Over-the-counter fish oil use in a county hospital: Medication use evaluation and efficacy analysis

Abstract

BACKGROUND Little is known about the use and effectiveness of over-the-counter (OTC) fish oil supplements for triglyceride (TG) lowering. OBJECTIVES To (1) perform a medication-use evaluation (MUE) and (2) assess the efficacy of OTC fish oil. METHODS Retrospective, observational cohort study using electronic medical records and the pharmacy database from Parkland Health and Hospital System in Dallas, Texas. Parkland is a tax-supported county institution that provides patients with single-brand OTC fish oil. Two separate analyses were conducted. Six hundred seventeen patients (prescribed fish oil between July 1, 2012, and August 31, 2012) were included in the MUE analysis and 235 patients (109 fish oil, 72 fenofibrate, and 54 gemfibrozil, prescribed between January 1, 2012, and July 31, 2013) were included in the efficacy analysis. The main outcome measure for the MUE was fish oil prescribing habits including dosages and patient adherence, as defined by medication possession ratio. The main outcome measure for the efficacy analysis was change in lipids measured using the last value before fish oil treatment and the first value after fish oil treatment. RESULTS MUE: 617 patients received prescriptions for OTC fish oil. Sixty-four percent were prescribed a total daily dose of 2000 mg. Only 25% of patients were adherent. Efficacy analysis: despite being prescribed suboptimal doses, fish oil reduced TGs by 29% (95% confidence interval, 34.3–22.7). Compared with fish oil therapy, fibrate therapy resulted in a greater TG reduction: 48.5% (55.1–41.0) with fenofibrate and 49.8% (57.6–40.5) with gemfibrozil (P < 0001, both medications compared with fish oil). CONCLUSIONS Health care providers prescribe suboptimal doses of fish oil, and adherence is poor. Even at low doses (2 g/d), though, fish oil lowers TGs by 29%.