Section V

The INCB and the WHO have called attention to the inadequate treatment of pain and have concluded that this is due, in part, to overly restrictive laws and regulations that impede the adequate availability and medical use of opioids (3, 4, 5, 9, 10, 11). ^[5]

As early as 1986, the participants of the WHO Meeting on the Comprehensive Management of Cancer Pain (6) recognized the need to update national drug regulatory systems to respond to changing medical needs:

In 1986, the participants of the WHO Meeting on the Comprehensive Management of Cancer Pain (6) further clarified the objectives of the Single Convention on Narcotic Drugs of 1961, as amended by the 1972 Protocol Amending the Single Convention on Narcotic Drugs, 1961 (hereafter referred to as “the 1961 Convention,” see Annex 1) and the 1971 Convention on Psychotropic Substances:

In 1989, the INCB (9) drew attention to some governments’ overreaction to the drug abuse problem when:

“...the reaction of some legislators and administrators to the fear of drug abuse developing or spreading has led to the enactment of laws and regulations that may, in some cases, unduly impede the availability of opiates. The problem may also arise as a result of the manner in which drug control laws and regulations are interpreted or implemented” (p. 1).

“...legislators sometimes enact laws which not only deal with the illicit traffic itself, but also impinge on some aspects of licit trade and use, without first having adequately assessed the impact of the new laws on such licit activity. Heightened concern with the possibility of abuse may also lead to the adoption of overly restrictive regulations which have the practical effect of reducing availability for licit purposes” (p. 15).

Indeed, the long-term use of opioids for pain has been discouraged traditionally because of the perceived risk of “drug dependence.” Separation of perceptions and myths from reality requires accurate use of terminology.

Terminological confusions can deter both doctors and patients from the use of opioids even when there is a strong medical justification for their use. Two inter-related but different confusions may occur: (i) confusion between “abuse” (or “misuse”) and long-term medical use, and (ii) confusion between “addiction” and “dependence.”

Concerning the first confusion, the principal aim of the 1961 Convention is to prevent the abuse of narcotic drugs while ensuring their availability for medical use. It is therefore very important to make a clear distinction between abuse and medical use of narcotic drugs.

The 1961 Convention does not define the terms “misuse” or “abuse.” However, “abuse” is defined by the WHO Expert Committee on Drug Dependence (19) as follows:

“persistent or sporadic excessive drug use inconsistent with or unrelated to acceptable medical practice” (p. 6).

From this definition, it is clear that medical use of drugs, whether long-term or not, and whether adverse drug reactions (including “drug dependence”) occur or not, is not “drug abuse.”

The confusion between “addiction” and “dependence” is more difficult to clarify because WHO no longer uses the term “addiction.” Hence there is no authoritative WHO definition of “addiction” to compare with that of “dependence.” ^[6]

The current definition of “dependence” ^[7] given by the WHO Expert Committee on Drug Dependence (8) is:

“A cluster of physiological, behavioural and cognitive phenomena of variable intensity, in which the use of a psychoactive drug (or drugs) takes on a high priority. The necessary descriptive characteristics are preoccupation with a desire to obtain and take the drug and persistent drug-seeking behaviour. Determinants and problematic consequences of drug dependence may be biological, psychological or social, and usually interact” (p. 5).

The core concept of the WHO definition of “drug dependence” requires the presence of a strong desire or a sense of compulsion to take the drug.

Clinical guidelines (ICD-10) for a definite diagnosis of “dependence” drawn up by WHO require that three or more of the following six characteristic features have been experienced or exhibited (21):

(b) difficulties in controlling substance-taking behaviour in terms of its onset, termination, or levels of use;

(c) a physiological withdrawal state when substance use has ceased or been reduced, as evidenced by: the characteristic withdrawal syndrome for the substance; or use of the same (or a closely related) substance with the intention of relieving or avoiding withdrawal symptoms;

(d) evidence of tolerance, such that increased doses of the psychoactive substance are required in order to achieve effects originally produced by lower doses;

(e) progressive neglect of alternative pleasures or interests because of psychoactive substance use, increased amount of time necessary to obtain or take the substance or to recover from its effects;

(f) persisting with substance use despite clear evidence of overtly harmful consequences, such as harm to the liver through excessive drinking, depressive mood states consequent to periods of heavy substance use, or drug-related impairment of cognitive functioning; efforts should be made to determine that the user was actually, or could be expected to be, aware of the nature and extent of the harm (p. 75-76).

It is clear that a cancer patient requiring increased doses of an opioid for pain relief (see Annex 1 for definition of “tolerance”), who also develops withdrawal symptoms (see Annex 1 for definition of “withdrawal syndrome”) upon discontinuation of the drug, meets only two of the three required conditions for a positive diagnosis of dependence syndrome. The patient is therefore not opioid dependent, unless he or she additionally meets at least one of the four remaining conditions listed above (a, b, e or f).

The WHO Expert Committee on Cancer Pain Relief and Active Supportive Care (5) points out that “dependence” occurs rarely in cancer patients:

“Studies have shown that, while withdrawal syndrome and tolerance do occur in patients who take opioids over a long period, [drug] dependence is extremely rare. Consequently, the risk of [drug] dependence should not be a factor in deciding whether to use opioids to treat the cancer patient with pain” (p. 58).

The adverse drug reaction reports from the WHO Collaborating Centre for International Drug Monitoring at Uppsala, Sweden, support this observation. In the framework of the WHO programme for international drug monitoring, “drug dependence” is defined as one of the adverse drug reactions to be monitored and reported to this Collaborating Centre by the participating national monitoring centres. As of 1999, 56 countries participate in this international programme and the database contains more than two million adverse drug reaction case reports. The list of drugs for which “drug dependence” has ever been reported to this system indicates that only modest numbers of drug dependence cases have been associated with the use of opioid analgesics and that “dependence” has been reported for many other drugs, controlled as well as uncontrolled (22).

^[5] For a discussion of all the impediments to cancer pain relief, palliative care and opioid availability, see: WHO, 1990 (4); 1996 (5).

^[6] In order to understand the difference between “addiction” and “drug dependence,” it is necessary to briefly review the history of the evolution of the concept of “drug dependence.” During the 1960s, the WHO Expert Committee on Addiction-Producing Drugs (20) made serious attempts to clarify the difference between “addiction” and “habituation,” only to abandon this effort and to propose instead the use of the term “drug dependence.” In the minds of some experts, this led to the misunderstanding that the meaning of the then new term “dependence” would be the same as “addiction” or “habituation,” or both of them combined. This was not the case. As emphasized by that Expert Committee, the term “dependence” carried no connotation of the degree of risk to public health. This was a major difference from the term “addiction,” which did carry such a connotation.

^[7] The same Expert Committee (8) also recommended against efforts to distinguish between “physical dependence” and “psychic dependence,” because it felt that all drug effects on the individual are potentially understandable in biological terms. In addition, the Committee noted that “physical dependence” had been confusing to some clinicians because the manifestation of withdrawal syndrome (see Annex 1 for definition) was interpreted as evidence of both “physical dependence” and “drug dependence.”


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