Safety profile of levonorgestrel intrauterine system: Analysis of spontaneous reports submitted to FAERS

The levonorgestrel-releasing intrauterine system (LNG-IUS) is an established, long-acting contraceptive option. With the widespread use of the LNG-IUS, drug-reported adverse events (AEs) have also garnered significant attention. In this study, we conducted a real-world analysis using the FDA's Adverse Event Reporting System (FAERS) database to assess the incidence of AEs associated with LNG-IUS use. Data from FAERS spanning from 2004Q1 to 2024Q1 were reviewed, with a focus on reports in which LNG-IUS was the primary suspected and secondary suspect drug. Signal detection was carried out utilizing Standardized MedDRA Queries (SMQ) and Preferred Terms (PT), with reporting odds ratio (ROR), proportional reporting ratio (PRR), and information component (IC) employed to identify Signals of Disproportionate Reporting (SDR) for AEs. A positive SDR was defined when all three methods indicated significance. Analysis of 13 SMQs revealed notable SDRs in ear and eye disorders, cardiac arrhythmias, and lipodystrophy. Of the 61 suspected SDRs identified at the PT level, nearly half were not previously documented in labeling. Key potential signals of AEs associated with LNG-IUS use included increased heart rate, papilledema, idiopathic intracranial hypertension, cervical dysplasia, ruptured ovarian cyst, and uterine embedment and perforation. The findings underscore the importance of signal detection using FAERS data for identifying safety concerns related to LNG-IUS. Long-term observational studies are warranted to confirm and further elucidate these potential safety signals.