Methadone

Approved: 1947

How it works: Fills the same brain receptors that drugs like heroin and oxycontin activate, but more slowly. Eliminates withdrawal symptoms and cravings, and blocks the euphoric effects of other opioids.

Effectiveness: Research shows that patients on methadone are less likely to use other opioids, more likely to stay in treatment, and less likely to overdose than patients whose treatment did not include medication.

How to get it: Requires daily visits to a methadone clinic, making access difficult for people who don’t live near one.

Risks and abuses: Overdose can occur, but most such cases involve other drugs, particularly tranquilizers or alcohol. Methadone prevents far more overdoses than it causes. Typically provided as a liquid consumed at the clinic, making diversion difficult. Withdrawal from methadone can be difficult and takes several months.

Buprenorphine (Suboxone, Subutex, etc.)

Approved: 2002

How it works: Partially fills the brain’s opioid receptors, displacing other opioids. It reduces cravings and withdrawal symptoms without inducing euphoria, and blocks the effects of other opioids.

Effectiveness: Patients taking adequate doses (usually 16 milligrams a day) are twice as likely to stay in treatment as patients without medication, according to one study. Extensive research shows they are also less likely to use other opioids and to overdose.

How to get it: Physicians may prescribe buprenorphine, provided they have completed an eight-hour training course. Nurse practitioners and physician assistants can also prescribe, but they must first complete a 24-hour course.

Risks and abuses: It is nearly impossible to overdose on buprenorphine alone. When injected or combined with tranquilizers or alcohol, it can be fatal, but buprenorphine is generally safer than methadone and other opioids. Can be sold on the street, as addicts seek relief from withdrawal symptoms or mix it with other substances for a low-grade high.

injectable naltrexone (Vivitrol)

Approved: 2010

How it works: Blocks off opioid receptors. Instead of easing withdrawal symptoms and cravings, it prevents any opioid from producing euphoria. The long-acting injectable form, Vivitrol, keeps this blockage in place for three or four weeks.

Effectiveness: As a newer drug, Vivitrol has less data to back its effectiveness, but a few studies have shown it can help keep people in treatment and prevent relapse. Patients must fully withdraw from all opioids before they can take it, an obstacle for many.

How to get it: Naltrexone is not a controlled substance. But patients must visit a medical professional to have the shot administered into the buttock.

Risks and abuses: Naltrexone has no euphoric effects and no street value. Patients who skip their injection and relapse are at high risk of overdose because their tolerance is low.

Felice J. Freyer

Felice J. Freyer can be reached at felice.freyer@globe.com. Follow her on Twitter @felicejfreyer