(CNN) Here's a look at the opioid crisis.
Experts say the United States is in the throes of an opioid epidemic. An estimated 8.9 million Americans aged 12 and older misused opioids in 2022, including 8.5 million prescription pain reliever abusers and 1 million heroin users.
Opioids are drugs formulated to replicate the pain-reducing properties of opium. Prescription painkillers like morphine, oxycodone and hydrocodone are opioids. Illegal drugs like heroin and illicitly made fentanyl are also opioids. The word "opioid" is derived from the word "opium."
Overdose deaths have been on the rise for years in the United States, but surged amid the Covid-19 pandemic: Annual deaths were nearly 50% higher in 2021 than in 2019, CDC data shows. Data on overdose deaths.
Prescription opioid volumes peaked in 2011, with the equivalent of 240 billion milligrams of morphine prescribed, according to the market research firm, IQVIA Institute for Human Data Science.
Alabama, Arkansas, Louisiana and Tennessee had the highest opioid dispensing rates in 2020.
Opioids such as morphine and codeine are naturally derived from opium poppy plants more commonly grown in Asia, Central America and South America. Heroin is an illegal drug synthesized from morphine.
Hydrocodone and oxycodone are semi-synthetic opioids, manufactured in labs with natural and synthetic ingredients.
Fentanyl is a fully synthetic opioid, originally developed as a powerful anesthetic for surgery. It is also administered to alleviate severe pain associated with terminal illnesses like cancer. The drug is up to 100 times more powerful than morphine. Just a small dose can be deadly. Illicitly produced fentanyl has been a driving factor in the number of overdose deaths in recent years.
Methadone is another fully synthetic opioid. It is commonly dispensed to recovering heroin addicts to relieve the symptoms of withdrawal.
Opioids bind to receptors in the brain and spinal cord, disrupting pain signals. They also activate the reward areas of the brain by releasing the hormone dopamine, creating a feeling of euphoria or a "high."
Opioid use disorder is the clinical term for opioid addiction or abuse.
People who become dependent on opioids may experience withdrawal symptoms when they stop using the medication. Dependence is often coupled with tolerance, meaning that users need to take increasingly larger doses for the same effect.
A drug called naloxone, available as an injection or a nasal spray, is used as a treatment for overdoses. It blocks or reverses the effects of opioids and is often carried by first responders.
The 21st Century Cures Act, passed in 2016, allocated $1 billion over two years in opioid crisis grants to states, providing funding for expanded treatment and prevention programs. In April 2017, Health and Human Services Secretary Tom Price announced the distribution of the first round of $485 million in grants to all 50 states and US territories.
In August 2017, Attorney General Jeff Sessions announced the launch of an Opioid Fraud and Abuse Detection Unit within the Department of Justice. The unit's mission is to prosecute individuals who commit opioid-related health care fraud. The DOJ is also appointing US attorneys who will specialize in opioid health care fraud cases as part of a three-year pilot program in 12 jurisdictions nationwide.
On October 24, 2018, President Donald Trump signed opioid legislation into law. The SUPPORT for Patients and Communities Act includes provisions aimed at promoting research to find new drugs for pain management that will not be addictive. It also expands access to treatment for substance use disorders for Medicaid patients.
State legislatures have also introduced measures to regulate pain clinics and limit the quantity of opioids that doctors can dispense.
1861-1865 - During the Civil War, medics use morphine as a battlefield anesthetic. Many soldiers become dependent on the drug.
1898 - Heroin is first produced commercially by the Bayer Company. At the time, heroin is believed to be less habit-forming than morphine, so it is dispensed to individuals who are addicted to morphine.
1914 - Congress passes the Harrison Narcotics Act, which requires that doctors write prescriptions for narcotic drugs like opioids and cocaine. Importers, manufacturers and distributors of narcotics must register with the Treasury Department and pay taxes on products
1924 - The Anti-Heroin Act bans the production and sale of heroin in the United States.
1970 - The Controlled Substances Act becomes law. It creates groupings (or schedules) of drugs based on the potential for abuse. Heroin is a Schedule I drug while morphine, fentanyl, oxycodone (Percocet) and methadone are Schedule II. Hydrocodone (Vicodin) is originally a Schedule III medication. It is later recategorized as a Schedule II drug.
