test 4 Flashcards
opioids, cannabis, and hallucinogens (41 cards)
what are the active ingredients in opium?
morphine and codeine
what is opium?
naturally occurring substance derived from poppy plants
what are the two ways by which opioids are derived?
-derived directly from opium
-synthetic drug with opium-like effect
what are the 3 opioid receptors?
-µ
-δ
-κ
which opioid receptors elicit which effects?
-most pharmacological effects are derived through activating µ and δ receptors
-κ receptors elicit hallucinogenic effects
how do opioids effect the medulla?
-neurons release endogenous opioids in the medulla, which contains a high density of µ opioid receptors
-reduces nociceptive information sent to the thalamus
describe the pain pathway
- C and Aδ neurons send nociceptive (pain stimuli) information from environment to the spinal cord
-causes a release of glutamate and substance P neurons in the spinothalamic pathway
-then sends nociceptive information to thalamus, then to the somatosensory cortex (where information is processed) and the cingulate cortex (approach/avoid behavior) and amygdala (emotional response) in the limbic system
how do opioids effect the pain pathway?
-reduce glutamate and substance P (stops in the spinal cord)
-still get sensory pain but not the perception of it
what are the withdrawal symptoms of opioid use and what acute pharmacological effect is each caused by (7)?
-pain sensitivity (analgesia)
-diarrhea (constipation)
-increased blood pressure (decreased blood pressure)
-dysphoria and depression (euphoria)
-hyperthermia (hypothermia)
-restlessness (relaxation)
-hyperventilation (respiratory depression)
what are the medical uses for opioids?
-morphine and other opioid analgesics (lack significant efficacy for neuropathic (damage to nociceptive neurons) and idiopathic (pain from an unknown source) pain
-diarrhea
suppress cough reflex
how do opioids help diarrhea?
-inhibitory effects of opioid receptors in the intestinal tract
how do opioids help suppress cough reflex? what are some examples of medications?
-activate inhibitory opioid receptors
-codeine is a prescription cough syrup
-dextromethorphan in OTC medications
what are the differences between heroin and morphine?
-heroin has high lipid solubility, so it can pass the blood-brain barrier easier while morphine has poor lipid solubility
-morphine has gradual onset effects while the onset effects of heroin are rapid
what is the antagonist treatment for opioid dependence? what are two examples? Describe each.
-increased severity of withdrawal symptoms but shortened duration
-naloxone- short-acting opioid antagonist
-naltrexone- long-acting opioid antagonist and has shown to be effective but only for highly motivated individuals
what is the controlled schedule listing for marijuana?
schedule III
describe the lipid solubility of cannabis
-Δ9-THC exhibits high lipid solubility
-leads to rapid distribution into tissues, including the brain, and accumulation in fat
-Δ9-THC in fat releases slowly over time which leads to long-term pharmacological actions and long elimination rates
what are the 2 endocannabinoids?
-anandamide
-2-AG
what are the two cannabinoid receptors?
-CB1
-CB2
what are CB1 receptors?
-found throughout the brain
-Δ9-THC and anandamide have high affinity
-2-AG has weak affinity
-dense population in the eye
-leads to increased dopamine concentration in the nucleus accumbens
what are CB2 receptors?
-density found in the immune system
-exhibit inhibitory effects
describe how cannabis can cause a sense of accelerated time
-related to a reduction of activity in the cerebellum which can cause slower cognitive processing and sensory integration
explain the relationship between cannabis and lung cancer.
- cannabis smoke contains more carcinogens than tobacco cigarettes which results in a greater amount of tar in the lungs, but it contains chemicals that may limit a user’s risk of lung cancer and other cancers
-studies fail to show a relationship between cannabis and lung cancer, but they have found that cannabis can increase the risk of respiratory diseases like bronchitis and emphysema
what is dronabinol?
- oral Δ9-THC preparation
-1985- FDA-approved for sale to cancer patients experiencing nausea from chemotherapy as an antiemetic
1993- FDA approved for sale to AIDS and cancer patients to stimulate appetite
what are the arguments for making smokable medical marijuana legal?
-rapid onset
-greater ability of the patient to control effects
-other ingredients in marijuana plant may be beneficial and limit negative subjective or other behavioral effects of Δ9-THC