The absorption of a drug is in part dependent upon its route of administration. Since psychoactive drugs must enter the bloodstream to reach their site of action, the route of administration is very important in the speed of influencing the physical and psychological effects of the drug. The routes of taking drug are oral, smoking, inhalation and by injection. The most common route of administration is oral, in either liquid or
tablet form. When a drug is required to act more rapidly the preferred route of administration is by injection. Drugs of misuse, such as heroin, are often administered intravenously, for example directly into a vein. Certain drugs are smoked, for example cannabis, crack cocaine, heroin. Some psychoactive drugs, for example cocaine and amphetamine, are also taken by the intranasal route. Identical drugs can produce different results depending on the route of administration. For example, naloxone, an antagonist of opiates, is given intravenously and is therefore used in the treatment of opiate overdose: the same drug, given orally, acts differently and is used in the treatment of constipation.
Oral
The oral route (swallowing) is the most popular method of drug administration although effectively the slowest route because of the slow absorption of the drug into the blood stream. There is no stigma attached, compared to smoking and injecting, to take a psychoactive substance orally either in tablet form or in the form of beverages containing alcohol or caffeine
Smoking
Smoking is also a very effective route where the drug is inhaled as in the case of tobacco or heroin smoking (‘chasing the dragon’). Cannabis or marijuana is also smoked in the form of a ‘joint’ which is usually mixed with tobacco.
Inhalation
The inhalation route (sniffing) is also used to self-administer drugs. Absorption of the drug is through the mucous membrane of the nose and mouth. The types of drugs that are inhaled include cocaine, tobacco snuff and volatile substances and solvents. Inhalation may also produce rapid absorption and response as in the case of crack cocaine.
Injecting
The methods of drug injecting include intramuscularly or subcutaneously and/or intravenously. Injection of drugs is less widespread than other routes of drug administration but also the most hazardous. The major dangers of injecting are risk of overdose because of the concentrated effect of this method. There is also the risk of infection from non-sterile injection methods including hepatitis B and HIV infections, abscesses, gangrene and thromboses. The onset of the effects of the drug is rapid when it is administered intravenously: this is a major reason why drugs are often self- administered by injecting. Drugs that are mainly injected include heroin, cocaine, amphetamines and some hypnosedatives. Table 5.2 summarises the complications of injecting.
KEY POINTS
• All the three interrelated factors, pharmacological properties, individual differences and context of use influence the individual experiences of drug taking. • Continued substance use among alcohol and drug users is driven more by
physiological and psychological dependence than by rational decisions.
• The patterns of drug or alcohol use and misuse for some individuals sometimes vary over a period of time.
• Experimental use of illicit psychoactive substance is usually a short-lived experience and the majority of people may confine their consumption to drugs that are socially acceptable.
• The most common drugs used by recreational users are alcohol, caffeine, nicotine, cannabis, LSD and ecstasy.
• A dependent user has progressed to regular and problematic use of a psychoactive drug or becoming a multiple drug user.
• Binge drinking is drinking with the intention of getting drunk.
• Chaotic use is referred to when an individual is regarded as taking a drug or drugs in a spontaneous way that tends not to follow any typical drug-using pattern. • The routes of administration are oral, smoking, inhalation and injection. • Injecting drugs is less widespread than other routes of drug administration but also
the most hazardous.
REFERENCES
Alcohol Concern (2007) Binge Drinking Factsheet Summary. London: Alcohol Concern. Drugscope (1997) Media Guide Glossary. London: Drugscope. http://www.drugscope.org.uk/
resources/mediaguide/glossary.
Ghodse, A.H. (1995) Drugs and Addictive Behaviour. Oxford: Blackwell Science.
Institute of Alcohol Studies (2004) Binge Drinking: Nature, Prevalence and Causes. St Ives: Institute of Alcohol Studies.
Institute for the Study of Drug Dependence (1996) Drug Abuse Briefings, 6th edition. London: ISDD.
54 OVERVIEW
Table 5.2 Complications of injecting
Equipment Agent Site of injection Effects
Environment Drug Trauma and Infection Overdose
Cooker Drug interactions Skin abscess Poisoning
Water Allergy Fat necrosis Infection
Filter Contaminants ‘Simple’ miss Thrombosis
Syringe Infectious agents Connective tissue Embolism
Needle Arterial injection
Nerves
Lungs, breasts, penises, necks
Adapted from Pates, R., McBride, A. and Arnold, K. (2005) Injecting Illicit Drugs, p. xiii. Oxford: Blackwell Publishing.
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MCM Research Limited (2004) WTAG Binge-drinking Research. Oxford: MCM Research Limited.
Nader, P.W. and Czoty, M.A (2005) PET imaging of dopamine D2 receptors in monkey models of cocaine abuse: genetic predisposition versus environmental modulation. American Journal of Psychiatry, 162: 1473–82.
Palfai, T. and Jankiewicz H. (1997) Drugs and Human Behaviour, 2nd edition. Madison: Brown & Benchmark.
Parker, H., Aldridge, J. and Measham F. (1998) Illegal Leisure: The Normalization of Adolescent Recreational Drug Use. London: Routledge.
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