Nefopam Misuse: A Cross-Sectional Study in France

Abstract

Background: Nefopam is a non-opioid analgesic. Nefopam is increasingly prescribed in contraindicated populations, raising questions about the appropriate use of nefopam. This study aimed to evaluate nefopam use in France according to age, epilepsy status and socioeconomic status.

Methods: This retrospective observational study was conducted from January 1, 2016, to December 31, 2022. Data on nefopam use in France were retrieved from the national health insurance information system.

Results: Between 2016 and 2022, 51.8 million boxes of nefopam were dispensed to 6.5 million patients, with a mean age of 56 years and a male-to-female sex ratio of 0.6. Nefopam use increased by 121.7%, whereas codeine use and tramadol use decreased by 7% and 17% respectively, raising the market share of nefopam from 5.0% to 11.6%. Nefopam use increased 2.8-fold in patients under 15 years and 1.7-fold in patients over 65 years, after standardisation. Nefopam use increased 1.7-fold in patients with epilepsy and 1.2-fold in patients with a disadvantaged socioeconomic status. The cost of nefopam was 4.3 times higher than alternative drugs. During the period 2016-2022, 8.23% of the general population received 1 to 4 boxes of nefopam per year, 4.68% received 6 to 19 boxes per year, and 0.91% received ≥ 20 boxes per year.

Conclusions: This study highlights a widespread inappropriate use of nefopam, especially in contraindicated populations and vulnerable groups. The recent availability of the oral form in France may worsen these patterns. Close national and European monitoring is important to assess the extent of such practices and guide future regulation.

Significance statement: This work is a snapshot of nefopam usage in France. It sheds light on contraindicated uses (in subjects under 15 years of age or with epilepsy), not recommended uses (chronic usage, or in the elderly) and reports the usage of this treatment in the most deprived patients. This article cautions against underestimating the dangers and pitfalls of this treatment, especially in light of mounting evidence of pharmacodependence.

FIGURE 1

(A) Cumulative standardised rate of nefopam consumption in the general population, adjusted to the 2022 INSEE age and sex distribution. (B) Age‐ and sex‐stratified standardised rates of nefopam consumption across population subgroups.

FIGURE 2

(A) Proportion of patients with disadvantaged socioeconomic status among nefopam users, compared to the proportion in the general population in France. (B) Proportion of patients with disadvantaged socioeconomic status among chronic nefopam users, compared to the proportion in the general population in France.

FIGURE 3

Standardised rate of nefopam prescriptions among individuals with epilepsy, by year, age, and sex, adjusted to the 2022 INSEE age and sex distribution.

FIGURE 4

Histogram of consumption of nefopam in the overall French population. Panel A shows the proportion of the general population and the number of boxes of nefopam they received per year (from January to December) computed as the average of 7 years (2016 to 2022) and panel B shows the proportion of the general population and the number of months they received nefopam during the period 2016–2022.