11121 Background: Ivermectin, an antiparasitic agent not indicated for cancer treatment, has received public attention since early January 2025 due to widespread discussion on social media and other non-clinical forums. Little is known about whether the increased visibility may influence medication use or reporting among patients with cancer in real-world clinical data. Methods: We conducted a retrospective descriptive analysis using the EPIC COSMOS, a large, multi-institutional U.S. electronic health record network. We identified all ivermectin medication records from quarter (Q)1 2024 to Q3 2025, including prescribed/administered and patient-reported medications linked to clinical encounters. Our primary outcome was the quarterly trend in the percentage of ivermectin records where cancer was listed as the primary diagnosis for the encounter. Secondary measures included other diagnosis associated with the encounter (e.g., parasitic) and patient demographics. Results: We identified 96,525 ivermectin medication records, increasing from 11,854 in Q1 2024 to 15,223 in Q3 2025. The proportion of records with cancer as the primary diagnosis increased modestly during 2024 (from 2.3% to 3.1%; average quarterly increase=0.2 percentage points ppts), followed by a larger increase in Q1 2025 (from 3.1% to 4.2%, adjusted increase=1.0 ppts, relative increase=32%, p<.001), which stabilized in Q2 and declined slightly in Q3 2025. The surge from Q4 2024 to Q1 2025 was larger for patient-reported ivermectin (from 156 to 231 records, 48% increase) than prescribed/administered medications (292 to 347 records, 19% increase). In contrast, the proportion of ivermectin records associated with strongyloidiasis, onchocerciasis, or scabies ranged from 18.5%–19.5% in 2024 and declined to 17.1% in Q1 2025, while records associated with other infectious conditions remained stable (~49%). Among records with cancer as the primary diagnosis (n=3,157), mean patient age was 62 years, with 46% female, 76% White, 8% Black, and 10% Hispanic; the proportion prescribed to White patients increased from 71% in Q4 2024 to 81% in Q1 2025. Physician specialty distribution associated with prescribed/administered ivermectin was 35% oncologists, 20% primary care, 22% dermatologists, 4.2% advanced practice providers, and 19% other specialties. Conclusions: Although ivermectin use in cancer care remained uncommon overall, real-world data show a rapid, largely patient-driven increase during Q1 2025. This rise is distinct from the stable or declining proportions of records linked to approved parasitic indications. These findings suggest that social trends may shape medication use, highlighting the importance of careful medication reconciliation and patient counseling in oncology settings to address non-evidence-based use.
Jiang et al. (Wed,) studied this question.