Opioid use disorder remains a significant and rapidly evolving public health concern worldwide, as opioids account for two-thirds of drug-related deaths.[4]United Nations Office on Drugs and Crime. World drug report 2024. 2024 [internet publication].
https://www.unodc.org/unodc/en/data-and-analysis/world-drug-report-2024.html
The number of opioid users worldwide has nearly doubled since 2010.[4]United Nations Office on Drugs and Crime. World drug report 2024. 2024 [internet publication].
https://www.unodc.org/unodc/en/data-and-analysis/world-drug-report-2024.html
As of 2022, there were approximately 60 million people worldwide who used opioids, 30 million of whom used opiates (mainly heroin).[4]United Nations Office on Drugs and Crime. World drug report 2024. 2024 [internet publication].
https://www.unodc.org/unodc/en/data-and-analysis/world-drug-report-2024.html
In the US, the number of opioid prescriptions began to expand significantly in the 1990s, driven by multiple factors such as: aggressive marketing, increased clinical focus on pain management, and the launch of a sustained-release formulation of oxycodone.[5]DeWeerdt S. Tracing the US opioid crisis to its roots. Nature. 2019 Sep;573(7773):S10-2.
https://www.nature.com/articles/d41586-019-02686-2
http://www.ncbi.nlm.nih.gov/pubmed/31511672?tool=bestpractice.com
Prescription of opioids for acute and chronic pain, and subsequent opioid use disorders, quickly became widespread, establishing an opioid crisis.[5]DeWeerdt S. Tracing the US opioid crisis to its roots. Nature. 2019 Sep;573(7773):S10-2.
https://www.nature.com/articles/d41586-019-02686-2
http://www.ncbi.nlm.nih.gov/pubmed/31511672?tool=bestpractice.com
This was followed by a resurgence of the heroin market in around 2010, driven by an increase in demand from people addicted to prescription opioids.[6]Humphreys K, Shover CL, Andrews CM, et al. Responding to the opioid crisis in North America and beyond: recommendations of the Stanford-Lancet Commission. Lancet. 2022 Feb 5;399(10324):555-604.
http://www.ncbi.nlm.nih.gov/pubmed/35122753?tool=bestpractice.com
A third wave of the crisis began in 2014, characterised by further increases in addiction and fatal drug overdoses linked to synthetic opioids such as fentanyl.[6]Humphreys K, Shover CL, Andrews CM, et al. Responding to the opioid crisis in North America and beyond: recommendations of the Stanford-Lancet Commission. Lancet. 2022 Feb 5;399(10324):555-604.
http://www.ncbi.nlm.nih.gov/pubmed/35122753?tool=bestpractice.com
Subsequently, there has been an estimated 95% decrease in opium poppy production between 2022 and 2023 in Afghanistan. This production change will likely have a global impact on opioid markets, potentially causing an increased demand for alternative substances.[4]United Nations Office on Drugs and Crime. World drug report 2024. 2024 [internet publication].
https://www.unodc.org/unodc/en/data-and-analysis/world-drug-report-2024.html
Trends in opioid use disorder prevalence in the US are difficult to assess due to limitations in direct survey data. Using multiplier methods to adjust for underreporting, estimates suggest that opioid use disorder prevalence increased from 2010 to 2014, then stabilised and slightly declined each year until 2019.[7]Keyes KM, Rutherford C, Hamilton A, et al. What is the prevalence of and trend in opioid use disorder in the United States from 2010 to 2019? Using multiplier approaches to estimate prevalence for an unknown population size. Drug Alcohol Depend Rep. 2022 Jun:3:100052.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9248998
http://www.ncbi.nlm.nih.gov/pubmed/35783994?tool=bestpractice.com
This is potentially related to the implementation of stricter prescribing regulations. In 2022 an estimated 3.7% of adults in the US needed treatment for opioid use disorder; of these, 25.1% received pharmacotherapy and 30.0% received treatment for opioid use disorder without pharmacotherapy.[8]Dowell D, Brown S, Gyawali S, et al. Treatment for opioid use disorder: population estimates - United States, 2022. MMWR Morb Mortal Wkly Rep. 2024 Jun 27;73(25):567-74.
