Biochemical and pharmacological rationale for addiction

Behaviour | May 23, 2014 | Author: The Super Pharmacist

quit, addiction, relapse, marajuana, alcohol

Biochemical and pharmacological rationale for addiction
  • About 7% of Australians have consumed amphetamine at some point of their life
  • About 3% of Australians use prescription analgesics for non-medical reasons
  • Data from Australian Institute of Health and Welfare suggested that about 20.1% people consume alcohol in doses that may endanger their life.
  • Latest statistics suggest that there has been a substantial increase in the population of individuals who consume prescription and non-prescription drugs.
  • Research and clinical data indicates that addiction to one substance increases the chances of developing addiction to multiple addictive substances (1).

It has been observed that vast majorities of people who consume drugs have no idea that they may develop dependence or addiction with unsupervised use. According to statistics reported by Australian Drug Foundation (1), individuals using serious drugs of addiction usually started using legal drugs like alcohol, the most frequently used and abused legal drug in Australia. Most people initiate drug use for recreational purposes or as a result of social pressures.

What are notable symptoms of Drug Addiction?

  • Recreational use of drugs can be differentiated from drug dependence or addiction by these symptoms:
  • Intense craving for the drug that the user consume
  • Inability to quit the drug use despite conscious or intentional efforts
  • Spending a fair sum of money on drugs or engaging in criminal or illegal activities to support drug habits, such as stealing or violence
  • Spending most of the time in getting and consuming the drugs
  • Intoxication or drug use that interfere with the normal daily activities. These can effect family, relationships, work, school etc.

What causes addiction?

There is no one identifiable reason as to why some people develop addiction or dependence on drugs while others do not. Psychologists and psychotherapists believe that addiction usually have multi-factorial origin – such as a complex and complicated interplay of biochemical, psychological, social and physiological factors.

Pharmacological characteristics of drugs and role of biochemical changes:

Addiction can be differentiated from habituation on the grounds of physical dependence. Most drug users develop psychological dependence in the beginning that is marked by a persistent craving for the drug. However, with continued use, drug users can develop physical dependence as well that is characterised by development of undesired physical symptoms with the withdrawal of active substance. This may range from mild changes such as:

  • irritability
  • agitation
  • anxiety
  • sweating

To strong symptoms such as:

  • changes in blood pressure
  • changes in heart rate
  • changes in breathing rate
  • nausea
  • vomiting
  • diarrhoea or constipation
  • lethargy
  • altered level of consciousness
  • death.

Some drugs have a higher addiction potential such as the illicit substances cocaine and heroin. Individuals who consume these drugs develop addiction earlier than lower addiction potential drugs such as marijuana and alcohol. Research conducted by German scientists Herz (4) and associates suggested that most illicit and some prescription drugs, such as opioid pain killers, activate particular areas of the brain that are associated with reward and pleasure. Intake of these drugs activate receptors and release certain neurotransmitters like dopamine that are released in times of pleasure and reward. According to another study published in European Journal of Pharmacology (5) investigators suggested that all addictive drugs share one common feature; activation of transmission of dopamine in reward centers of brain that reinforce the drug consuming behavior. The incidence of multi-drug addiction increases in drugs that share similar metabolism and functioning within the body. Research published in Trends in Pharmacological Sciences (6) suggested that cannabinoid users are at higher risk of developing addiction to opiates because these two drugs share biochemical and pharmacological activity within the body. This knowledge is helpful in clinical practice where healthcare professionals should avoid prescribing opiates in individuals with a confirmed history of cannabinoid use. Other factors that also play a very important role in drug addiction are:

Genetical Factors:

It has been observed that positive family history of addiction or certain psychological issues increases the risk of developing dependence on drugs. It also depends on how accessible the drugs are to users. It has been demonstrated that when family members and other same home occupants use drugs, other members of the household are more susceptible to develop addiction. A report published in the peer reviewed Nature Neuroscience (7) suggested that certain personality traits are highly associated with an increased risk of drug use, drug dependence and addiction. The report defined impulsive behavior, vulnerability to stressful events, risk-taking behavior as positive marker to development of addiction.

Environmental factors:

Peer pressure, stressful working environment, long working hours, weak family ties, unhealthy domestic atmosphere, exposure to drugs and easy-availability of illicit or prescription drugs have all been identified as contributing factors to the development of drug addiction.

