Best Practices : Substance Abuse Treatment and Rehabilitation

a) Pharmacotherapies

Included under this heading is any treatment involving the administration of drugs. Four classes of drugs are considered: antidipsotropic drugs that induce an unpleasant reaction when used with alcohol; anti-craving drugs that reduce the craving for alcohol; psychotropic drugs that are prescribed to improve the user's psychological status, on the assumption that this will result in reduced drinking; and pharmacotherapies for drugs other than alcohol. However, only antidipsotropic and psychotropic drugs were considered in the reviews by Holder et al. (1991) and Finney and Monahan (1996).

As can be seen from Table 1, Holder et al. identified 10 controlled studies of oral disulfiram, five studies of disulfiram implants, one study of oral calcium carbimide, 10 studies of metronidazole, four studies of antidepressants, six studies of lithium, two studies of anti-psychotic drugs and eight studies of psychedelics (LSD) and 4 studies of antidepressants.

Finney and Monahan (1996) do not use Holder et al.'s categories to classify these types of drug treatment as having "good," "fair," etc., evidence of effectiveness. However, the rankings given to specific drugs by Holder et al. and Finney and Monahan show some similarities and some differences (see Table 2).

These differences reflect differences in the studies selected for review, the comparisons made and methods of analysis. Landry (1995) points out that various studies may have produced dissimilar results because they involved patients with different characteristics and motivations.

Antidipsotropic Drug Therapy for Alcohol: Disulfiram implants are ranked 10th by Holder et al. and are considered to have "fair" evidence of effectiveness. However, Finney and Monahan rank these implants in fourth place and compute an effectiveness index that is similar in size to those computed for social skills training and marital behavioural therapy. The rankings for oral disulfiram are also quite different in the two schemes. Holder et al. rank oral disulfiram in seventh place and consider that there is "fair" evidence for its effectiveness. In contrast, Finney and Monahan put oral disulfiram in 20th place with a high negative effectiveness index.

Landry also suggests that disulfiram therapy can be an effective adjunct to a comprehensive treatment program that includes methods to: help patients adhere to the disulfiram regimen; increase motivation for compliance; and promote relapse prevention.

A recent review of studies of disulfiram (Hughes and Cook, 1997) examined 24 outcome studies of oral disulfiram and 14 studies of disulfiram implants. In general, these studies were considered to be methodologically weak and their interpretation was hampered by differences in methods and subjects. Often, subjects in studies of oral disulfiram were coerced into treatment. The reviewers conclude that these studies do not support disulfiram implants and provide mixed support for oral disulfiram. Oral disulfiram seemed to be most useful when used selectively with patients involved in comprehensive programs. Although limited, the evidence suggested socially stable clients are more likely to benefit from disulfiram than others. A similar conclusion was reached following a review of anti-alcohol medications by Correctional Service of Canada (1996). This review also noted that patients who were highly motivated and compliant also benefit more from anti-alcohol drugs than others.

Metronidazole, another antidipsotropic medication used in the 1960s and 1970s, was not judged to be effective by either Holder et al. or Finney and Monahan. Similarly, the evidence for the use of calcium carbimide was too limited to merit definite conclusions.

Anti-craving Drug Therapy for Alcohol: Drugs used for this purpose are fluoxetine, zimelidine and citalopram. Placebo controlled double-blind trials using these drugs with non-depressed, mildly/moderately dependent alcoholics have consistently decreased short-term alcohol intake by an average of 10% to 20% (Anton, 1994). Other drugs, for example 5-HT agonist buspirone and 5-HT antagonist ritansarin, may reduce craving, but results of controlled trials are inconsistent. More recent studies of controlled clinical trials have found no difference in outcomes in either depressed or non-depressed alcoholics, when compared with use of placebos (Naranjo and Bremner, 1994).

Another drug that has recently been used in studies involving social and heavy drinkers is naltrexone. This is an opiate antagonist that also seems to reduce craving for alcohol. In several studies, including those with alcohol-dependent subjects, those receiving naltrexone drank on fewer days and were less likely to relapse to heavy drinking than those given a placebo (Volpicelli et al., 1994). Naltrexone has recently been approved for use in alcohol treatment in both the United States and Canada, and is increasingly recognized as a valuable component of comprehensive treatment.

