Study "SCH2105 - Module 10: drugs used to treat pain & inflammation", a flashcard deck on FORKSAI.
Define acute pain and chronic pain, highlighting their key distinguishing characteristics.
Acute pain has a sudden onset, a readily identifiable site, typical clinical manifestations, is self-limiting, and is readily corrected. In contrast, chronic pain persists for three or more months, is difficult to evaluate, treatment rarely brings complete relief, and is often accompanied by depression and a sense of hopelessness.
Distinguish between visceral and somatic pain, providing examples of their origins and typical characteristics.
Somatic pain originates from skin, muscles, bones, joints, or connective tissue, and is usually acute and well localized. Visceral pain originates from internal organs like the heart, lungs, or GI tract, and is typically a diffuse, deep, or aching pain, responding better to opioid medication.
Outline the four main processes involved in the pathway of pain transmission from peripheral stimulation to the cerebral cortex.
The four processes are Transduction (nociceptors convert stimuli to electrical signals), Transmission (impulses travel along afferents to the spinal cord and then to the thalamus via ascending pathways), Perception (thalamus sorts and sends information to the cortex for localization and full pain perception), and Modulation (signals are inhibited by descending pathways).
Which of the following neurotransmitters is NOT explicitly mentioned as being involved in nociceptive nerve pathways? A. Endogenous opioids B. Dopamine C. Noradrenaline D. Substance P
B. Dopamine. While dopamine is involved in the reward pathway and opioid addiction, it is not explicitly listed as a neurotransmitter communicating nociceptive nerve pathways in the provided notes, unlike endogenous opioids, noradrenaline, GABA, serotonin, and Substance P.
A patient presents with a deep, aching pain in their abdomen that is difficult to pinpoint. Which type of pain is this most likely to be, and what medication might be more effective for it?
This is most likely visceral pain, which originates from internal organs and is typically diffuse and deep. Visceral pain generally responds better to opioid medication compared to somatic pain.
Explain how opioid analgesics work at a cellular level to reduce pain perception and transmission.
Opioid analgesics bind to and activate opioid receptors, primarily mu (µ) receptors, in the central nervous system. This activation modulates pain perception and transmission by decreasing the release of Substance P and Glutamate from the primary afferent neuron, thereby decreasing the activation of secondary afferents.
A patient is prescribed morphine for severe acute pain. What are two common gastrointestinal side effects they might experience, and why do these occur?
The patient might experience reduced gastrointestinal motility and constipation. These effects occur because opioids activate opioid receptors in GI smooth muscles, which reduces secretions and motility while increasing sphincter tone.
Describe the primary function of mu (µ) opioid receptors and list three key physiological effects associated with their activation.
Mu (µ) receptors are primarily responsible for strong analgesia. Their activation also leads to respiratory depression, euphoria, sedation, constipation, miosis, and physical dependence.
A patient on long-term opioid therapy requires increasingly higher doses to achieve the same level of pain relief. What pharmacological phenomenon is occurring, and how does it develop?
This phenomenon is tolerance. Tolerance develops because continual exposure to the opioid changes the response of the receptors, making them less responsive, thus requiring more drug to produce the desired effect. This can be due to down-regulation of signaling mechanisms.
Which opioid receptor is associated with dysphoria and hallucinations, and what is its primary location?
The kappa (κ) receptor is associated with dysphoria and hallucinations. It is primarily located in the brain (hypothalamus and limbic system) and spinal cord.