Methadone Maintenance Treatment - NCBI Bookshelf - NCBI

6.1. INTRODUCTION

Methadone is an opioid, like heroin or opium. Methadone maintenance treatment has been used to treat opioid dependence since the 1950s.14 The opioid dependent patient takes a daily dose of methadone as a liquid or pill. This reduces their withdrawal symptoms and cravings for opioids.

Methadone is addictive, like other opioids. However, being on methadone is not the same as being dependent on illegal opioids such as heroin:

• It is safer for the patient to take methadone under medical supervision than it is to take heroin of unknown purity.
• Methadone is taken orally. Heroin is often injected, which can lead to HIV transmission if needles and syringes are shared.
• People are heroin dependent often spend most of their time trying to obtain and use heroin. This can involve criminal activity such as stealing. Patients in methadone do not need to do this. Instead, they can undertake productive activities such as education, employment and parenting.

Methadone has been included on the World Health Organization's List of Essential Medicines. This highlights its importance as a treatment for heroin dependence.

There has been a great deal of research on MMT. This research has found that

• MMT significantly reduces drug injecting;
• because it reduces drug injecting, MMT reduces HIV transmission;
• MMT significantly reduces the death rate associated with opioid dependence;
• MMT reduces criminal activity by opioid users; and
• Methadone doses of greater than 60mg are most effective.15

In closed settings, MMT should be available to patients who have been receiving MMT in the community and wish to continue this treatment in the closed setting, and patients with a history of opioid dependence who wish to commence MMT. Patients should receive MMT for the entire duration of their detention in the closed setting. This ensures the maximum benefits of the treatment are obtained.

Case study: The Hong Kong Methadone Maintenance Program

Hong Kong has had a methadone maintenance treatment program since 1972. The program was started in response to rising levels of drug use. More recently, the program has been crucial to controlling the HIV epidemic. Hong Kong methadone clinics have several important characteristics that make them easy for drug users to access:

Low cost of treatment – HK$1 (about 12 US cents) per clinic attendance

Open seven days per week and are open from early in the morning to late at night

Operate on a “low threshold” model – this means that there are few conditions that patients must meet to begin treatment

Non-judgemental approach that includes providing harm reduction information and condoms

Research conducted with patients of the Hong Kong methadone program has shown that patients who attend the clinic regularly show reduced levels of drug injecting and HIV risk behaviours. It has also been shown that patients receiving methadone doses of greater than 60mg per day were less likely to use or inject drugs than patients receiving doses of less than 60mg per day.

Rationale for MMT in closed settings

In countries where MMT is available in the community, it should also be available in prisons. This is in line with the public health approach to HIV prevention and the principle of equivalence of care.

MMT is provided to inmates in prisons in at least thirty countries, including Australia, Canada, Indonesia, Iran, and Spain. There are several compelling reasons for providing MMT to opioid dependent patients in closed settings:

Reducing risks associated with injecting drug use

MMT in closed settings reduces drug injecting by prisoners. In Australia, a trial of MMT in prison found that despite being in prison, over 80% of inmates starting methadone treatment had used heroin in the previous month; however, after four months of treatment, only 25% of prisoners were still using heroin.16 By reducing drug injecting, MMT reduces opportunities for HIV to be transmitted between prisoners.

Reducing risk of re-incarceration

Many drug users experience multiple episodes of detention in closed settings. However, patients who remain in MMT after leaving closed settings are less likely to return to closed settings than non-treated heroin users.17

Reducing the risk of relapse following release

People who leave closed settings often relapse to regular drug use within a few days or weeks of being released. Being in MMT in the closed setting and then continuing treatment in the community reduces the risk of relapse.

Case study: Methadone maintenance treatment in prison in Indonesia

Indonesia established a pilot methadone maintenance program in prison in 2005. The program was started as part of Indonesia's comprehensive HIV prevention strategy for prisons. Other components of the strategy include distributing condoms and bleach (for cleaning used needles and syringes) in prison and providing free antiretroviral treatment for HIV-positive prisoners.

Some of the patients in the methadone program are continuing treatment begun in the community, while others have started methadone treatment in prison. Patients who are HIV-positive receive free antiretroviral treatment in addition to methadone.

There are plans to expand the methadone maintenance program to other prisons in Indonesia. The success of this pilot program has demonstrated that it is feasible to introduce methadone maintenance treatment in resource-poor settings.

