CITAT (Lemonne @ 13-06-2008, 06:10)
En sån här undersökning betyder ju ingenting om man inte vet hur undersökningen gått till, eller hur? Om nu graden av farlighet överhuvudtaget ens tillför någon som helst relevans till diskussionen.
Det har varit uppe i en del media och publicerats i 'The Lancet'.
Det gick också en dokumentär på SVT för inte så länge sedan om forskningen och resultaten.
Personligen tycker jag att det är väldigt intressant ur den drogpolitiska synvinkeln, dit diskussionen har hamnat, att utgå ifrån vetenskapligt framtaget material istället för propaganda.
Utdraget är ur 'The Lancet':
"Categories of harm
There are three main factors that together determine the harm associated with any drug of potential abuse: the physical harm to the individual user caused by the drug; the tendency of the drug to induce dependence; and the effect of drug use on families, communities, and society.5, 6, 7 and 8
Physical
Assessment of the propensity of a drug to cause physical harm—ie, damage to organs or systems—involves a systematic consideration of the safety margin of the drug in terms of its acute toxicity, as well as its likelihood to produce health problems in the long term. The effect of a drug on physiological functions—eg, respiratory and cardiac—is a major determinant of physical harm. The route of administration is also relevant to the assessment of harm. Drugs that can be taken intravenously—eg, heroin—carry a high risk of causing sudden death from respiratory depression, and therefore score highly on any metric of acute harm. Tobacco and alcohol have a high propensity to cause illness and death as a result of chronic use. Recently published evidence shows that long-term cigarette smoking reduces life expectancy, on average, by 10 years.9 Tobacco and alcohol together account for about 90% of all drug-related deaths in the UK.
The UK Medicines and Healthcare Regulatory Authority, in common with similar bodies in Europe, the USA, and elsewhere, has well-established methods to assess the safety of medicinal drugs, which can be used as the basis of this element of risk appraisal. Indeed several drugs of abuse have licensed indications in medicine and will therefore have had such appraisals, albeit, in most cases, many years ago.
Three separate facets of physical harm can be identified. First, acute physical harm—ie, the immediate effects (eg, respiratory depression with opioids, acute cardiac crises with cocaine, and fatal poisonings). The acute toxicity of drugs is often measured by assessing the ratio of lethal dose to usual or therapeutic dose. Such data are available for many of the drugs we assess here.5, 6 and 7 Second, chronic physical harm—ie, the health consequences of repeated use (eg, psychosis with stimulants, possible lung disease with cannabis). Finally, there are specific problems associated with intravenous drug use.
The route of administration is relevant not only to acute toxicity but also to so-called secondary harms. For instance, administration of drugs by the intravenous route can lead to the spread of blood-borne viruses such as hepatitis viruses and HIV, which have huge health implications for the individual and society. The potential for intravenous use is currently taken into account in the Misuse of Drugs Act classification and was treated as a separate parameter in our exercise.
Dependence
This dimension of harm involves interdependent elements—the pleasurable effects of the drug and its propensity to produce dependent behaviour. Highly pleasurable drugs such as opioids and cocaine are commonly abused, and the street value of drugs is generally determined by their pleasurable potential. Drug-induced pleasure has two components—the initial, rapid effect (colloquially known as the rush) and the euphoria that follows this, often extending over several hours (the high). The faster the drug enters the brain the stronger the rush, which is why there is a drive to formulate street drugs in ways that allow them to be injected intravenously or smoked: in both cases, effects on the brain can occur within 30 seconds. Heroin, crack cocaine, tobacco (nicotine), and cannabis (tetrahydrocannabinol) are all taken by one or other of these rapid routes. Absorption through the nasal mucosa, as with powdered cocaine, is also surprisingly rapid. Taking the same drugs by mouth, so that they are only slowly absorbed into the body, generally has a less powerful pleasurable effect, although it can be longer lasting.
