Transcript الشريحة 1
ابتسام الشدي EBTESAM AL-SHEDDI Email: [email protected] Site: faculty.ksu.edu.sa/10252 THE COURSE TOPICS DEPRESSANTS CANNABIS HALLUCINOGEN BY THE END OF THIS COURSE You should be able to: Identify the different classes of depressant drugs and to determine their effects on the human on short and long run and the possible signs and symptoms of withdrawal Determine the different classes of hallucinogenic substance and their effects Know the cannabis class and its effect THE ASSESSMENT TASKS DURING THE SEMESTER Assessment task Major exam I Major exam II Final exam Practical exam Total Marks 15 15 40 30 100 Introduction TERMS Substance abuse Taking a drug or any substance for a non-therapeutic or non-medical effect. Drug addiction= Substance dependence "When an individual persists in use of alcohol or other drugs despite problems related to use of the substance Tolerance can be defined as the phenomenon of decreased effect with prolonged exposure to a drug. • “Abused drugs” create “artificially” pleasurable experiences for the brain by interfering with the normal activities of “neurotransmitters” or the chemicals that send “chemical information” from one neuron (brain cell) to another. Major Neurotransmitters: 1. Norepinephrine – chemical messenger to cause us to protect ourselves when we are angry or afraid, the fight-or flight responses. 2. Dopamine – chemical messenger for pleasure. 3. Endorphins – chemical messengers for relieving pain and stress – natural opiate. 4. Gamma-aminobutyric Acid (GABA) Is one of the brain’s principal neurotransmitters, being particularly involved in the inhibition of stimulation. GABA is involved in coordination and the function of the brain’s systems, which allow us to “think” and “make choices.” Depressants DEPRESSANTS (DOWNERS) Slow down the central nervous system. At low doses: produce a feeling of calm, relax muscles, relieve feelings of tension and worry, and drowsiness. At higher doses: some produce sever intoxication, unconsciousness, coma and death. Examples: Alcohol, solvents/inhalants Cannabis (also belongs to hallucinogen drug class) Opioids (opium, pethadine, methadone, heroin) Prescribed tranquilizers : Benzodiazepines (eg valium) Sleeping pills: Benzodiazepines and Barbiturates GHB (gamma-hydroxybutyrate) Depressants :Alcohols Alcohol • Alcohol in beverages is ethyl alcohol. • Amount of alcohol in beer and wine is usually described as a percentage of the total volume. • Synthesized or produced naturally by fermentation • C6H12O6→ 2(CH3-CH2-OH) + 2CO2 • 1 glass wine= 1 shot of whiskey= 12 beer ALCOHOLIC BEVERAGES AND THEIR ALCOHOL EQUIVALENCIES Copyright © 2010 Pearson Education, Inc. Alcohol is a depressant drug stimulating GABA – gammaaminobutyric acid – which is one of the brains principal neurotransmitters and therefore gives an overall depression of brain function. Copyright Alcohol Medical Scholars Program PHARMACOKINETICS: ABSORPTION Rapidly absorbed primarily from duodenum Rate of absorption is extremely variable Peak blood alcohol concentration (BAC) depends on: Amount and alcohol concentration of beverage Rate of drinking Food consumption and composition Copyright Alcohol Medical Scholars Program DISTRIBUTION Volume of distribution = Total Body Water Gender Differences in body composition Copyright Alcohol Medical Scholars Program METABOLISM Metabolism 90-98% Alcohol metabolized in liver Alcohol Aldehyde Acetaldehyde Acetate dehydrogenase dehydrogenase Accumulation of acetaldehyde associated with headache, gastritis, nausea, dizziness (hangover) Short term effects • Small doses: euphoria, drowsiness, dizziness, flushing, release of inhibitions and tensions. • Larger doses: slurred speech, staggering, double vision. • Very large doses: death. • Alcohol should not be ingested simultaneously with other central nervous system depressants. 20 Copyright Alcohol Medical Scholars Program ALCOHOL-DRUG INTERACTIONS Illicit drugs (e.g., cocaine, heroin) Prescription drugs (e.g., benzodiazepines, metronidazole) Over-the-counter drugs (e.g., acetaminophen) Rx Long-Term Effects • Alcohol affects the immune, endocrine, and reproductive systems. • It can cause neurological damage, including dementia, blackouts, seizures, and hallucinations. • Various cancers are associated with heavy drinking. • It can result in hepatitis, chronic gastritis, hypertension, cirrhosis of the liver, and coronary heart disease. • the third leading cause of birth defects and mental retardation among newborns. Characteristics Growth retardation Facial malformations Small head Greatly reduce intelligence Alcohol abuse occurs when there are ongoing negative consequences from drinking. Alcohol dependence, or alcoholism, is more severe and occurs when people have problems stopping drinking. WITHDRAWAL SYMPTOMS Chronic drinkers are likely to become physically and psychologically dependent. Sleeplessness Sweating Nausea and vomiting Tremors Seizures Hallucination Death Disulfiram is an inhibitor of aldehyde dehydrogenase leading to nausea, dizziness, headache and flushing, making the entire drinking experience very aversive, and thus decreasing the desire to drink. Naltrexone (Revia) is approved for the treatment of alcoholism. It is an opioid antagonist. It has been shown to be useful in decreasing craving for alcohol, which is associated by its ability to block opioid function. Acamprosate acts by stimulating the GABA inhibitory system and antagonizing the glutamate excitatory system, thus decreasing drinking. Benzodiazepines are used primarily in the treatment of the hyperexcitability, including convulsions and hallucinations, during withdrawal.