Ketamine and Midazolam Infusions for CRPS: Feasibility Study

Feasibility Study Comparing a Ketamine and Midazolam Infusion to a Midazolam-Only Infusion for Complex Regional Pain Syndrome

This study will assess the feasibility of administering ketamine plus midazolam or midazolam alone, when infused over 5 days in an outpatient setting, to adults with complex regional pain syndrome (CRPS).

Subanesthetic ketamine infusions are a potentially impactful treatment for chronic refractory pain, but the acute psychoactive effects of ketamine complicate successful masking in randomized trials. Multi-day ketamine infusions have produced long-lasting, but not permanent, remission of symptoms in complex regional pain syndrome (CRPS), a chronic and often debilitating neuropathic pain condition that can affect one or more limbs. In this feasibility study, 4 adults with CRPS will be randomized to receive either ketamine and midazolam or midazolam-only, infused over 5 days in an outpatient setting. The objectives of this feasibility study are:

1. Assess whether the recruitment and retention rate observed in this feasibility study can support a larger clinical trial.
2. Evaluate whether participants can adhere to study procedures.
3. Determine whether midazolam, when given alone as an intravenous (IV) infusion, can be used as an active placebo that is well-tolerated, practical, and believable compared to a ketamine plus midazolam infusion.
4. Gather preliminary data on clinically-relevant outcomes for CRPS.

• Age 18 to 65 years
• Meets the International Association for the Study of Pain (IASP) diagnostic criteria for complex regional pain syndrome (CRPS)
• Primary complaint of CRPS-attributable pain for ≥3 months
• Average pain intensity of ≥3/10 over the last month
• Can read and comprehend English-language questionnaires
• Can receive text messages by phone
• Can identify a responsible adult who can provide transportation to and from infusion site for 5 consecutive days (Mon-Fri)