Manufacturers Win Ranitidine NDMA Case as NHIS Waives Appeal

Pharmaceutical companies including Kuhnil Pharmaceutical have secured a final victory in a lawsuit seeking the return of unjust enrichment related to NDMA impurities in ranitidine products against the National Health Insurance Service (NHIS). With the insurer opting not to appeal, legal experts say the ruling could spur similar claims.

The Seoul Central District Court ruled entirely in favor of the plaintiffs—22 pharmaceutical companies—in a suit over reimbursement demands tied to NDMA impurities detected in ranitidine, nizatidine, and metformin.

According to HIT News, the NHIS declined to appeal. Although it received the certified judgment on Jan. 16, the insurer did not file within the two-week statutory window, allowing the decision to become final and ending the more than three-year dispute in the manufacturers’ favor.

The case traces back to NDMA impurity findings that began with valsartan in 2018 and later expanded to ranitidine, nizatidine, and metformin. While the government initially covered re-prescription and re-dispensing costs through the NHIS, it sought reimbursement from manufacturers in 2021. After paying under protest, 22 companies—including Kuhnil—filed suit in July 2022 to recover the funds.

The plaintiffs argued their products were manufactured and managed in line with then-applicable international standards and regulatory approvals, making retroactive liability for unforeseeable impurities unjust. The court agreed, finding no legal basis for the NHIS’s reimbursement claims and no manufacturer liability. With the appeal waived, the judgment is final.

The NHIS is expected to return about $760,000 in principal plus roughly $140,000 in statutory interest accrued over three years. On Feb. 2, it reportedly notified the 22 companies that payments, including delay damages, would be disbursed upon receipt of required documentation.

Industry observers say amounts once deemed “clearly recoverable” were ultimately classified as unjust enrichment, a determination that could have wide implications. Dong-jun Lee of Lee & Lee Law Firm noted that missing the appeal deadline makes the ruling binding and obligates repayment of both principal and statutory interest. He added that companies that previously refrained from challenging reimbursements may now consider litigation, as unjust-enrichment claims carry a five-year statute of limitations from the date of payment.