Seminar 4-6 GMed PDF

Substances of abuse/addiction Alcohol Nicotine Legal Most problematic in normal population Marijuana Amphetamines Heroin Cocaine Many of these are illegal or obtained illegally Steroids Ecstasy Benzodiazepines Alcohol In...

Substances of abuse/addiction Alcohol Nicotine Legal Most problematic in normal population Marijuana Amphetamines Heroin Cocaine Many of these are illegal or obtained illegally Steroids Ecstasy Benzodiazepines Alcohol In everyday use, alcohol usually refers to drinks such as beer, wine, or spirits containing ethyl alcohol Alcohol acts on the CNS and can cause changes in mood, emotions, behaviour and consciousness Alcohol is rapidly absorbed from the small bowel via portal circulation (around 80%), and stomach (around 20%). Alcohol is water soluble, and little or no alcohol enters fatty tissue. Alcohol is rapidly distributed throughout the body water accumulating in tissues with high water content. Alcohol readily crosses blood-brain and placental barriers. It reaches the brain within five minutes of ingestion, with blood concentrations peaking between 30 to 90 (typically 45) minutes. Health and medical complications Body system Complication Gastrointestinal Cirrhosis of liver. Hepatitis. Gastritis. Pancreatitis. Gastrointestinal haemorrhage. Malnutrition. Weight loss. Malabsorption. Cardiovascular Cardiac arrhythmias. Cardiomyopathy. Hypertension. Neurological Blackouts. Convulsions. Peripheral neuropathy. Acute confusional states. Head injuries. Long-term brain damage. Depression. Respiratory Pneumonia. Aspiration of vomitus while intoxicated. Reproductive Males: Hypogonadism – loss of libido, impotence, loss of secondary sexual characteristics, enlarged breasts. Females: Hypogonadism – loss of libido, menstrual irregularities, loss of secondary sexual characteristics. Musculoskeletal Gout Other Increase in cancers – particularly mouth, oesophagus, liver and colon. Increased risk of alcohol-related trauma. Increased risk of self-harm and suicide. Burden of disease - Australia Image:https://www.abc.net.au/news/2014-07- 31/alcohol-related-deaths-australia-2010/5637156 Burden of disease - Australia Safe alcohol use The National Health and Medical Research Council (NHMRC) Australian guidelines to reduce health risks from drinking alcohol (2009), recommend: For healthy men and women, drinking no more than two standard drinks on any day reduces the lifetime risk of harm from alcohol-related disease or injury. For healthy men and women, drinking no more than four standard drinks on a single occasion reduces the risk of alcohol related injury arising from that occasion. Parents and carers should be advised that children under 15 years of age are at the greatest risk of harm from drinking and that for this age group, not drinking alcohol is especially important. For young people aged 15–17 years the safest option is to delay the initiation of drinking for as long as possible. For women who are pregnant or planning a pregnancy, not drinking is the safest option. For women who are breastfeeding, not drinking is the safest option. Standard drink A standard drink is a unit of measurement. In Australia, a standard drink is any drink containing 10 grams of alcohol, regardless of container size or alcohol type (e.g beer, wine, spirit). alcoholthinkagain.com.au/Alcohol-Your-Health/What-is-a-Standard-Drink Standard drinks - Beer Standard drinks- Wine Standard drinks - Spirits Metabolism of ethyl alcohol More than 90% of the ethyl alcohol that enters the body is completely oxidized to acetic acid in the liver by alcohol dehydrogenase (ADH). The remainder of the alcohol is not metabolized and is excreted either in the sweat, urine, or given off in one’s breath. This is the basis of the breathalyser test and is the reason one can smell alcohol on the breath of someone who has been drinking recently. Blood alcohol concentration Blood alcohol concentration (BAC) refers to the amount of alcohol present in the bloodstream. A BAC of 0.05% (point 0 five) means that there is 0.05 grams of alcohol in every 100 millilitres of blood.  Blood alcohol concentration Ethyl alcohol distributes in the body in proportion to the water content in the particular tissue. Ethyl alcohol crosses with water into the blood stream, therefore the process of distribution of alcohol is rapidly speeded up. The more one drinks, the more alcohol would be in the blood. Blood alcohol concentration Brick, J., & Erickson, C. K. (2012). Drugs, the brain, and behavior : The pharmacology of abuse and dependence. Retrieved from http://ebookcentral.proquest.com Blood alcohol concentrations Alcohol and the adult brain Source http://www.kickoff.net.au/Alcohol.html Alcohol and the CNS Image: http://comprar-en-internet.net/worksheets/brain-parts-and-functions-worksheet.html Alcohol and neurotransmitters Four of the most important neurotransmitters with respect to alcohol are Glutamate – Ethyl Alcohol inhibits NMDA glutamate receptors, thus diminishing the excitatory actions of glutamate. Gamma aminobutyric acid (GABA) – ethyl alcohol facilitates the action of GABA the major inhibitory neurotransmitter in the brain. Dopamine – interacts with the reward system. Serotonin – plays a role in reward pathway and mood. Alcohol addiction – the reward system Image: Page 1210. Craft et al., (2019) The reward system is comprised ventral tegmental area, extended amygdala and the nucleus accumbens within that appear to be important in the reinforcing (rewarding) properties of a variety of drugs including alcohol. Addiction 1. Drug stimulates an increase in dopamine signalling from the ventral tegmental area (VTA) to the nucleus accumbens. 