Psychotropic Drug Therapy for Alcohol: This class of drugs includes anti-anxiety drugs, lithium, anti-psychotic drugs, anti-depressants and psychedelics. Holder et al. (1991) concluded that there was fair evidence to support the use of antidepressants in the treatment of alcohol problems and the evidence for other drugs was either indeterminate (lithium), too limited to merit definite conclusions (antipsychotic medication) or clearly not supportive of their use (psychedelics, antianxiety drugs). Finney and Monahan (1996) also gave antidepressants a similar ranking to Holder et al., and the rankings they gave to other psychotropic drugs indicates insufficient support for their use.

Treatment for Other Drugs: A variety of drugs has been used to treat people dependent on drugs other than alcohol, but there have been few controlled trials. The NIDA Review (1996) describes research in progress to determine the effectiveness of various drugs to treat heroin addiction. One such drug is buprenorphine. This is a partial opiate agonist that appears to reduce craving for heroin. However, to reduce the abuse potential of this drug, naloxone, an opiate antagonist, is presently being combined with buprenorphine in tablet form. Buprenorphine has not been approved for use in Canada.

The NIDA Review also notes several drugs that are currently being researched to reduce craving for cocaine. Also, trials are under way to develop a cocaine-like compound to immunize against cocaine. The review also notes that there is some evidence that bupropion, an antidepressant, may reduce cocaine use in moderately depressed clients who use cocaine and crack.

Heroin, has been used as a "maintenance" drug in the United Kingdom and there is evidence of beneficial short-term effects, with some individuals having been successfully stabilized on prescribed heroin for many years (Mitcheson and Hartnoll, 1978; Stimson and Oppenheimer, 1982). However, the prescription of heroin for addiction is currently quite rare in the United Kingdom. An ongoing study in Switzerland has shown that the prescription of heroin for intravenous use, or a prescription for intravenous methadone, is associated with significant improvement in health and lifestyles of heavily dependent socially marginalized narcotic addicts. In some cases, these positive outcomes have been sustained over more than two years (Uchtenhagen et al., 1996).

Methadone, is a synthetic, long-acting opiate-like drug that has been used extensively either to support addicts being withdrawn from opiate use or as a treatment maintenance drug. Methadone substitutes for other opiates and thereby prevents the onset of withdrawal symptoms and blocks the euphoric effects of heroin. Methadone's oral use eliminates the hazards of injection drug use.

There have been many studies of methadone maintenance treatment (Hall, 1996) and it is clear that, in adequate doses and with supportive therapy, methadone reduces illicit opiate use and criminal activity, improves social health and productivity, improves physical health, reduces HIV transmission, and improves pregnancy outcomes for addicted women. Methadone is also safe for long-term use and outcomes are positively associated with retention in treatment (Landry, 1995).

A review of methadone treatment by the Institute of Medicine (1990) in the United States concluded that methadone dosages should be individually tailored. However, the review also noted that patients maintained on higher doses (80 mg) generally do better than those on lower doses.

Research has also shown that methadone maintenance treatment pays for itself in economic terms. Studies by the National Institute on Drug Abuse in the United States have estimated that in 1991, the costs to society of an untreated heroin user on the street was US$43,000 and the cost of keeping the individual in jail or in a drug-free program were US$34,000 and US$11,000, respectively. However, the cost of one year of methadone maintenance treatment was only US $2,400.

Other drugs that can be used in the treatment of heroin addiction are clonidine (for the treatment of withdrawal), naltrexone (blocks the effects of opiates), LAAM (l-alpha- acetylmethadol) and codeine . LAAM is like methadone, but its effects last longer and it can be taken only every 72 hours (methadone is usually taken every 24 hours). None of these drugs is used extensively and LAAM has not been approved for use in Canada.

Best Practice Guideline (No. 1)

There is a definite role for pharmacotherapies, if used in a controlled setting, as an adjunct to other forms of treatment. Those drugs which have addictive potential must be used with caution and monitored on a regular basis.

Selective use of disulfiram by socially stable, motivated clients, as an adjunct to comprehensive therapy, is supported by the literature.

Naltrexone can be an effective adjunct to other forms of treatment by reducing craving for alcohol.

Methadone, in adequate doses and with supportive therapy, is effective in reducing illicit opiate use, criminal activity and HIV transmission. Therapy involving methadone can improve social functioning, physical health and productivity and, in certain instances, can lead to cessation of heroin use. Better outcomes are achieved with longer retention in treatment.