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CE ARTICLE Overview Death from poisoning kills many people in the United States every year, and unintentional poisoning is one of the leading causes of death by injury. In 2010, 42,837 persons died as the result of poisoning.1 Of these deaths, about 77% (33,041) were unintentional, 15.5% (6,599) were the result of suicide attempts, and 7.5% (3,197) were of undetermined intent. To put it into perspective, unintentional poisoning was second only to motor vehicle crashes (MVC) (33,687) as the most frequent cause of death from unintentional injury for all ages in 2010. Among persons 25–64, unintentional poisoning was responsible for more deaths than MVCs.1 EMS education puts a focus on trauma and injuries, but arguably less of a focus on poisoning. With poisoning being such a major contributor to unintentional deaths in the U.S., it is important that EMTs and paramedics are familiar with the most common causes of unintentional poisoning and their treatment. This month's CE article focuses on the most common cause of unintentional death by poisoning, prescription painkiller drugs. Data collected from 1999–2010 show the incidence of death from prescription painkillers has grown linearly with the sales of these medications. The Basics A poison is any substance that is harmful to your body if ingested, inhaled, absorbed or injected. A poisoning occurs when exposure to a substance adversely affects the function of body systems. If a large enough quantity is administered, any substance has the potential to be a poison, including seemingly harmless and even essential substances such as vitamins. Poisonings can be classifed as intentional or unintentional. An intentional poisoning occurs when a person administers a substance with an intent to cause harm to themselves or another. An unintentional poisoning occurs when a person taking or administering a substance lacks intent to cause harm but still provides or consumes a dangerous quantity. A painkiller is any medication that provides analgesia, or relief from pain. 58 JUNE 2013 | EMSWORLD.com Table 1: Common Opioid Prescription Painkillers GENERIC NAME BRAND NAME Buprenorphine Buprenex, Suboxone, Subutex Butorphanol Stadol Codeine Fioricet with codeine, Tylenol with codeine Dihydrocodeine Panlor, Paracodin Fentanyl Duragesic patch Hydrocodone Lorcet, Lortab, Norco, Vicodin, Vicoprofen Hydromorphone Dilaudid, Hydromorph Contin, Palladone Meperidine Demerol Methadone Amidone, Dolophine, Methadose Morphine sulfate Avinza, Kadian, MS-Contin, Oramorph, Roxanol Nalbuphine Nubain Oxycodone Endocet, OxyContin, Percocet, Percodan, Roxicodone, Tylox Oxymorphone Numorphan, Opana Pentazocine Talwin Propoxyphene Darvon, Darvocet Tramadol Ultracet, Ultram The analgesics most frequently involved in unintentional death by poisoning belong to the family of drugs known as opioids. An opioid is a chemical that binds to opioid receptors in the central and peripheral nervous systems as well as the gastrointestinal tract. When they bind with opioid receptors in the brain (central nervous system), opioids produce decreased perception of and reaction to pain, as well as increased pain tolerance. Opioids are used to treat acute pain (such as postoperative pain or pain from injury), as well as chronic pain associated with conditions such as back/spinal injury, arthritis and cancer. For examples of commonly prescribed opioid medications, see Table 1. Standard oral preparations of opioids are readily absorbed by the gastrointestinal tract, achieving peak blood levels about 30–60 minutes after ingestion. Sustained-release formulas take longer to achieve peak blood levels. Most ingested opioids undergo first-pass metabolism by the liver, meaning they will be metabolized in the liver prior to entering the systemic circulation. As a result, the bioavailability of ingested opioids is reduced as much as 80% after ingestion, and at equal doses most opioids will be much more potent when administered intravenously (parenterally) than by ingestion or transdermal patches. The Growing Problem In 2009, 91% of unintentional poisoning deaths were caused by prescription medications. Opioid pain medications and benzodiazepines were most commonly involved. Prescription painkiller overdoses were responsible for more than 15,500 deaths in 2009, more than the total for cocaine and heroin combined.2 This number is almost four times greater than the 4,000 people killed by prescription painkiller medications in 1999. While all prescription painkillers have contributed to the increase in overdose deaths over the last decade, methadone has played a central role. More than 30% of prescription painkiller deaths involve it, even though only 2% of painkiller prescriptions are for it.2 More than 12 million Americans reported using prescription painkillers for nonmedical reasons in 2012.3 Where do these drugs come from? While about 17.3% of those who misuse prescription painkillers do so with their own medications prescribed to them, more than three-fourths of prescription painkillers involved in overdoses come from prescriptions diverted to persons without them.3 Diversion is a term used by the Drug Enforcement Administration to describe prescription medications that are used for other than their original purposes. The majority of misused prescription painkillers (55%) are