There is an interesting article on the history of heroin maintenance programs [See Here: Free Junk for Junkies] Basically, maintenance programs were the norm before all this drug war nonsense started. Before the criminalization of drugs, mid 1800's to early 1900's, doctor's routinely prescribed heroin and morphine to addicted patients...of course these maintenance programs worked perfectly well and most addicts were seen as perfectly respectable members of society, just like any other person most of them worked, made money and were fully functioning. Aside from the benefits to the individual addict, these maintenance programs of course didn't have any of the negative social repercussions that the criminalization of drugs did...it's quite predictable what happened after the prohibition of drugs went into effect and the maintenance programs ended.

An excerpt from the article:

In the 19th century, all drugs were legal and readily available. Drug addiction was not uncommon, though it was rarely the result of the recreational use of drugs. Rather it was usually caused by the excessive use of opium and morphine (and later heroin) in medical care. Self-prescribing doctors often became hooked. So did soldiers: After the Civil War, Americans called addiction "the army disease."

Just as the origins of addiction were different, so were the consequences. Because drugs were legal, they were cheap. An addict didn't have to bankrupt himself or enter a criminal subculture to maintain a habit and so addiction rarely led to a life in ghettoes and gutters. On the contrary, the Victorian stereotype of an addict was a bored, middle-class housewife.

Addiction itself was generally not considered shameful. What mattered was how the addict behaved. The addict who reveled in selfish, destructive, pleasure-seeking excess was contemptible. But the addict who worked hard and did all that was expected of a good bourgeois citizen was just as respectable as any other person.

These attitudes shaped how doctors treated addiction. Much research into breaking addiction was done and many doctors struggled to get their patients off drugs. But doctors also knew that a regular, low-level dose of morphine or heroin could keep away the sickness of withdrawal with little or no impairment of the patient's ability to lead a productive life. When quitting proved too demanding, doctors gave their patients maintenance doses.

From the beginning of the 20th century until the 1920s, social reformers in many countries scored a series of victories in their drive to criminally prohibit alcohol, opium, morphine, heroin, prostitution, pornography, gambling, lewd theatre performances and dancehalls.

The anti-vice crusade was very much a moral reform movement and along with changes in the law it sought changes in attitude...At first, doctors took little notice of the new moralism, assuming that no matter what the legal status of drugs their freedom to practice as they saw fit would be untouched; some physicians were even leaders in the prohibition movement.

But the reformers, and the criminal prohibition they enacted, succeeded in changing how drugs were seen. Drugs were no longer a health issue. They were a criminal matter. Law enforcement officials became key figures in drug policy and the police naturally drew a bright line between the legal and illegal. Drugs were simply contraband, criminal, evil. The context of a drug's use was irrelevant because the law doesn't make exceptions for evil. Illegal drugs must simply be wiped out.

In 1916, the United States Justice Department declared that maintenance was not a legitimate medical practice and therefore was illegal under the Harrison Narcotics Act of 1914. Doctors were furious and loudly protested, but to no avail.

By 1920, as historian David Musto wrote in The American Disease, "advocacy of maintenance was repressed as sternly as socialism." Doctors and pharmacists were arrested. Clinics doing the same work that the Swiss and Dutch would experiment with 70 years later, with the same results, were raided and shut down. A total ban on heroin in medicine followed.

Desperate addicts looked elsewhere for drugs and a criminal black market in narcotics blossomed. The criminal dealer "finds himself in clover," lamented the Illinois Medical Journal in 1926, while "the doctor who needs narcotics used in reason to cure and allay human misery finds himself in a pit of trouble." Within a decade of the criminalization of drugs, maintenance had vanished from the United States and was soon forgotten.

Sorry that was so long, but there's even more interesting history in the article...including discussion about current maintenance programs and the predictable success that they are having.