Psychological factors:

People with poor social skills, individuals with known history of depression, anxiety disorders and other mental health issues can contribute to addiction. Investigator J Chao and associates (8) defined addiction as a form of neural plasticity and compulsive disorders that are induced by drug use. According to Chao, chronic drug use introduce changes in the genetic expression of certain chemicals such as up-regulation of cyclic AMP – a second messenger pathway that is responsible for tolerance. Tolerance to a drug indicates the requirement of higher doses of drug to achieve the same result.

Gender:

Drug addiction is more common in males as compared to females. According to latest data, approximately 43.2% males engage in at least one episode of illicit drug use; as opposed to 36.5% females.

History of addiction:

Certain other factors that also increases the risk of addiction are:

  • History of smoking
  • History of alcohol consumption

Common drugs of abuse

Hashish and Marijuanamarijuana

Users of marijuana may have the urge to use it every day. The biochemical rationale of marijuana use is based on its many active constituents such as THC (tetrahydrocannabinol) that leads to psychological dependence. Signs and symptoms of Marijuana abuse are:

  • Alteration in the short term memory
  • Bloodshot eyes
  • Slow reflexes
  • Poor or no coordination
  • Changes in the heart rate and blood pressure
  • Inability to concentrate
  • Heightened perception of auditory, visual and olfactory stimulations.
  • Increase in appetite
  • Paranoid thinking

Current prevalence of marijuana use in Australia is approximately 10.1% (3) of the total population. Treatment strategies mainly revolves around psychological counseling, patient education and in patient admission to stop the marijuana use.

Inhalants

The biochemical element of addiction in case of inhalants is dependent on the substance being inhaled by the user. Most frequently used inhalants are; paint thinners, household aerosol materials, fluid of felt tip markers, cleaning liquids, gasoline and glue. Such substances, when used, usually cause minimal intoxication and decrease inhibition. Long-term use of such drugs can have severe effects such as

  • Seizures
  • Damage to cardiovascular organs and apparatus
  • Kidney and liver damage
  • Neurological damage
  • Deaths in extreme cases

More than 1.5% Australians are physically and psychologically dependent on inhalants. Treatment strategies require detoxification following discontinuation of the substance, since most inhalants deposit amounts of the drug in fatty tissues. This means individuals may experience withdrawal symptoms for extended periods. Supportive care, peer group interaction and absolute abstinence are most effective treatment options for inhalants.

Club drugs

EcstasyAs the name suggests, these drugs are mostly commonly used by teenagers and young adults at parties, clubs and concerts. These drugs include ketamine, amphetamine, ecstasy, GHB and flunitrazepam (Rohypnol, Hypnodorm). Although these drugs are not similar in effect or chemical class, they have many similar potential outcomes. These include:

  • Reduction in inhibition
  • Changes in normal memory processes
  • Changes in heart rate
  • Heightened feelings of excitement and happiness
  • Distorted judgment
  • Unconsciousness or drowsiness (flunitrazepam and GHB)
  • Sense of taste, sight or sound becomes heightened

Treatment options vary for different drugs. Cognitive Behavioral Therapy (CBT), family therapy and recreation therapy can be useful. Other therapeutic options include hypnotherapy, biofeedback/neurofeedback and dialectical behavioral therapy.

Narcotic painkillers

This category includes methadone, morphine, oxycodone and codeine. The addiction to prescription drugs is usually reported in individuals with a chronic health issue, such as fibromyalgia, rheumatoid arthritis, osteoarthritis and post-surgical pain management. About 4.2 to 7% of Australian adult population is addicted to pharmaceutical or prescription pain-killers (3). Common symptoms that indicate addiction to prescription pain killers include:

  • Depressed patients
  • History of constipation
  • Needle marks in the case of injectable pain-killers
  • A psychological need to continue pain-killers even if the primary condition has been resolved
  • Tolerance, requiring a need to increase dosage to obtain the same pain relief

Treatment options are mostly pharmacological in addition to psychological and supportive due to high risk of physical dependence and severity of withdrawal symptoms. Some notable options include methadone and combination buprenorphine with naloxone.

