Week 3 - Types of drugs Flashcards
What is pharmokinetics?
What the body does to the drug. It is to do with movement, absorption and how the drug moves through the body/ ways in which the drug is delivered to the body. Absorption can be via the skin, oral, smoked or injected.
Drugs have short vs long half life. E.g. nicotine is needed regularly.
Define pharmacodynamics.
What the drug does to the body. The force of the drug; how it effects you and what it does to the body. E.g. dependence, tolerance, withdrawals, cross-dependence, agonist (increases stimulation), antagonist (decreases stimulation), dopamine (releases neurotransmitters)
What are the different drug classes?
Depressants = slows down body. Benzodiazepine, alcohol, heroin.
Stimulants = speeds body up, e.g. cocaine. Accelerate activity in the nervous system.
Hallucinogens = affect perception e.g. mushrooms, LSD
What is nicotine?
A stimulant:
Dopamine agonist - reinforcing
Glutamate agonist - stimulant
Short term effect, small half-life, highly addictive
What are the pharmacodynamics of methamphetamine?
Significantly enhances dopamine (extreme agonist) and norepinephrine
Common effects: speeding up bodily functions
Reduced appetite, awake and alert .
Health effects: Risk of high blood pressure, rapid heart beat
Psycho-pathology: anxiety and tension, amphetamine psychosis
What are the most widely used depressants?
Alcohol and benzos
Benzodiazepines (pills i.e. valium)
Cannabis
Narcotic (i.e. heroin)
Depressants slow down the body and activity of the brain.
What are the commonly referred to opioids?
Opioids (heroin, fentanyl)
Depressant; opium poppy
Receptors - pain relief; endorphins
Affects dopamine (reward effects)
Pain relief - physical and psychological
Overdose risk high
Common effects - feelings of wellbeing/ euphoria/ pinpoint pupils
Long term effects = slows everything down, malnourishment, overdose biggest risk
Naloxone (Narcan) = reverses effects of OD from opioids
What is EPS?
EPS - emerging psychoactive substances
Similar metabolic structures - mimics effects, synthetic
Are rates of drug use increasing?
The average age of drug use is increasing, smoking rates are decreasing, use of meth is declining (however ice is increasing),
What are the two major harms of psychoactive drugs?
Toxicity = immediate effect of the drug. It occurs when drugs that are toxic at high blood concentrations are consumed at rates that exceed the capacity of the body to break the drug down/ excrete the drug.
Dependence = delayed effect linked to long term harms
What drugs are classified as stimulants?
Amphetamines (speed)
Cocaine
Nicotine
Caffeine
What drugs are classified as hallucinogens?
LSD (acid) Ecstasy (MDMA) Cannabis PSP (angel dust) Magic mushrooms
Define biotransformation
- The way in which the drug is altered by the body to make it more active or inactive
What are the 5 important components of pharmokinetics?
- Absorption - rate at which drug enters the blood stream. Drugs absorbed through small intestine must first pass through the liver before it reaches other organs. Nicotine is absorbed through the inside of the cheek and through the lining of the lungs.
- Distribution - depends on the amount of blood flowing to each organ, and the solubility of the drug.
- Volume of distribution - space occupied by a drug within the body. Proportional to its concentration in different tissues i.e. the brain, that contain receptors. Receptors = body’s mailboxes that receive messages and can alter rate at which a function occurs (e.g. pain or pleasure).
- Half-life = time it takes for the drug to reduce its concentration in the bloody by 50%. Drugs with a short half-life & duration of action are more likely to be abused.
- Metabolism and excretion = kidney is the most important organ for eliminating water soluble drugs.