2. The nucleus accumbens “perceives” this dopamine signal and measures the “goodness” of the agent or the natural reward based on the size of the dopamine release. 3. Glutamate projections from the nucleus accumbens instruct the prefrontal cortex to remember the environment and behaviours which lead up to the occurrence of the “goodness”. 4. In addiction, excess signalling of glutamate neurons in the prefrontal cortex stimulates the nucleus accumbens, triggering drug-seeking behaviours at the expense of naturally rewarding or good behaviours. Image: Page 1210. Craft et al., (2019) Alcohol addiction A modified reward process where by drinking alcohol provides an overall positive effect (euphoria or decrease in an unpleasant situation). This is coupled with those vulnerable individuals with a pattern of diminishing or ignoring the negative impacts of overconsumption - the hangovers, loss of memory, fights, violence and arrests. The less vulnerable individual equates heavy alcohol consumption as overall unpleasant as a result of the negative effects outweighing the positive. Alcohol addiction Alcohol addiction takes place primarily through two means. Positive reinforcement Represents an environmental situation in which a rewarding stimulus or experience increases the chances that the individual displays a certain response. Negative reinforcement Refers to an increase in behavioural patterns, such as alcohol ingestion, if the behaviour facilitates the individual to circumvent or avoid an aversive stimulus (symptoms of withdrawal). Banerjee, N. (2014). Neurotransmitters in alcoholism: A review of neurobiological and genetic studies. Indian journal of human genetics, 20(1), 20. doi: 10.4103/0971-6866.132750 Alcohol & Mental Health People with mental health problems are at increased risk of experiencing problems relating to alcohol (people with both anxiety and depressive disorders have four times the rate of alcohol dependence). People diagnosed as having an alcohol dependence problem are also more likely to suffer from other mental health problems. - There is a high correlation between alcohol dependence and Posttraumatic Stress Disorder (PTSD). Alcohol use at well above low-risk levels is itself a causal factor in a number of mental health conditions. Alcohol and Mental Health. Australian Government. https://www.therightmix.gov.au/assets/factsheets/DVA0007_6_Alcohol_Mental_H ealth_v4.pdf Alcohol & Mental Health Drinking above the levels set in the Guidelines can lead to poorer outcomes for people who have mental health problems. In particular, people who are depressed and sometimes drink excessively are at much greater risk of self-harm and suicide, especially if they also drink regularly above guideline levels. Depression can be made worse by drinking excessively and can also be a consequence of dependent drinking patterns. While alcohol may bring some relief from anxiety or stress in the short term, it can worsen anxiety in the longer term, especially with binge drinking. Alcohol use above low-risk levels is associated with poorer outcomes for people suffering from schizophrenia. Alcohol can cause disrupted sleep, and interfere with the effect of medications. Alcohol can interact in harmful ways with most of the medications prescribed for mental health problems, even at low-risk levels of drinking (1–2 standard drinks). (Alcohol and Mental Health. Australian Government. https://www.therightmix.gov.au/assets/factsheets/DVA0007_6_Alcohol_Mental_Health_v4.pdf Neuroadaptation Neural adaptations to alcohol underlie the production of alcohol tolerance and the associated symptoms of withdrawal. Following cessation of alcohol the brain attempts to compensate for ethanol which influences normal functioning by altering the number or function of the receptors. The brain attempts to counteract the depressant effect of ethyl alcohol by increasing the activity of the glutamate system and decreasing the activity of the GABA system. Through neuroadaptation the brain is able in many instances to up-regulate (increase) or down-regulate (decrease) its function to compensate for the presence or absence of ethanol. Alcohol withdrawal syndrome Most people experience alcohol withdrawal syndrome 4-6 hrs after ingestion Typically known as “hangover” Nausea and vomiting Gastritis Headache Fatigue Sweating and thirst Cause of symptoms is unclear but is attributed to Restlessness dehydration, Irritability hypoglycaemia, and the ‘shakes’ accumulation of lactic acid Vasomotor instability and acetaldehyde in the blood If a person drinks at levels that put them at short-term harm… Source from: https://admin.americanaddictioncenters.org/wp-content/uploads/2015/10/alcohol-withdrawal.png Alcohol withdrawal Source: What is the Timeline for Alcohol Withdrawal. Origins Behavioural HealthCare. https://www.originsrecovery.com/timeline-alcohol-withdrawal/ Alcohol withdrawal Source: What is the Timeline for Alcohol Withdrawal. Origins Behavioural HealthCare. https://www.originsrecovery.com/timeline-alcohol-withdrawal/ Alcohol withdrawal Source: What is the Timeline for Alcohol Withdrawal. Origins Behavioural HealthCare. https://www.originsrecovery.com/timeline-alcohol-withdrawal/ Alcohol withdrawal This is only a rough timeline and it is important to note that withdrawal symptoms may vary from person to person. Use a rating scale to determine overall severity rather than rely on stages as a framework for understanding withdrawal. Withdrawal can commence between 6-24 hours after the last drink and can occur before the blood alcohol level is