January 10, 1980 - A letter titled "Addiction Rare in Patients Treated with Narcotics" is published in the New England Journal of Medicine. It looks at incidences of painkiller addiction in a very specific population of hospitalized patients who were closely monitored. It becomes widely cited as proof that narcotics are a safe treatment for chronic pain.
1995 - OxyContin, a long-acting version of oxycodone that slowly releases the drug over 12 hours, is introduced and aggressively marketed as a safer pain pill by manufacturer, Purdue Pharma.
May 10, 2007 - Purdue Pharma pleads guilty for misleadingly advertising OxyContin as safer and less addictive than other opioids. The company and three executives are charged with "misleading and defrauding physicians and consumers." Purdue and the executives agree to pay $634.5 million in criminal and civil fines.
2010 - FDA approves an "abuse-deterrent" formulation of OxyContin, to help curb abuse. However, people still find ways to abuse it.
May 20, 2015 - The DEA announces that it has arrested 280 people, including 22 doctors and pharmacists, after a 15-month sting operation centered on health care providers who dispense large amounts of opioids. The sting, dubbed Operation Pilluted, is the largest prescription drug bust in the history of the DEA.
March 18, 2016 - The CDC publishes guidelines for prescribing opioids for patients with chronic pain. Recommendations include prescribing over-the-counter pain relievers like acetaminophen and ibuprofen in lieu of opioids. Doctors are encouraged to promote exercise and behavioral treatments to help patients cope with pain.
March 29, 2017 - Trump signs an executive order calling for the establishment of the President's Commission on Combating Drug Addiction and the Opioid Crisis. New Jersey Governor Chris Christie is selected as the chairman of the group, with Trump's son-in-law, Jared Kushner, as an adviser.
July 31, 2017 - After a delay, the White House panel examining the nation's opioid epidemic releases its interim report, asking Trump to declare a national public health emergency to combat the ongoing crisis
September 22, 2017 - The pharmacy chain CVS announces that it will implement new restrictions on filling prescriptions for opioids, dispensing a limited seven-day supply to patients who are new to pain therapy.
November 1, 2017 - The opioid commission releases its final report. Its 56 recommendations include a proposal to establish nationwide drug courts that would place opioid addicts in treatment facilities rather than prison.
February 9, 2018 - A budget agreement signed by Trump authorizes $6 billion for opioid programs, with $3 billion allocated for 2018 and $3 billion allocated for 2019.
February 27, 2018 - Sessions announces a new opioid initiative: The Prescription Interdiction & Litigation (PIL) Task Force. The mission of the task force is to support local jurisdictions that have filed lawsuits against prescription drugmakers and distributors.
March 19, 2018 - The Trump administration outlines an initiative to stop opioid abuse. The three areas of concentration are law enforcement and interdiction; prevention and education via an ad campaign; and job-seeking assistance for individuals fighting addiction.
April 9, 2018 - The US surgeon general issues an advisory recommending that Americans carry the opioid overdose-reversing drug, naloxone. A surgeon general advisory is a rarely used tool to convey an urgent message. The last advisory issued by the surgeon general, more than a decade ago, focused on drinking during pregnancy.
May 1, 2018 - The Journal of the American Medical Association publishes a study that finds synthetic opioids like fentanyl caused about 46% of opioid deaths in 2016. That's a three-fold increase compared with 2010, when synthetic opioids were involved in about 14% of opioid overdose deaths. It's the first time that synthetic opioids surpassed prescription opioids and heroin as the primary cause of overdose fatalities.
May 30, 2018 - The journal Medical Care publishes a study that estimates the cost of medical care and substance abuse treatment for opioid addiction was $78.5 billion in 2013.
June 7, 2018 - The White House announces a new multimillion dollar public awareness advertising campaign to combat opioid addiction. The first four ads of the campaign are all based on true stories illustrating the extreme lengths young adults have gone to obtain the powerful drugs.
December 12, 2018 - According to the National Center for Health Statistics, fentanyl is now the most commonly used drug involved in drug overdoses. The rate of drug overdoses involving the synthetic opioid skyrocketed by about 113% each year from 2013 through 2016.
January 14, 2019 - The National Safety Council finds that, for the first time on record, the odds of dying from an opioid overdose in the United States are now greater than those of dying in a vehicle crash.
