Regular use of acetaminophen or acetaminophen–codeine combinations and prescription of rescue therapy with non-steroidal anti-inflammatory drugs: a population-based study in primary care

Abstract

Objective: There are contrasting positions concerning the benefit–risk ratio of acetaminophen use for osteoarthritis (OA)-related pain. To clarify the effectiveness of acetaminophen or acetaminophen–codeine combinations according to their regimen of use, we evaluated whether being a regular user (adherent) of these medications decreased the occurrence of rescue therapy with non-steroidal anti-inflammatory drugs (NSAIDs).

Methods: Using the Health Search IMS Health Longitudinal Patient Database, we formed a cohort of patients aged ≥18 years and newly treated with acetaminophen or acetaminophen–codeine combinations for OA between 1 January 2001 and 31 December 2013. These patients were followed up for one year in which they were categorized as regular or irregular users of these medications according to a variable medication possession ratio (VMPR) ≥ 50% or lower. We operationally defined the rescue therapy as the use of any NSAIDs prescribed for OA-related pain.

Results: Overall, 40,029 patients (69.5% females; mean age: 68 ± 13.57) treated with acetaminophen or acetaminophen–codeine combinations formed the cohort. After the first year of treatment, regular users showed a statistically significantly lower risk of being prescribed with rescue therapy with NSAIDs (OR = 0.89; 95% CI 0.84–0.96).

Conclusion: These findings show that regular use of acetaminophen or acetaminophen–codeine combinations may reduce the need for NSAIDs to treat OA-related pain.

Keywords:

• Acetaminophen
• acetaminophen–codeine
• osteoarthritis
• adherence
• pain
• primary care

Transparency

Declaration of funding

This work was supported by the Italian College of General Practitioners and Primary Care.

Declaration of financial/other relationships

F.L. and I.C. have disclosed that they have provided consultancies in protocol preparation for epidemiological studies and data analyses for IBSA and Angelini. C.C. and P.L.A. have disclosed that they have provided clinical consultancies for IBSA, Angelini, Grunenthal, Alfa Wasserman, Pfizer, Prostrakan, Molteni, Dompè and Teva. A.F. has disclosed that she has provided clinical consultancies for IBSA. A. V., N. L., M. S. and D. F. have no conflict of interest to disclose.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.