January 19, 2012

Methadone-Related Emergency Department Visits Involving Nonmedical Use

Methadone is a long-acting opioid (synthetic opiate)¹ that has been used for the past five decades in narcotic treatment programs to treat addiction to heroin, morphine, and other opioid drugs.² It is used as replacement therapy for patients addicted to opiates by reducing craving and withdrawal symptoms. More recently, methadone has been used to treat chronic pain, resulting in a 1,000 percent increase in retail methadone distribution between 1997 and 2006.³ As methadone has gained popularity as a narcotic pain reliever, researchers have identified a concurrent rise in the number of fatalities associated with methadone use. Specifically, although methadone represents less than 5 percent of opioid prescriptions dispensed, one third of opioid-related deaths in the United States from 1999 to 2004 involved methadone.⁴

The nonmedical use of methadone is of particular concern because methadone remains active in the body even after its therapeutic effects (such as pain relief) have subsided.⁵ Thus, whether a patient seeks relief from breakthrough pain, a chronic opiate user seeks to stave off withdrawal, or someone seeks to get high or augment the effect of other drugs, individuals may mistakenly think that the dose of methadone has "worn off" and then use other medications, alcohol, or illicit drugs. This may create a dangerous mix of substances that can cause major medical complications, such as depressed respiration, irregular heartbeat, or death.

The Drug Abuse Warning Network (DAWN) is a public health surveillance system that monitors drug-related emergency department (ED) visits in the United States and can be used to track methadone-related ED visits involving nonmedical use. To be a DAWN case, an ED visit must involve a drug, either as the direct cause of the visit or as a contributing factor. Nonmedical use of drugs includes: (1) taking more than the prescribed dose, (2) taking a drug that was prescribed for another individual, (3) being deliberately poisoned with a drug by another person, and (4) documented misuse or abuse of a drug. Nonmedical use visits may include the use of methadone alone or in combination with illicit drugs or alcohol; moreover, DAWN is not able to differentiate between methadone used to treat opioid dependence and methadone intended for pain relief. This issue of The DAWN Report highlights characteristics of methadone-related ED visits involving nonmedical use in 2009 as well as recent trends.

Since 2004, the majority of methadone-related ED visits involved nonmedical use. Specifically in 2009, there were 91,360 ED visits involving methadone; of these, 69 percent were nonmedical use visits. The number of methadone-related ED visits involving nonmedical use rose 71 percent between 2004 and 2009 (from 36,806 to 63,031 visits) overall, but has leveled off in recent years (Figure 1).

Figure 1. Trends in Methadone-Related Emergency Department (ED) Visits Involving Nonmedical Use, by Gender*: 2004 to 2009

Among females, methadone-related ED visits involving nonmedical use doubled from 14,376 visits in 2004 to 29,402 visits in 2009 (Figure 1). During the same time period, visits among males increased 50 percent from 22,424 to 33,612 visits. In 2009, 53 percent of visits were made by males.

Visits made by patients aged 25 to 54 accounted for most (70 percent) of the methadone-related ED visits involving nonmedical use. More specifically, 28 percent were made by patients aged 25 to 34; 23 percent were made by patients aged 35 to 44; and 19 percent were made by patients aged 45 to 54 (Figure 2).

Figure 2. Methadone-Related Emergency Department (ED) Visits Involving Nonmedical Use, by Age*: 2009

Nearly two thirds (65 percent) of methadone-related ED visits involving nonmedical use also involved another drug. Although there was an average of two drugs per visit, a substantial portion of visits (19 percent) involved methadone combined with three or more other drugs (Table 1).

In 2009, pharmaceuticals were present in about half (53 percent) of methadone-related ED visits involving nonmedical use; in one third (33 percent) of visits, pharmaceuticals were the only other type of drug involved (Figure 3). The pharmaceuticals most commonly combined with methadone were drugs that treat anxiety and insomnia (e.g., sedatives and sleeping pills) (involved in 29 percent of visits) and other narcotic pain relievers (involved in 28 percent of visits) (Table 1).

Illicit drugs were involved in one in four (25 percent) nonmedical use visits involving methadone (15,990 visits) (Table 1). Many of these visits also involved other pharmaceuticals and/or alcohol (Figure 3). Of the methadone and illicit drug combinations, marijuana (6,718 visits), heroin (5,741 visits), and cocaine (5,271 visits) were the most common (Table 1). Alcohol was involved in 10 percent of visits, often along with other pharmaceuticals and/or illicit drugs (Figure 3).

Figure 3. Types of Drug Combinations in Methadone-Related Emergency Department (ED) Visits Involving Nonmedical Use: 2009

Methadone is a safe drug when used appropriately and monitored by medical staff. Although it has been historically used to treat opiate addiction, methadone has become a commonly used pain reliever in recent years. As its popularity has increased among prescribing physicians, its availability—and therefore, its potential for diversion and misuse—has also increased. Consequently, this has made methadone more accessible, even for those who do not have a prescription.

In this report, approximately half of the methadone-related ED visits involving nonmedical use involved another pharmaceutical. However, combining methadone with other drugs can be risky, especially if those drugs mimic the sedative effects of methadone. The most common pharmaceutical combinations involved drugs that are known to be dangerous when combined with methadone (e.g., other narcotic pain relievers and drugs that treat anxiety or sleep disorders). Such drug combinations can result in depression of the respiratory and/or central nervous systems, which may result in a range of symptoms from shallow breathing, excessive drowsiness, or abnormal heart beat to loss of consciousness and death.

Patients who are prescribed methadone should be educated about its appropriate use and the risks of misuse. These discussions should cover methadone's long-lasting effects and the dangers of combining it with other drugs. Education may prevent patients from taking more frequent or larger doses of methadone when they think the methadone has worn off and/or from consuming other drugs, including alcohol, in combination with methadone. Patients should also be instructed to store their methadone securely and not share it with others.⁶ Family members and friends of methadone patients can be educated to recognize signs of an overdose (e.g., shallow breathing, weak heartbeat, confusion) and be urged to contact emergency services if they suspect an overdose.

In addition to educating themselves about appropriate methadone dosing and possible drug interactions, physicians who intend to prescribe methadone for pain management should also take steps to prevent nonmedical use of methadone by their patients. This includes first screening patients for substance abuse and mental health problems, monitoring patients' use, and prescribing only enough for the length of time that the pain is expected to last.⁶ Resource materials are readily available online to help guide medical personnel when methadone is under consideration (e.g., http://pain-topics.org/pdf/Methadone-Drug_Intx_2006.pdf).^2,7

In this report, nearly one third of the nonmedical use ED visits involved methadone only, underscoring the need for broader public awareness of the dangers of methadone misuse. Public health campaigns targeting methadone safety have been developed by the Substance Abuse and Mental Health Services Administration, including brochures, posters, fact sheets, and media materials.⁸ These materials may be accessed via http://www.dpt.samhsa.gov/methadonesafety/index.aspx.