https://www.cdc.gov/mmwr/volumes/73/wr/mm7325a1.htm
http://www.ncbi.nlm.nih.gov/pubmed/38935567?tool=bestpractice.com
The US has experienced a 24-fold increase in opioid-related deaths since 2010, driven largely by increases in potent illicitly-manufactured types of fentanyl.[9]United Nations Office on Drugs and Crime. Key findings and conclusions. Jun 2024 [internet publication].
https://www.unodc.org/unodc/en/data-and-analysis/wdr2024-key-findings-conclusions.html
The rate of overdose deaths in the US involving synthetic opioids increased by 64% between 2019 and 2022, although between 2022 and 2023 there was a slight decline.[10]National Institute on Drug Abuse. Drug overdose deaths: facts and figures. Aug 2024 [internet publication].
https://nida.nih.gov/research-topics/trends-statistics/overdose-death-rates
Opioid-related deaths have increased at higher rates among black Americans.[11]Wilson N, Kariisa M, Seth P, et al. Drug and opioid-involved overdose deaths - United States, 2017-2018. MMWR Morb Mortal Wkly Rep. 2020 Mar 20;69(11):290-7.
https://www.cdc.gov/mmwr/volumes/69/wr/mm6911a4.htm
http://www.ncbi.nlm.nih.gov/pubmed/32191688?tool=bestpractice.com
Studies prior to 2016 estimated that over 25% of opioid-related deaths in the US also involved benzodiazepines.[12]Park TW, Saitz R, Ganoczy D, et al. Benzodiazepine prescribing patterns and deaths from drug overdose among US veterans receiving opioid analgesics: case-cohort study. BMJ. 2015 Jun 10;350:h2698.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4462713
http://www.ncbi.nlm.nih.gov/pubmed/26063215?tool=bestpractice.com
[13]Sun EC, Dixit A, Humphreys K, et al. Association between concurrent use of prescription opioids and benzodiazepines and overdose: retrospective analysis. BMJ. 2017 Mar 14;356:j760.
https://www.bmj.com/content/356/bmj.j760.long
http://www.ncbi.nlm.nih.gov/pubmed/28292769?tool=bestpractice.com
[14]Jeffery MM, Hooten WM, Jena AB, et al. Rates of physician coprescribing of opioids and benzodiazepines after the release of the Centers for Disease Control and Prevention guidelines in 2016. JAMA Netw Open. 2019 Aug 2;2(8):e198325.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6681551
http://www.ncbi.nlm.nih.gov/pubmed/31373650?tool=bestpractice.com
Updated US Centers for Disease Control and Prevention guidelines advising against concurrent opioids and benzodiazepines led to a decrease in co-prescription; however, whether this translates to a decrease in mortality is not yet clear.[14]Jeffery MM, Hooten WM, Jena AB, et al. Rates of physician coprescribing of opioids and benzodiazepines after the release of the Centers for Disease Control and Prevention guidelines in 2016. JAMA Netw Open. 2019 Aug 2;2(8):e198325.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6681551
http://www.ncbi.nlm.nih.gov/pubmed/31373650?tool=bestpractice.com
Co-use of synthetic opioids, such as fentanyl, with other central nervous system depressants, including animal tranquilisers such as xylazine and medetomidine, is an emerging and concerning trend in the US that further complicates the ongoing crisis of opioid-related overdose deaths.[15]Zhu DT, Cano M. Fentanyl-xylazine overdose deaths in the USA, 2018-2023. Inj Prev. 2025 Apr 2:ip-2024-045596.
https://injuryprevention.bmj.com/content/early/2025/04/01/ip-2024-045596.long
http://www.ncbi.nlm.nih.gov/pubmed/40175084?tool=bestpractice.com
[16]Palamar JJ, Krotulski AJ. Medetomidine infiltrates the US illicit opioid market. JAMA. 2024 Nov 5;332(17):1425-6.[17]Zhu DT, Palamar JJ. Responding to medetomidine: clinical and public health needs. Lancet Reg Health Am. 2025 Apr;44:101053.
