heroin, buprenorphine, naltrexone

Methadone maintenance treatment is the most commonly used substitution therapy for the treatment of heroin dependence. The methadone is typically swallowed as a syrup.

While its effects on the brain are similar to those of heroin, methadone lacks many of the negative side effects associated with heroin use. Because it is swallowed, the risks associated with injecting drug use are removed. When stabilised on methadone, a person is able to undertake usual life activities, including driving. Since the methadone is prescribed by a doctor, problems associated with controlling dosage and using the illegal market are less than with heroin.

Methadone can be injected, and overdose is still possible. However, the evidence suggests that methadone maintenance treatment reduces the risk of death to one-third of the risk for users not in treatment. It also reduces heroin use, other criminal activity associated with the illegal market, and obstetric and foetal complications, while leading to an increase in users' legitimate earnings.

Because methadone is not effective for all heroin users, other drug therapies have been developed, including buprenorphine and naltrexone.

Heroin treatment

The most effective treatments for heroin dependence are substitution therapies. These involve substituting other less harmful drugs for heroin, usually on a long-term basis. Doses must be high enough to prevent withdrawal symptoms.

People in treatment also need good psychological and social support, addressing motivation and coping skills, if they are to succeed in giving upheroin.

Heroin, opiates and opioids

The term opiate is used to describe naturally occurring drugs obtained from opium poppies. Opium is the resin taken from the poppies, from which the opiates morphine and codeine are extracted.

Opiates act on nerve cells in the brain called opioid receptors to depress the activity of the nervous system and act as very effective pain killers.

Heroin is not derived directly from the opium poppy—it is manufactured from morphine. It is called an opioid agonist because it activates the brain in the same way as the opiates.

Methadone is a synthetic opioid agonist that affects the brain in the same way as morphine and heroin.

While the opioid agonists activate the opioid receptors, naltrexone acts to block these receptors (so drugs like heroin cannot activate them); it is an opioid antagonist .

Buprenorphine is a mixed opioid agonist-antagonist. It activates the opioid receptors to a lesser extent than heroin, methadone and morphine, but it acts at the same time to block the receptors, preventing heroin and other opioids from having much effect.