What are the four key pharmacokinetic stages?
Absorption, Distribution, Metabolism, Excretion (ADME).
What determines the intensity and duration of a drug’s effect?
Concentration at the site of action.
What is bioavailability?
The fraction of an administered dose that reaches systemic circulation unchanged.
What is the main function of the liver in drug metabolism?
Converts drugs into more water-soluble compounds for excretion.
What differentiates drug misuse from abuse?
Misuse = incorrect use of prescribed/available drugs;
abuse = intentional use for euphoria/escape.
What is the primary CNS effect of alcohol?
CNS depression via enhanced GABA and reduced glutamate activity.
How is alcohol metabolized in the body?
By alcohol dehydrogenase → acetaldehyde → acetate.
What factors affect BAC (Blood Alcohol Concentration)?
Gender, weight, rate of consumption, food intake, and metabolism.
What are the long-term effects of chronic alcohol use?
Liver cirrhosis, brain damage, hypertension, and nutritional deficiencies.
Why can alcohol withdrawal be life-threatening?
Causes seizures, delirium tremens, and severe CNS hyperexcitability.
What medication is used for alcohol dependence treatment?
Disulfiram (Antabuse), naltrexone, or acamprosate.
What is the main psychoactive compound in cannabis?
THC
What receptors does THC act on?
CB₁ (CNS) and CB₂ (peripheral/immune).
What is the function of CB₁ receptors?
Inhibit excitatory neurotransmitter release → CNS depression.
Why can’t cannabis cause respiratory depression?
No CB₁ receptors in the brainstem.
What are the long-term cognitive effects of heavy cannabis use?
Memory and concentration impairment, especially with early use.
What is “amotivational syndrome”?
Apathy and reduced ambition seen in some chronic cannabis users.
What explains cannabis’s long detection window in drug tests?
THC is lipid-soluble and stored in fat tissue.
What percentage of users develop cannabis addiction?
About 10%
What are the three main types of opioids?
- Natural (morphine)
- Semi-synthetic (heroin, oxycodone),
- Synthetic (fentanyl, methadone).
What are the three main opioid receptor types?
Mu (μ)
Kappa (κ)
Delta (δ).
What effects are mediated by μ-opioid receptors?
Analgesia
euphoria
respiratory depression
dependence.
What is the main mechanism of opioid action?
Inhibit neurotransmitter release and hyperpolarize neurons → block pain transmission.
What are the short-term effects of opioids?
Analgesia, euphoria, sedation, miosis, respiratory depression, constipation.