https://www.thelancet.com/journals/lanam/article/PIIS2667-193X(25)00063-8/fulltext
In Europe, opioid usage has remained fairly stable since 2016, with a prevalence of 0.3% reported in the European Union (EU) in 2022.[18]European Union Drugs Agency. Heroin and other opioids - the current situation in Europe (European Drug Report 2024). Jun 2024 [internet publication].
https://www.euda.europa.eu/publications/european-drug-report/2024/heroin-and-other-opioids_en#level-2-section0
Heroin remains the dominant illicit opioid used in Europe; synthetic opioids such as fentanyl are currently less prevalent than in the US, although are becoming an emerging problem in some locations.[18]European Union Drugs Agency. Heroin and other opioids - the current situation in Europe (European Drug Report 2024). Jun 2024 [internet publication].
https://www.euda.europa.eu/publications/european-drug-report/2024/heroin-and-other-opioids_en#level-2-section0
In Africa, non-medical use of tramadol is a growing concern, with over 90% of global tramadol-related seizures occurring there.[4]United Nations Office on Drugs and Crime. World drug report 2024. 2024 [internet publication].
https://www.unodc.org/unodc/en/data-and-analysis/world-drug-report-2024.html
In South-West Asia, opioid use is high, with an estimated 3.2% of adults using opioids in the past year. Opiates such as heroin (in Pakistan and India) and opium (in Afghanistan and Iran) are the main substances misused, though non-medical use of pharmaceutical opioids is also substantial.[4]United Nations Office on Drugs and Crime. World drug report 2024. 2024 [internet publication].
https://www.unodc.org/unodc/en/data-and-analysis/world-drug-report-2024.html
Nitazenes, synthetic opioids which have since 2019 appeared on the illegal drugs market in some parts of the world (Asia, Europe, North America, Oceania, and South America), pose an emerging threat to public health due to their extremely high potency.[4]United Nations Office on Drugs and Crime. World drug report 2024. 2024 [internet publication].
https://www.unodc.org/unodc/en/data-and-analysis/world-drug-report-2024.html
In parallel with increasing worldwide prevalence among the general population, an increase in opioid use has been observed in pregnancy.[19]Blanco C, Volkow ND. Management of opioid use disorder in the USA: present status and future directions. Lancet. 2019 Apr 27;393(10182):1760-72.
http://www.ncbi.nlm.nih.gov/pubmed/30878228?tool=bestpractice.com
In 2022, approximately 14.1% of women reported the use of prescription opioid analgesics during pregnancy, with 1 in 5 of these reporting misuse.[20]Nechuta S, Mukhopadhyay S, Golladay M, et al. Trends, patterns, and maternal characteristics of opioid prescribing during pregnancy in a large population-based cohort study. Drug Alcohol Depend. 2022 Apr 1;233:109331.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10838571
http://www.ncbi.nlm.nih.gov/pubmed/35149439?tool=bestpractice.com
[21]Ko JY, D'Angelo DV, Haight SC, et al. Vital signs: prescription opioid pain reliever use during pregnancy - 34 U.S. jurisdictions, 2019. MMWR Morb Mortal Wkly Rep. 2020 Jul 17;69(28):897-903.
https://www.cdc.gov/mmwr/volumes/69/wr/mm6928a1.htm
http://www.ncbi.nlm.nih.gov/pubmed/32673301?tool=bestpractice.com
Frequency of opioid use during pregnancy in Europe, Canada, and Australia is around 5%.[22]Bateman BT, Hernandez-Diaz S, Straub L, et al. Association of first trimester prescription opioid use with congenital malformations in the offspring: population based cohort study. BMJ. 2021 Feb 10;372:n102.
https://www.bmj.com/content/372/bmj.n102.long
http://www.ncbi.nlm.nih.gov/pubmed/33568363?tool=bestpractice.com
Many people with opioid use disorder use needles to administer opioids, resulting in infectious complications, including hepatitis B and C and HIV.[23]Degenhardt L, Peacock A, Colledge S, et al. Global prevalence of injecting drug use and sociodemographic characteristics and prevalence of HIV, HBV, and HCV in people who inject drugs: a multistage systematic review. Lancet Glob Health. 2017 Dec;5(12):e1192-207.
Cdc.gov/bird-flu/site.htmL
http://www.ncbi.nlm.nih.gov/pubmed/29074409?tool=bestpractice.com