Janssen Korea released NUCYNTA ER, a new oral opioid drug for chronic pain, Monday, which it said has less “adverse effects, such as nausea, vomiting, and constipation in comparison with existing narcotic analgesics.”

Chronic pain refers to neuropathic pain that persists after more than three months of treatment, reportedly inflicting more than 10 percent of Koreans.

“Clinical results have shown promising results regarding safety, effectiveness and side effects,” said Professor Seo Jeong-hoon at Asan Hospital, citing constipation and nausea as two major adverse effects of the existing opioid drugs. “Patients that took Nucynta have found constipation decrease 15.4 percent, and vomiting fall 7.37 percent compared to patients who took other drugs, such as Oxycodone or Naloxone, during the clinical trial.”

Clinical experiments also showed that 62.5 percent of patients in the oxycodone group dropped out of the study because of adverse effects and other reasons, while only 33.8 percent of patients taking Nucynta discontinued the tests.

Professor Seo said more data is needed to prove efficiency despite positive results. He warned that doctors should not prescribe these drugs in the long-term, as it could lead to addiction and severe side effects.

Kim Oak-yeon, president of Janssen Korea, said, “The introduction of Nucynta provides an important additional treatment option for patients living with chronic pain, with a favorable tolerability profile that can help improve their quality of life.”