Pain management with ketamine infusion: Most patients may experience side effects, study suggests

ORLANDO, Fla. – Ketamine use has grown as a pain management alternative but more than one in three patients may experience side effects such as hallucinations and visual disturbances, suggests new research presented at the ANESTHESIOLOGY® 2019 annual meeting.

Ketamine is a powerful anesthetic that is also used to treat acute and chronic pain and depression. While the drug is known for some side effects that negatively affect mental status, there are many other potential risks. Recent consensus guidelines from the American Society of Regional Anesthesia and Pain Medicine, American Academy of Pain Medicine and American Society of Anesthesiologists (ASA) support ketamine infusion therapy for acute pain management, but the groups note more studies are needed to determine the best approach for using it safely and effectively.

"Despite the U.S. Food and Drug Administration's approval of ketamine for multiple uses, including general anesthesia and treatment of depression, the effects of using the drug at low doses to treat pain have not been extensively studied," said Padma Gulur, M.D., lead author, member of ASA's Committee on Pain Medicine and professor of anesthesiology at Duke University in Durham, North Carolina. "Our research aimed to determine both short- and long-term side effects of low dose ketamine when used for pain treatment."

Researchers conducted a review of side effects related to ketamine infusions for pain management. Reported side effects were categorized into two groups: those directly linked to ketamine (hallucinations, vivid dreams, out-of-body experience and/or unusual thoughts) and those associated with using ketamine in combination with other drugs (sedation, visual disturbances and urinary dysfunction).

Of 297 Duke University pain patients who received ketamine infusion therapy between January and June 2017, 104 (35%) reported significant side effects. Twenty per cent of these patients suffered side effects directly linked to ketamine, while 15% experienced side effects associated with the use of ketamine in combination with other drugs.

"Although the opioid epidemic has prompted the medical community to thoroughly investigate pain management alternatives, our number one priority is to ensure the safety of patients receiving ketamine," said Dr. Gulur. "More than one in three patients reported significant side effects from ketamine infusions that required ongoing monitoring or resulted in discontinuation of therapy. More research on the impact of ketamine use for pain on the population is needed."