March 26, 2019 - Purdue Pharma agrees to pay a $270 million settlement to settle a historic lawsuit brought by the Oklahoma attorney general. The settlement will be used to fund addiction research and help cities and counties with the opioid crisis.
July 17, 2019 - The CDC releases preliminary data showing a 5.1% decline in drug overdoses during 2018. If the preliminary number is accurate, it would mark the first annual drop in overdose deaths in more than two decades.
August 26, 2019 - Oklahoma wins its case against Johnson & Johnson in the first major opioid lawsuit trial to be held in the United States. Cleveland County District Judge Thad Balkman orders Johnson & Johnson to pay $572 million for its role in the state's opioid crisis. The penalty is later reduced to $465 million, due to a mathematical error made when calculating the judgment. In November 2021, the Oklahoma Supreme Court reverses the decision.
September 15, 2019 - Purdue files for bankruptcy as part of a $10 billion agreement to settle opioid lawsuits. According to a statement from the chair of Purdue's board of directors, the money will be allocated to communities nationwide struggling to address the crisis.
September 30, 2019 - The FDA and DEA announce that they sent warnings to four online networks, operating a total of 10 websites, which the agencies said are illegally marketing unapproved and misbranded versions of opioid medicines, including tramadol.
February 25, 2020 - Mallinckrodt, a large opioid manufacturer, reaches a settlement agreement in principle worth $1.6 billion. Mallinckrodt says the proposed deal will resolve all opioid-related claims against the company and its subsidiaries if it moves forward. Plaintiffs would receive payments over an eight-year period to cover the costs of opioid-addition treatments and other needs.
October 21, 2020 - The Justice Department announces that Purdue Pharma, the maker of OxyContin, has agreed to plead guilty to three federal criminal charges for its role in creating the nation's opioid crisis. They agree to pay more than $8 billion and close down the company. The money will go to opioid treatment and abatement programs. The Justice Department also reached a separate $225 million civil settlement with the former owners of Purdue Pharma, the Sackler family. In November 2020, Purdue Pharma board chairman Steve Miller formally pleads guilty on behalf of the company.
March 15, 2021 - According to court documents, Purdue files a restructuring plan to dissolve itself and establish a new company dedicated to programs designed to combat the opioid crisis. As part of the proposed plan, the Sackler family agrees to pay an additional $4.2 billion over the next nine years to resolve various civil claims.
September 1, 2021 - In federal bankruptcy court, Judge Robert Drain rules that Purdue Pharma will be dissolved. The settlement agreement resolves all civil litigation against the Sackler family members, Purdue Pharma and other related parties and entities, and awards them broad legal protection against future civil litigation. The Sacklers will relinquish control of family foundations with over $175 million in assets to the trustees of a National Opioid Abatement Trust. On December 16, 2021, a federal judge overturns the settlement.
February 25, 2022 - Johnson & Johnson and the three largest US drug distributors -- McKesson Corp, Cardinal Health Inc and AmerisourceBergen Corp -- finalize a $26 billion nationwide opioid settlement.
March 3, 2022 - The Sackler families reaches a settlement with a group of states the first week of March, according to court filings. The settlement, ordered through court-ordered mediation that began in January, requires the Sacklers to pay out as much as $6 billion to states, individual claimants and opioid crisis abatement, if approved by a federal bankruptcy court judge.
November 2, 2022 - CVS and Walgreens agree to pay a combined $10 billion, over 10 and 15 years, to settle lawsuits brought by states and local governments alleging the retailers mishandled prescriptions of opioid painkillers.
November 15, 2022 - Walmart agrees to the framework of a $3.1 billion settlement, which resolves allegations from multiple states' attorneys general that the company failed to regulate opioid prescriptions contributing to the nationwide opioid crisis.
August 10, 2023 - The US Supreme Court blocks Purdue Pharma from going forward with bankruptcy proceedings.
February 1, 2024 - New York Attorney General Letitia James announces that for the first time, an advertising company that worked on Purdue Pharma's OxyContin account has settled a lawsuit accusing it of falsely marketing opioids as safe. Publicis, a French marketing company, has agreed to pay $350 million within the next two months and will not take on any more opioid clients.