Opioid Toxicity

The term "opiate" refers to natural compounds derived from the base of the poppy flower, such as opium, morphine, diacetylmorphine (heroin), and codeine. In contrast, opioids are synthesized through chemical processes and include methadone, oxycodone, and fentanyl. Opiates have been used since antiquity to relieve pain and induce euphoria. Today, these agents remain a widely used option for pain relief. Opiates have been formally approved for analgesia for nearly 70 years and have long been assumed to be relatively safe and nonaddictive when used for chronic pain. In 1995, Dr. James Campbell addressed the American Pain Society, advocating for the evaluation of pain as a vital sign. His intentions were well-meaning, motivated by concerns about the undertreatment of pain. However, over the past 2 decades, numerous reports have raised alarms about the safety of these drugs. Cases of overdose and opiate toxicity are reported regularly across major cities in the United States. Particularly concerning is the dramatic increase in opiate prescriptions over the same period. This widespread prescribing by healthcare providers has contributed to an epidemic of overdoses outside the healthcare setting. Consequently, practicing healthcare professionals should recognize opiate toxicity in patients who present as lethargic or unresponsive without an apparent cause. (CDC, 2017) Data released by the Drug Enforcement Administration (DEA) and the Centers for Disease Control and Prevention (CDC) indicate that, from 2001 through 2010, the rates of opiate diversion, opiate prescriptions, and opiate-related deaths exponentially increased in the United States. These rates plateaued from 2011 through 2013 but spiked again between 2013 and 2014. Experts in pain management believe that the high number of opiate overdoses is likely unintentional, as patients may have been attempting to manage unrelenting pain. (CDC, 2016) Prescriptions for opioid-containing medications quadrupled between 1999 and 2010, paralleling a 4-fold increase in overdose deaths due to opioids. The majority of opioid-related deaths are attributed to the use of heroin and synthetic opioids other than methadone. The issue of poorly treated pain has led medical professionals to use various short- and long-acting opiates. While this approach has significantly improved pain relief, some patients often fail to adhere to proper dosing. When patients increase the dose or duration of opioid use, toxicity becomes a potential complication. Although the annual rates of transition are low, toxicity often occurs when individuals move from the nonmedical use of prescription opioids to heroin. Opioid overdose occurs when excessive unopposed stimulation of the opiate pathway leads to decreased respiratory effort and, potentially, death. The frequency of opioid overdoses is rapidly increasing. Drug overdose is now the leading cause of accidental death in the United States, with opioids being the most common culprit. According to the CDC, more than 1,000 emergency department visits reported daily are related to opioid misuse, and about 91 opioid overdose deaths are documented every day. Heroin, priced at about $2 per bag, is up to 10 times cheaper and more readily available than prescription opioid medications purchased on the street, which average around a dollar per milligram. Additionally, heroin is increasingly being mixed with fentanyl and other synthetic opioid compounds, resulting in variable opioid potency and a higher risk of overdose. Nonpharmaceutical or "street" opioids are often contaminated with other substances. To increase profits, sellers frequently add additional agents to the formula without informing the end user. These additives are pharmacologically active in many cases. Heroin was adulterated with scopolamine 2 decades ago in New York City, causing severe anticholinergic toxicity. Cocaine adulteration is also prevalent. Most states have established prescription drug monitoring programs (PDMPs) to counter the liberal prescribing of opiates by healthcare workers. In many states, healthcare professionals must consult the state’s online drug database to determine which analgesic drugs may be prescribed to patients. Such state-enacted legislation aims to prevent mass opiate prescriptions by healthcare workers and to help stop the diversion of legitimate opiate prescriptions. (DEA, 2016) Results are mixed, but research suggests that opioid databases have reduced opioid prescribing. Additionally, with the assistance of the DEA, statewide registries of controlled substances now help healthcare providers track usage patterns among patients to identify people at high risk for opiate diversion or abuse. While the availability of opiates contributes to opioid addiction, no evidence has yet demonstrated a direct link between opiate abuse and the legitimate use of these drugs for pain. (DEA, 2016)