The PharmERToxGuy

Ketamine for Acute Geriatric Pain in the ED

Subdissociative-dose ketamine (SDK) provides effective analgesia with lower rates of unwanted side effects when administered as a slow IV infusion. However, safety and efficacy studies have excluded geriatric patients until now, when Dr. Sergey Motov and colleagues strike again. SDK offers a much-needed pain management strategy for moderate to severe pain in this population who are often not ideal candidates for opioid analgesia.

What They Did

What They Found

Application to Clinical Practice

SDK provided greater analgesia compared to morphine 15 minutes post-administration with similar efficacy at 30, 60, 90, and 120 mins. However, this study was terminated at the interim analysis and did not have adequate power to detect a true analgesic difference. Likewise, although there was a statistically significant difference between frequency of adverse events, this study lacked power to detect a true difference between treatment groups (it should be noted that up to 86.7% of patients had some adverse effect with SDK vs. 46.7% with morphine).

With that said, SDK may be considered an effective pain management option in the geriatric ED population as satisfactory analgesia was obtained and adverse effects reported were short lived and rarely required intervention. Furthermore, as analgesic SDK doses range from 0.1-0.3 mg/kg, utilizing a lower dose to begin may result in less adverse events with the option of repeat dosing if satisfactory analgesia is not achieved.

Bottom Line

In this small study, SDK compared favorably to morphine for treating acute pain in geriatric ED patients. However, adverse effects were common and should be a factor when considering the benefit to risk ratio in this patient population.


Motov S, et al. Intravenous subdissociative-dose ketamine versus morphine for acute geriatric pain in the Emergency Department: A randomized controlled trial. Am J Emerg Med. 2018 May 16. Epub ahead of print. PMID 29807629