An essential feature of drugs of abuse is that they encourage repeated use. This tendency is driven by various factors and mechanisms. The special nature of drug experiences certainly has a role. Indeed, in the case of hallucinogens (eg, lysergic acid diethylamide [LSD], mescaline, etc) it might be the only factor that drives regular use, and such drugs are mostly used infrequently. At the other extreme are drugs such as crack cocaine and nicotine, which, for most users, induce powerful dependence. Physical dependence or addiction involves increasing tolerance (ie, progressively higher doses being needed for the same effect), intense craving, and withdrawal reactions—eg, tremors, diarrhoea, sweating, and sleeplessness—when drug use is stopped. These effects indicate that adaptive changes occur as a result of drug use. Addictive drugs are generally used repeatedly and frequently, partly because of the power of the craving and partly to avoid withdrawal.
Psychological dependence is also characterised by repeated use of a drug, but without tolerance or physical symptoms directly related to drug withdrawal. Some drugs can lead to habitual use that seems to rest more on craving than physical withdrawal symptoms. For instance, cannabis use can lead to measurable withdrawal symptoms, but only several days after stopping long-standing use. Some drugs—eg, the benzodiazepines—can induce psychological dependence without tolerance, and physical withdrawal symptoms occur through fear of stopping. This form of dependence is less well studied and understood than is addiction but it is a genuine experience, in the sense that withdrawal symptoms can be induced simply by persuading a drug user that the drug dose is being progressively reduced although it is, in fact, being maintained at a constant level.10
The features of drugs that lead to dependence and withdrawal reactions have been reasonably well characterised. The half-life of the drug has an effect—those drugs that are cleared rapidly from the body tend to provoke more extreme reactions. The pharmacodynamic efficacy of the drug also has a role; the more efficacious it is, the greater the dependence. Finally, the degree of tolerance that develops on repeated use is also a factor: the greater the tolerance, the greater the dependence and withdrawal.
For many drugs there is a good correlation between events that occur in human beings and those observed in studies on animals. Also, drugs that share molecular specificity (ie, that bind with or interact with the same target molecules in the brain) tend to have similar pharmacological effects. Hence, some sensible predictions can be made about new compounds before they are used by human beings. Experimental studies of the dependence potential of old and new drugs are possible only in individuals who are already using drugs, so more population-based estimates of addictiveness (ie, capture rates) have been developed for the more commonly used drugs.11 These estimates suggest that smoked tobacco is the most addictive commonly used drug, with heroin and alcohol somewhat less so; psychedelics have a low addictive propensity.
Social
Drugs harm society in several ways—eg, through the various effects of intoxication, through damaging family and social life, and through the costs to systems of health care, social care, and police. Drugs that lead to intense intoxication are associated with huge costs in terms of accidental damage to the user, to others, and to property. Alcohol intoxication, for instance, often leads to violent behaviour and is a common cause of car and other accidents. Many drugs cause major damage to the family, either because of the effect of intoxication or because they distort the motivations of users, taking them away from their families and into drug-related activities, including crime.
Societal damage also occurs through the immense health-care costs of some drugs. Tobacco is estimated to cause up to 40% of all hospital illness and 60% of drug-related fatalities. Alcohol is involved in over half of all visits to accident and emergency departments and orthopaedic admissions.12 However, these drugs also generate tax revenue that can offset their health costs to some extent. Intravenous drug delivery brings particular problems in terms of blood-borne virus infections, especially HIV and hepatitis, leading to the infection of sexual partners as well as needle sharers. For drugs that have only recently become popular—eg, 3,4-methylenedioxy-N-methylamphetamine, better known as ecstasy or MDMA—the longer-term health and social consequences can be estimated only from animal toxicology at present. Of course, the overall use of a drug has a substantial bearing on the extent of social harm.
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Din inställning till droger?, Hur ser din mörka historia ut?
12-06-2008, 18:31
