Ketamine Infusions: 24 Months of Real-World Data

Ketamine Infusions: 24 Months of Real-World Data

Ketamine has been used off-label for fibromyalgia pain for years, largely on the strength of small studies with short follow-up. In August 2026, the Journal of Pain Research published the largest and longest dataset so far: 92 patients followed for up to 24 months.

The findings are encouraging for a subset of patients, and the study's limitations matter as much as its results.

About the Study

This was a retrospective chart review — researchers looked back at records rather than running a prospective trial. It covered 92 consecutive women treated at the Carolinas Pain Institute in Winston-Salem, North Carolina, between January 2018 and December 2024. All were women, aged 24 to 78 (median 49), with a median BMI of 32.4.

Protocol used:

• Single-day intravenous ketamine at approximately 1.5 mg/kg/hour over 3 hours (300–500 mg total), under monitored sedation with midazolam
• Three loading infusions one week apart
• Then repeated every 3 to 10 months (median 6 months)

Ketamine was used as an adjunct to existing treatment, not as a replacement for it.

The Results

• Median pain score fell from 8 at baseline to 5 at 3 months, and held at 5 through 24 months.
• At 3 months, 32 of 92 patients reported more than 50% pain relief. At 24 months, 30 of 92 still did — roughly one in three.
• 75% achieved at least a 2-point reduction at 24 months, which meets the threshold for clinically meaningful improvement.
• 58% reported more than 30% relief at 24 months.
• 19 patients — about one in five — reported minimal or no benefit.

Opioid Use

The number of patients taking opioids fell from 33 at baseline to 27 at 24 months. However, the median daily morphine-equivalent dose among those still taking opioids was unchanged at 30 mg. Ketamine reduced how many patients needed opioids, not how much the remaining patients needed.

Side Effects

Nineteen patients reported side effects. The most common were nausea (12), hallucinations (10), and vomiting (3). One patient experienced confusion and two reported post-infusion nightmares. There were no serious adverse events.

Why the Limitations Matter

A retrospective single-arm study cannot establish that ketamine caused the improvement. Several specific factors weaken the conclusion:

• No control group. Patients receiving infusions every few months also receive attention, monitoring, and hope. Placebo response in fibromyalgia trials is consistently high.
• Medication changes were common. Most patients changed other medications during the follow-up period, so improvement cannot be attributed to ketamine alone.
• It was an adjunct, not monotherapy. Results describe ketamine added to ongoing care, which is how it is realistically used, but it also means the effect is not isolated.
• Ketamine for fibromyalgia remains off-label. It is not approved for this condition.

The authors are straightforward that these results justify a large randomized prospective trial rather than clinical adoption on their own.