August 20, 2014 — The U.S. Judicial Panel on Multidistrict Litigation (JPML) has received a petition to centralize 28 lawsuits involving severe withdrawal symptoms after discontinuing Cymbalta (duloxetine), an antidepressant.

Lawsuits have been filed in Maryland, Georgia, Louisiana, Florida, Pennsylvania, and California. Because ten of the lawsuits are already located in California, plaintiffs are asking the JPML to consolidate the litigation in the U.S. District Court for the Central District of California for coordinated pretrial proceedings.

The plaintiffs all accuse Eli Lilly & Co., the manufacturer of Cymbalta, of failing to provide adequate warnings about the risk of withdrawal symptoms.

Eli Lilly claims that warnings adequately state that withdrawal symptoms “occurred at a rate greater than or equal to 1 percent.” Clinical trials found that about 50% experienced withdrawal symptoms.

Many patients want Eli Lilly to add warnings about “brain zaps” — a feeling like an electrical buzz or shiver in the brain — when they try to stop taking Cymbalta. Other reported effects include dizziness, nausea, headache, fatigue, vomiting, irritability, nightmares, insomnia, diarrhea, anxiety, profuse sweating and vertigo.

The link between Cymbalta and withdrawal was first identified in clinical trials. Patients were given Cymbalta for 8-9 weeks, abruptly switched to a placebo, and monitored for 1-2 more weeks. About half of patients suffered withdrawal symptoms, including 10% classified as “severe.” In a majority of cases, symptoms did not resolve after the monitoring period was over.

Although the Prescribing Information for Cymbalta includes warnings against stopping an antidepressant due to the risk of “other symptoms,” it does not explain what these symptoms may include, severity, or ways to mitigate the risk. Although the FDA has received dozens of reports of withdrawal, they have not strengthened warnings.