5PY010/UM1: Therapeutic Pharmacology Flashcards
What plant is opium extracted from?
Opium is extracted from the poppy plant, Papaver somniferum.
What endogenous ligands were discovered during the search in 1972?
The endogenous ligands discovered were opioid peptides: dynorphin, b-endorphin, leu-enkephalin, and met-enkephalin.
What was the significance of the discovery of opioid peptides?
The discovery of opioid peptides led to the identification of specific opioid receptors on cell membranes in the central and peripheral nervous systems
Where are opioid receptors located in the body?
Opioid receptors are found on the membranes of cells both in the central nervous system (CNS) and the periphery.
What did Hippocrates refer to in 460 BC, and how did he describe its medical use?
Around 460 BC, Hippocrates referred to opium, describing it as a drug with analgesic properties, meaning it could relieve pain.
When was opium introduced to Britain, and what form was it commonly taken in?
Opium was introduced to Britain around the end of the 17th century and was commonly taken orally as ‘tincture of laudanum.’
What was the original use of heroin when it was first marketed?
Heroin was originally marketed as a cough syrup for both adults and children.
What were the potential risks associated with the use of hypodermic syringes for administering opioids?
The use of hypodermic syringes for administering opioids increased the risk of rapid addiction, as the drug entered the bloodstream quickly, leading to a more intense and immediate effect compared to oral administration.
What is the primary active ingredient in opium, and what are its main effects?
The primary active ingredient in opium is morphine, which has powerful analgesic (pain-relieving) and sedative effects.
How does the potency of heroin compare to morphine?
Heroin is estimated to be about 2-3 times more potent than morphine, meaning that smaller doses of heroin are needed to achieve similar effects.
What is the definition of “opiate”?
An opiate is an old term used for synthetic (non-peptide) drugs that have morphine-like actions.
How does the term “opioid” differ from “opiate”?
The term “opioid” encompasses anything with morphine-like actions, including both endogenous (naturally occurring) and synthetic agents, while “opiate” refers specifically to synthetic drugs.
What is the legal definition of a “narcotic”?
In legal terms, a narcotic is an addictive drug subject to illegal use, often referring to substances that induce numbness, stupor, insensibility, or sleep, particularly opioids.
Why is the term “narcotic” often used specifically for opioids?
The term “narcotic” is commonly used for opioids because they induce sedation and pain relief, leading to insensibility, and are associated with potential for abuse and dependence.
What is the primary medical use of opioids?
Opioids are primarily used as analgesics for the effective management of acute and chronic pain.
In addition to pain relief, what other psychological effect can some opioids have?
Some opioids, like morphine, can reduce the psychological (affective) response to pain, helping to alleviate the emotional distress associated with it.
What type of pain can opioids be particularly useful for treating, other than acute and chronic pain?
Opioids can be particularly useful in treating dull, visceral pain.
How do nociceptive receptors relate to the sensation of pain?
Tissue damage stimulates nociceptive receptors, which send pain signals through primary afferent neurons to the dorsal horn of the spinal cord.
What is the role of the dorsal horn of the spinal cord in pain signaling?
The dorsal horn of the spinal cord is where nociceptive signals are relayed to neurons that further transmit pain signals to the brain.
Which part of the brain is responsible for processing pain signals?
Pain signals are relayed to the sensory cortex in the thalamus for processing.
What is the difference between nalophine and morphine regarding their analgesic effects?
Nalophine acts only as an analgesic, while morphine can also reduce the psychological response to pain, providing both physical and emotional relief.
Describe the process through which pain signals are transmitted to the brain.
Pain signals are generated by nociceptive receptors, transmitted via primary afferent neurons to the dorsal horn of the spinal cord, and then relayed to the sensory cortex in the thalamus.
What effect do opioids/national opioids have on neuronal activity in the CNS?
Opioids reduce neuronal activity in the CNS by binding to opioid receptors, leading to decreased pain perception and inducing analgesia.
What are the three main types of opioid receptors?
The three main types of opioid receptors are mu (μ), delta (δ), and kappa (κ) receptors.
What type of receptors are opioid receptors classified as?
Opioid receptors are classified as G-protein coupled receptors (GPCRs)
How do opioid receptors affect adenylyl cyclase activity?
Opioid receptors inhibit adenylyl cyclase activity, which leads to a reduction in the intracellular concentration of cyclic AMP (cAMP).
What is the significance of reducing cAMP levels in cells?
: The reduction in cAMP levels affects various cell functions,
In addition to inhibiting adenylyl cyclase, how do stimulated opioid receptors influence neuron function?
Stimulated opioid receptors exert inhibitory actions on neuron function by affecting ion channels, which can decrease neuronal excitability and reduce pain perception.
: How do mu (μ) and delta (δ) opioid receptors affect potassium (K+) channels in neurons?
Mu (μ) and delta (δ) opioid receptors cause potassium (K+) channels to open.
How does hyperpolarization impact the ability of a neuron to depolarize?
Hyperpolarization makes it harder for the neuron to depolarize because a larger change in membrane potential is required to reach the threshold for action potential generation.
What is the overall effect of mu (μ) and delta (δ) opioid receptor activation on neuronal excitability?
The activation of mu (μ) and delta (δ) opioid receptors reduces neuronal excitability by causing hyperpolarization and increasing the threshold for depolarization.
Explain the mechanism by which hyperpolarization reduces pain sensation in the context of opioid receptor activation.
By causing hyperpolarization, mu (μ) and delta (δ) opioid receptor activation decreases the likelihood of action potentials firing in pain pathways, thereby reducing the transmission of pain signals to the brain.
How do kappa (κ) opioid receptors affect N-type calcium (Ca2+) channels?
Kappa (κ) opioid receptors inhibit the opening of N-type calcium (Ca2+) channels on the neuronal membrane.
What is the consequence of inhibiting N-type Ca2+ channels on neuronal function?
Inhibiting N-type Ca2+ channels reduces the influx of calcium ions (Ca2+) into the neuron, leading to a decrease in neurotransmitter release at the synapse.
