Conference News Roundup—American Society of Anesthesiologists

Ketamine May Help Treat Medically Refractory Migraine Pain

Ketamine, a medication commonly used for pain relief and increasingly used for depression, may help alleviate migraine pain in patients who have not been helped by other treatments, a study suggests.

The trial of 61 patients found that almost 75% had an improvement in their migraine intensity after a three- to seven-day course of inpatient treatment with ketamine. The drug is used to induce general anesthesia, but also provides powerful pain control for patients with many painful conditions in lower doses than its anesthetic use.

“Ketamine may hold promise as a treatment for migraine headaches in patients who have failed other treatments,” said study coauthor Eric Schwenk, MD, Director of Orthopedic Anesthesia at Thomas Jefferson University Hospital in Philadelphia. “Our study focused only on short-term relief, but it is encouraging that this treatment might have the potential to help patients [in the] long-term. Our work provides the basis for future prospective studies that involve larger numbers of patients.”

An estimated 12% of the US population has migraines. A subset of these patients, along with those who have other types of headaches, does not respond to treatment. During a migraine, people are often sensitive to light and sound and may become nauseated or vomit. Migraines are three times more common in women than in men.

The researchers reviewed data for patients who received ketamine infusions for intractable migraine headaches—migraines that had failed all other therapies. On a scale of 0 to 10, the average migraine headache pain rating at admission was 7.5, compared with 3.4 at discharge. The average length of infusion was 5.1 days, and the day of lowest pain ratings was day 4. Adverse effects were generally mild.

Dr. Schwenk said that while his hospital uses ketamine to treat intractable migraines, the treatment is not yet widely available. Thomas Jefferson University Hospital will open a new infusion center that will treat more patients with headaches using ketamine. “We hope to expand its use to both more patients and more conditions in the future,” he said.

“Due to the retrospective nature of the study, we cannot definitively say that ketamine is entirely responsible for the pain relief, but we have provided a basis for additional larger studies to be undertaken,” Dr. Schwenk added.

Opioid Abuse Plateaus at a High Level

Although the rapid increase in opioid abuse has leveled off, the prevalence of abuse remains high and does not appear to be declining, according to an analysis of national data.

More than 13% of Americans age 12 and older—nearly one in seven—have abused prescription opioids at some point in their lives, researchers determined after analyzing the latest data from the National Survey on Drug Use and Health (NSDUH), an annual survey sponsored by the Substance Abuse and Mental Health Services Administration. Additionally, while 8.6% of Americans abused opioids in 2000, by 2003 that number increased to 13.2%, and it has remained at that level since.

“The amount of opioid prescriptions being written in the United States is breathtaking—essentially enough for every American adult to have a bottle of the pain killers in their medicine cabinet,” said Asokumar Buvanendran, MD, lead author of the study, Director of Orthopedic Anesthesia and Vice Chair for Research at Rush Medical College in Chicago, and chair of the American Society of Anesthesiologists (ASA) Committee on Pain Medicine. “This in turn leads to opioid abuse because people may take more than needed, or the pills fall into the wrong hands. That has got to change.”

Because opioids can produce euphoria, they are highly likely to be abused. Opioid prescriptions are often written for an excessive number of pills, so patients may take more medication than they need and become addicted. Additionally, unused medication can be diverted to another person for illicit use. More than half of the people who misuse prescribed opioids get them from a friend or relative, not a physician, according to NSDUH data.

The NSDUH survey asked Americans whether they had taken prescription opioids without a prescription written for them (which constitutes abuse) anytime in their lives. The researchers determined that in 2014 (the last year for which data was available), 13.6% of Americans had abused prescription opioids. Use of hydrocodone (including Vicodin, a combination of hydrocodone and acetaminophen) increased from 3.2% in 2000 to 9.1% in 2014. Use of oxycontin increased from less than 1% in 2000 to 3% in 2014.

Hydrocodone is the most frequently prescribed and therefore the most frequently abused opioid, researchers noted.

“While the illicit opioid use trend seems to have plateaued, there is no evidence of a decline yet,” said Mario Moric, coauthor of the study and a biostatistician at Rush Medical College. “Hopefully, with increased national attention to the problem we will see a significant drop in abuse.”

“Opioids are still an important tool for dealing with pain, but doctors need to prescribe smaller quantities,” said Dr. Buvanendran. “Also, patients need to be educated about the dangers of overuse and abuse and understand that pain usually cannot be solved solely with a pill, but needs to include exercise, physical therapy, eating right, having a social support system, and developing good coping skills.”

The ASA is committed to ending opioid abuse and has launched several initiatives to combat the epidemic.