distribution of prescription opiates. Since the implementation of pill mill laws and drug monitoring programs in Florida, high-risk patients (defined as those who use both benzodiazepines and opioids, those who have been using high opioid doses for extended periods of time, or "opioid shoppers" that obtain their opioid painkillers from multiple sources) have shown significant reductions in opioid use. Trafficking As the number of opioid prescriptions rose, drug cartels began flooding the US with heroin from Mexico. For many opioid users, heroin was cheaper, more potent, and often easier to acquire than prescription medications. According to the CDC, tighter prescription policies by doctors did not necessarily lead to this increased heroin use. The main suppliers of heroin to the US have been Mexican transnational criminal organizations. From 2005 to 2009, Mexican heroin production increased by over 600%, from an estimated 8 metric tons in 2005 to 50 metric tons in 2009. Between 2010 and 2014, the amount seized at the border more than doubled. According to the Drug Enforcement Administration, smugglers and distributors "profit primarily by putting drugs on the street and have become crucial to the Mexican cartels." Illicit fentanyl is commonly made in Mexico and trafficked by cartels. North America's dominant trafficking group is Mexico's Sinaloa Cartel, which has been linked to 80 percent of the fentanyl seized in New York. See also Diseases of despair – including opioid overdose List of countries by prevalence of opiates use List of deaths from drug overdose and intoxication Opium in Iran, world's highest per capita rate of opiate addiction The Crime of the Century Dopesick United States drug overdose death rates and totals over time References Further reading Emily Witt, "A Blizzard of Prescriptions" (review of Beth Macy, Dopesick, Head of Zeus, 2019; Chris McGreal, American Overdose: The Opioid Tragedy in Three Acts, Faber, 2018; Sam Quinones, Dreamland: The True Tale of America's Opiate Epidemic, Bloomsbury, 2016), London Review of Books, vol. 41, no. 7 (April 4, 2019), pp. 23–26. "OxyContin['s] lamentable [market] success was owed to a confluence of factors particular to the US. They include, but are not limited to: the country's dysfunctional privatised healthcare system, which makes it possible for addicts to accumulate doctors willing to prescribe painkillers in a way they can't in the UK; a corrupt regulatory agency [the Food and Drug Administration] beholden to the [pharmaceutical] industry it was tasked with regulating; a punitive