Study Maps IV Morphine Equivalence of Sublingual Sufentanil

Author: Ethan Covey

Anesthesiology News

A single dose of a 15-mcg sublingual sufentanil tablet (ssT) offers analgesic relief equivalent to 2.5 mg of IV morphine, and is an effective alternative to IV morphine in surgical patients with moderate to severe postoperative pain.

“We are constantly striving to improve our patients’ pain experience,” said Harold S. Minkowitz, MD, an anesthesiologist at the Department of Anesthesiology at Memorial Hermann Memorial City Medical Center, in Houston.

Recognizing that an estimated 20% to 40% of patients experience severe pain after surgery, and as many as 70% of patients report moderate to severe pain upon ER discharge, Dr. Minkowitz and his colleagues sought to test the IV morphine equivalence of two new sublingual sufentanil products.

“Sublingual sufentanil will be an excellent option for patients that now require intravenous opioids in the supervised medical setting,” Dr. Minkowitz said. Yet, the researchers noted that while many U.S. physicians are familiar with sufentanil citrate injection—marketed as Sufenta (Taylor Pharmaceuticals)—familiarity with sublingual sufentanil is low. Currently, a 15-mcg ssT (Zalviso, AcelRx Pharmaceuticals) is approved for use in Europe, whereas a 30-mcg tablet was approved recently in the United States (Dsuvia, AcelRx).

Although these advances may make ssT a promising medicine, concerns regarding dosage and appropriate use remain. “As with any opioid, appropriate monitoring is always required,” Dr. Minkowitz said.

Evaluating Equivalency

The study tracked adults scheduled to undergo open abdominal or major orthopedic surgery who were randomly assigned to receive either 15 mcg of ssT or IV patient-controlled morphine sulfate. Pain intensity was determined via patient global assessment over the 48-hour study period, with successful pain management being recorded as the proportion of patients who rated their pain control as good or excellent. Drug utilization was tracked by recording the number of doses of study drug administered, from which the average hourly dosage was calculated. Safety assessments, including adverse events, vital signs, oxygen saturation and lab values, also were tracked.

Of the 357 participating patients, 78.5% receiving ssT and 65.6% receiving IV PCA morphine achieved successful pain management. This demonstrated both noninferiority, based on 95% CI, as well as statistical superiority in favor of the ssT 15-mcg group (P=0.007).

Upon reviewing dosage data, the researchers calculated that a dose of 15 mcg of ssT was equal to approximately 2.5 mg of IV morphine. Similarly, a single 30-mcg ssT dose would be equivalent to 5 mg of IV morphine.

Risks Remain

Among some anesthesiologists, however, there were concerns that ssT may still present serious risks for abuse if poorly handled.

“This study does help provide information that can be utilized to aid prescribers in proper dosing of the medication,” said Eric Michel, DO, an interventional pain management fellow at SUNY Upstate Medical University, in Syracuse, N.Y. “However, while the sublingual formulation may help improve the efficiency of pain management in the emergency room or outpatient surgical center, the ease of administration will make it a popular drug of abuse if it makes its way to the black market. … IV fentanyl is also not available for outpatient use, and somehow it seems to have made its way onto the streets. How can they be so sure the same won’t happen with sublingual sufentanil?” Implementing the details of adequate monitoring will be key.

The study was originally presented at the fall 2018 annual meeting of the American Society of Regional Anesthesia and Pain Medicine.