostic sensitivity 1, 2
• Do not delay treatment: Catatonia is a medical emergency with potentially fatal outcomes if not recognized and treated promptly 2
• Do not abandon lorazepam prematurely: Some patients require up to one week of treatment, not just 1-2 days 1, 3
• Do not use benzodiazepines as monotherapy for underlying psychosis: While lorazepam treats catatonia, the underlying psychiatric condition (schizophrenia, mood disorder) requires appropriate antipsychotic or mood stabilizer treatment 3, 4