Legal Drugs:

Certain nervous stimulants (nicotine) or depressants (alcohol) which are legal in Australia further increases the risk of addiction of illicit drugs by acting as a ‘gateway drug’ and activating addiction pathways. According to latest data:

  • Men in Australia are almost twice as likely to consume alcohol than women on regular basis (1)
  • Regardless of the amount or frequency of intake; alcoholic males are 30% more likely to suffer alcohol related injury
  • Approximately 580,000 hospital admissions in Australia are attributed to direct or indirect effects of alcohol each year
  • In Australia, younger females (aged 12 to 17 years) are more likely to adopt smoking than males in that age group (3.2% vs. 1.8%); however, in adult males and females, the ratio of male smokers is much higher than that of female smokers.
  • Over 87.9% of all Australians over the age of 15 years reported consuming alcohol on at least one occasion during their lifetime.
  • More than 51.6% Australians consume alcohol in more than recommended doses

For alcohol dependence, the best treatment modality is abstinence and detoxification (in chronic abusers). For nicotine addiction, nicotine replacement therapy or prescription medications used in conjunction with counseling have been shown to be the most successful methods for quitting.

Why is it important to control drug addiction?

Health issues – Unsupervised and long term consumption of drugs can increase the risk of several health issues. Lack of an ability to make sensible decisions – Drugs (both illicit and prescription) induces a state of euphoria that affects the capacity to think, understand and interpret situations. There is always a risk of drug overdose that may lead to permanent disability and other complications. Compromised quality of life and relationships – Individuals who consume drugs often have issues in maintaining normal social, personal and family relationships. Financial problems: Intoxication affects the ability of a person to engage in productive activities combined with the expenses associated with drug use. Diseases: Under the influence, more people are likely to engage in inappropriate or risky behaviors such as unprotected intercourse, use of shared needles, assaults and other issues. This directly increases the risk of developing mental, physical and psychological issues such as infectious diseases (HIV, Hepatitis B and C) and sexually transmitted diseases (chlamydia, gonorrhea, syphilis). Legal Issues: Consumption of illicit drugs is a criminal offence itself in most cases. Users, as a result of financial and decision making issues, adopt criminal means to obtain drugs. Additionally, most drug addicts engage in violent crimes under the influence.

How to manage Drug Addiction?

Management of drug addiction may be problematic due to biochemical and psycho-physical factors. Challenges exist for the addict, family members and physicians to successfully treat drug addiction. It is also very important to adopt strategies and interventions to prevent relapse. It is highly recommended to see a registered and experienced therapy physician. The primary aim of therapy to treat addiction includes identifying risk factors for drug use and pathophysiological basis of addiction in order to effectively address the issue. According to data reported by Australia Drug Foundation (1), about 95,852 males and 47,733 females enrolled in drug and alcohol treatment program in the past year.

Coping and Preventing Relapse:

Join support groups: ceasing the use of drugs of addiction although challenging, pails in comparison to the long-term struggle that resists relapse. Joining support groups and connecting with others in similar situations, learning how they cope with their urges and desires can help in preventing relapse. Seek help for related health issues: If you have a known psychological stressor or health issue; seek help to manage your problems

References:

  1. http://www.druginfo.adf.org.au/attachments/1091_menandsubstanceuseposter.jpg
  2. Australian Institute of Health and Welfare. (2011). 2010 National drug strategy household survey report. Drug Statistics Series.
  3. http://www.aihw.gov.au/publication-detail/?id=32212254712&tab=2
  4. Herz, A., Shippenberg, T. S., Bals-Kubik, R., & Spanagel, R. (1992). [Opiate addiction. Pharmacologic and biochemical aspects]. Arzneimittel-Forschung, 42(2A), 256-259.
  5. Di Chiara, G. (1999). Drug addiction as dopamine-dependent associative learning disorder. European journal of pharmacology, 375(1), 13-30.
  6. Manzanares, J., Corchero, J., Romero, J., Fernández-Ruiz, J. J., Ramos, J. A., & Fuentes, J. A. (1999). Pharmacological and biochemical interactions between opioids and cannabinoids. Trends in Pharmacological Sciences, 20(7), 287-294.
  7. Kreek, M. J., Nielsen, D. A., Butelman, E. R., & LaForge, K. S. (2005). Genetic influences on impulsivity, risk taking, stress responsivity and vulnerability to drug abuse and addiction. Nature neuroscience, 8(11), 1450-1457.
  8. Chao, J., & Nestler, E. J. (2004). Molecular neurobiology of drug addiction. Annu. Rev. Med., 55, 113-132
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