Even if you can get through the first few days of opiate withdrawal — which former addicts describe as the worst flu ever — staying clean takes months and years of hard work and dedication, recovery experts say.

For the past four decades, methadone has been an option for addicts struggling to detox.

The drug is often given in liquid form and dispensed only by federally licensed clinics; doctors are not allowed to prescribe it.

In low doses, methadone is also used to treat chronic pain. But those who are already addicted to heroin or prescription pain pills take much higher doses of the drug to combat addiction. Methadone fills up the user’s brain receptors, making him or her unable to feel effects from other opioids, while also helping with the negative effects of withdrawal.

Compared to heroin and other shorter-acting opioids, which require addicts to seek several fixes a day, methadone can give the user up to 24 hours free from withdrawal symptoms.

It blunts the “peaks and valleys of craving,” according to Dr. Seddon R. Savage, an anesthesiology professor at Dartmouth College and the leader of the Dartmouth Center on Addiction, Recovery and Education.

Methadone treatment is, literally, substituting one drug for another. But health officials say that’s not necessarily a bad thing.

“It’s possible to do well when you treat appropriately,” said Dr. Nels A. Kloster, an addiction medicine specialist in Brattleboro and the medical director of the methadone clinic there, which is owned by a company called Habit OPCO.

Treating appropriately means a lot of counseling in addition to methadone, health experts say. Brattleboro’s Habit OPCO clinic sometimes partners with the Brattleboro Retreat, a local counseling and recovery center.

Kloster and Habit OPCO clinic counselor Barbara Vitalis disagree with methadone’s detractors, who say it’s just another drug on which patients get hooked.

They have treated people who they say have needed to stay on the drug for years; decades, even. But they also say they’ve seen patients who have been able to successfully taper themselves off methadone.

“We’re not the ones getting them high,” Vitalis said. “They go and work all day, whereas when they were using drugs all day, they couldn’t work. It beats putting a drug in your arm, and it’s controlled.”

Methadone clinics

Methadone needs to be taken daily to be effective, which means clients travel to clinics every day, some covering long distances.

After three months in treatment and demonstrating good behavior, clients are allowed one take-home dose of methadone per week, according to New Hampshire state standards. If they continue demonstrating good behavior, they get another take-home dose every three months. New Hampshire rules cap the number of take-home doses per week at six.

Clients are also supposed to be screened for drugs including other opiates, amphetamines, cocaine, benzodiazepines, barbiturates and marijuana, according to state standards. Clients should undergo weekly drug screens during the first three months in treatment, and one every month after that.

In New Hampshire, long-term detoxification means methadone clinics administer the drug “in a way for a client to reach a drug-free state and to make progress in rehabilitation within a period of between 90 days and 180 days,” according to state standards.

Advocates don’t suggest putting time limits on treatment, though.

A misconception about treatment is that a user should be completely drug free by the end of it, addiction experts like Savage say. If they are productive members of society while on methadone, they should stay that way.

“Recovery is a balanced quality of life, it’s not about whether you’re abstinent from drugs,” Savage said.