Using a morphine equivalence metric to quantify opioid consumption: examining the capacity to provide effective treatment of debilitating pain at the global, regional, and country levels

Context: Morphine has been considered the gold standard for treating moderate-to-severe pain, although many new opioid products and formulations have been marketed in the last two decades and should be considered when examining opioid consumption. Understanding opioid consumption is improved by using an equianalgesic measure that controls for the strengths of all examined opioids.

Objectives: The research objective was to use a morphine equivalence (ME) metric to determine the extent that morphine consumption relates to the total consumption of all other study opioids.

Methods: An ME metric was created for morphine and the aggregate consumption of each study opioid (Total ME), adjusted for country population to allow for uniform equianalgesic comparisons. Graphical and statistical evaluations of morphine use and Total ME consumption trends (between 1980 and 2009) were made for the global and geographic regional levels and selected developed and developing countries.

Results: Global morphine consumption rose dramatically in the early 1980s but has been significantly outpaced by Total ME since 1996. As expected, the extent of morphine and Total ME consumption varied notably among regions, with the Americas, Europe, and Oceania regions accounting for the highest morphine use and Total ME in 2009. Developing and least developed countries, compared with developed countries, demonstrated lower overall Total ME consumption.

Conclusion: Generally, worldwide morphine use has not increased at the rate of Total ME, especially in recent years. Examining a country's ability to effectively manage moderate-to-severe pain should extend beyond morphine to account for all available potent opioids.