Objective: The extent to which people comply with labeled instructions for use of long-acting over-the-counter analgesics is largely unknown; this study evaluated whether consumers can correctly select and use a new long-acting ibuprofen 600-mg immediate-release and extended-release (IR/ER) product.
Design: A single open-label study with participants randomly assigned to 2 substudies. Self-selection substudy: participants estimated duration of their last pain episode, then selected ibuprofen IR/ER or standard ibuprofen IR for a similar episode. Compliance substudy: participants purchased and recorded real-world use of ibuprofen IR/ER in daily diaries over 30 days.
Setting: Eighteen U.S. pharmacies.
Participants: Consumers age 12 years or older who used an average of ≥5 doses per month of an over-the-counter analgesic in the past 3 months.
Intervention: Self-selection: questionnaire only. Compliance: ibuprofen IR/ER as needed.
Main outcome measures: Self-selection: percentage who correctly selected or avoided selecting ibuprofen IR/ER based on anticipated pain duration. Compliance: proportion who were excessive users (use for >10 of 30 days and averaging >1600 mg/d, or >20 tablets over ≤10 days and averaging >1600 mg/d).
Results: Self-selection substudy (N = 249): on the primary endpoint, 69.1% (95% confidence interval [CI], 63.3%-74.8%) overall made a correct selection-63.5% (95% CI, 57.5%-69.4%) correctly selected ibuprofen IR/ER for pain ≥6 hours and 5.6% (95% CI, 2.8%-8.5%) correctly avoided selecting ibuprofen IR/ER for shorter-lasting pain. Overall, 82.7% (95% CI, 77.6%-87.8%) chose correctly when subjects who picked ibuprofen IR for pain ≥6 hours (a "missed opportunity," not an incorrect selection) were excluded. Compliance substudy (N = 405): only 5 participants (1.2%; 95% CI, 0.2%-2.3%) were excessive users; all took ibuprofen IR/ER for >10 days, averaging 1821 mg/day (range, 1661.5-2072.7 mg/d). No excessive user experienced an adverse event.
Conclusion: Although the study did not meet the a priori primary efficacy outcome target, the majority of participants selected and used ibuprofen 600-mg IR/ER tablets correctly per the labeled instructions.
Trial registration: ClinicalTrials.gov NCT01789606.
Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.