Required resources

Essential staff

Physicians

Only a medical doctor may prescribe methadone. A medical doctor should conduct the assessment on which the decision to prescribe methadone is based. Doctors also take part in treatment planning and treatment reviews.

Nurses

Nurses are required to conduct methadone dispensing and supervision of its consumption. Other roles for nurses in methadone maintenance treatment include:

• Taking part in treatment reviews and providing reports to clinic doctors
• Providing vaccinations (e.g. hepatitis A and B) and referring patients for infectious disease testing (e.g. HIV, hepatitis, sexually transmitted infections, tuberculosis)
• Attending to general health needs of patients, for example, dressing wounds and ulcers; assisting with general hygiene and infection control

Counsellors

Counsellors support medical staff of the treatment program by:

• Providing general counselling on issues of concern to patients
• Undertaking motivational interviewing with patients to increase motivation to reduce illicit drug use
• Providing pre- and post-test counselling for patients seeking testing for HIV or other infectious diseases

Other professionals

Although not essential, the following staff can also assist patients in methadone maintenance treatment:

Psychologists

Psychologists can assist patients suffering from co-morbid mental illnesses and psychiatric problems such as depression, anxiety or post-traumatic stress disorder.

Social or welfare workers

Social workers and welfare workers can provide general counselling and assist patients with practical concerns such as contacting their family or finding housing for when they leave the closed setting.

Community liaison officers

A community liaison officer is employed specifically to assist patients to transfer to community-based MMT programs on their release from the closed setting. This person may have skills or training in social or welfare work.

Facilities

Medical clinic

Methadone should be dispensed via a medical clinic within the closed setting. The clinic must be staffed and open to patients seven days per week. The clinic should be equipped with a dispensing pump or measuring cylinder for ensuring accurate methadone dosing, and should also maintain adequate supplies of basic first aid and resuscitation equipment.

Secure storage area

Methadone must be stored in a secure area within the medical clinic, for example, locked in a room or safe. It should not be obvious to patients that this is where methadone is stored.

Post-dosing supervision room

Following dosing, patients must move into a supervision room located next to or close to the medical clinic. This is to help prevent diversion of methadone to others. Patients in the supervision room must be monitored for around 15-20 minutes after dosing.

Effects of methadone

Methadone is a synthetic opioid agonist. This means it produces effects in the body in the same way as heroin, morphine and other opioids. It is taken orally as a tablet or syrup.

When an opioid dependent person takes methadone, it relieves withdrawal symptoms and opioid cravings; at a maintenance dose, it does not induce euphoria.

Onset of effects occurs 30 minutes after swallowing and peak effects are felt approximately three hours after swallowing. At first, the half-life (the length of time for which effects are felt) of methadone is approximately 15 hours; however, with repeated dosing, the half-life extends to approximately 24 hours. It can take between 3 and 10 days for the amount of methadone in the patient's system to stabilise.

Most people beginning MMT experience few side effects. However, there are some side effects of methadone, including:

• Disturbed sleep
• Nausea and vomiting
• Constipation
• Dry mouth
• Increased perspiration
• Sexual dysfunction
• Menstrual irregularities in women
• Weight gain

Interactions between methadone and other medications

Interactions between methadone and other drugs can lead to overdose or death. Drugs that depress the respiratory system (e.g. benzodiazepines) increase the effects of methadone. Drugs that affect metabolism can induce methadone withdrawal symptoms. Clinically important drug interactions are listed in Table 12 (p.83). In particular it is important to note interactions between methadone and medications used to treatment HIV and tuberculosis:

Table 12

Methadone-medication interactions.

• The HIV medications nevirapine and efavirenz increase metabolism of methadone, causing opioid withdrawal. Some protease inhibitors (PIs) may have the same effect, especially when associated to a small boosting dose of ritonavir.
• The tuberculosis medication rifampicin increases metabolism of methadone and reduces the half-life of methadone.

Patients receiving these medications, or other medications listed in Table 12, in combination with methadone should be monitored for signs of withdrawal or intoxication, and their methadone dose adjusted accordingly. See also AIDSinfo, http://www.hivatis.org/, for up-to-date listings of antiretroviral medications and interactions with other drugs.

Patients in methadone maintenance treatment can become tolerant to the pain-relieving effects of opioids. In the event that an MMT patient requires pain relief, non-opioid analgesics such as paracetamol can be given. If methadone patients are provided with opioid analgesics, they may require higher than normal doses to experience pain relief.

See also AIDSinfo, http://www.hivatis.org/, for up-to-date listings of antiretroviral medications and interactions with other drugs.