Term
| What is physiologic pain and how is it treated? |
|
Definition
| A defensive mechanism- natural response to tissue damage- opiates and other analgesics |
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Term
|
Definition
Injury, surgery, inflammation
Nerve damage, abnormal CNS function |
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Term
| What two factors characterize pathologic pain? |
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Definition
Spontaneous pain
Decreased pain threshold to noxious and innocuous stimuli |
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Term
| Describe descending inhibitory regulation: |
|
Definition
Origin in frontal cortex, amygdala, and cingulate cortex
Synapse on periaqueductal gray area then rostral ventromedial medulla and finally on dorsal horn cells |
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Term
| What are the major neurotransmitters of the descending inhibitory regulation pathway? |
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Definition
| 5HT, norepinephrine, glycine, GABA, and opiods |
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Term
| Where are opioid receptors found above the spinal cord? |
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Definition
| Periaqueductal gray area, rostral ventromedial medulla, hypothalamus, amygdala |
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Term
| Where are opioid receptors found in the spinal cord? |
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Definition
Dorsal horn cells
Primary afferent nociceptors |
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Term
| What are the functions of the Mu receptors? |
|
Definition
Supraspinal and spinal analgesia
Sedation and inhibition of respiration
Slow GI transit
Modulate hormones and release neurotransmitters |
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Term
| What opioid receptor(s) function in supraspinal and spinal analgesia? |
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Definition
|
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Term
| What opioid receptors cause sedation and inhibition of respiration? |
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Definition
|
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Term
| What opioid receptors cause a slowing of GI transit? |
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Definition
| Mu receptors and Kappa receptors |
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Term
| What opioid receptors modulate hormones and neurotransmitter release? |
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Definition
| Mu receptors and Delta receptors |
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Term
| What are the functions of Delta receptors? |
|
Definition
Supraspinal and spinal analgesia
Modulation of hormones and release of neurotransmitters |
|
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Term
| What are the functions of Kappa receptors? |
|
Definition
Supraspinal and spinal analgesia
Slow GI transit
Psychomimetic effects |
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Term
| What receptors have psychomimetic effects? |
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Definition
|
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Term
| What is the action cascade of opioid receptors? |
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Definition
Metabotropic and inhibitory
Coupled to Ca2+ channels (presynaptic) and K+ channels (postsynaptic)
Capable of down regulation |
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Term
| What are opioid receptors coupled to on the presynaptic neuron? |
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Definition
|
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Term
| What are opioid receptors coupled to on the postsynaptic neuron? |
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Definition
|
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Term
| What is the action of the opioid receptor activation on the postsynaptic cell? |
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Definition
| Hyperpolarization- decreases firing |
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Term
| What endogenous neurotransmitters are released from the presynaptic neuron onto the postsynaptic neuron to carry pain signals? |
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Definition
|
|
Term
| What two opiates have the most potent antitussive action? |
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Definition
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Term
| Why is dextromethorphan a better antitussive than codeine? |
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Definition
Lower adverse effect profile
Neuroprotective
Useful for neuropathic pain |
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Term
| What receptor mediates the euphoria associated with opiates, and what is the potential benefit of this effect? |
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Definition
| Mu receptors, improves quality of life and increases compliance |
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Term
| What opiates DO NOT cause euphoria? |
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Definition
|
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Term
| What class of opiates has the strongest sedative effect, and what population is most vulnerable to sedation from opiates? |
|
Definition
Phenanthrene derivates more than synthetic agents
Elderly |
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Term
| What is characteristic of the sedation from opiates? |
|
Definition
|
|
Term
| What is the MAIN PURPOSE of opiates? |
|
Definition
| Analgesia- the treatment and prevention of pain |
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Term
| Opioids are used in some non-pain conditions. What are the vascular effects of opioids? |
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Definition
Useful in acute heart failure due to hemodynamic effects, or to relieve stress in terminal chronic heart failure
Dilation of coronary arteries to increase flow |
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Term
| Explain the progression of prescribing analgesics: |
|
Definition
Start with NSAIDS, then weak opiods, then strong opiods
-consider combinations and rotation |
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Term
| What is the best way to manage opioid-resistant pain? |
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Definition
| (neuropathic pain, fibromyalgia) Antidepressents (amitryptyline) or anticonvulsants (gabapentin, carbamazepine) |
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Term
| What drug is self-administered in sub-anesthetic doses in labor? |
|
Definition
|
|
Term
| Why are opioids prescribed for acute pulmonary edema? |
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Definition
| Decrease anxiety, cardiac preload, afterload |
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Term
| What opioid is particularly useful for painful myocardial ischemia associated with edema? |
|
Definition
|
|
Term
| What should be used for acute pulmonary edema if respiratory depression is present? |
|
Definition
|
|
Term
Why are opioids useful for treating diarrhea?
What are some opioids used for this/ |
|
Definition
They reduce motility
Loperamide, Diphenoxylate
TREAT INFECTIONS PROMPTLY |
|
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Term
| What drugs are most effective on cough? |
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Definition
| Codeine, pholcodine, dextromethorphan |
|
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Term
| What is the usefulness of opioids in the context of anesthesia? |
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Definition
| Sedative, anxiolytic, and analgesic premedication before anesthesia and surgery |
|
|
Term
| What neuronal system mediates psychological dependence on opioids? |
|
Definition
Ventral Striatum
Interactions between the opioids and the dopaminergic system (nucleus accumbens) |
|
|
Term
| What are the symptoms of physical dependence on opioids? |
|
Definition
| Diaphoresis, insomnia, restlessness, abdominal cramps, nausea, vomiting, diarrhea |
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|
Term
| What is the mechanism of tolerance toward opioids? |
|
Definition
| Downregulation of receptors- thus, more drug is required to achieve an effect |
|
|
Term
| How do opioids cause respiratory depression? |
|
Definition
| Decrease sensitivity to chemosensitive neurons to PCO2 |
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|
Term
| What causes 90% of opiate deaths? |
|
Definition
|
|
Term
| What GI problems are caused by opiates and what might they be confused with? |
|
Definition
Epigastric distress and biliary colic
Can be confused with angina |
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Term
| What is the mechanism of opiate-induced GI problems? |
|
Definition
Increased tone of pyloric sphincter, decreased peristalsis
CONSTIPATION IS A COMMON SIDE EFFECT |
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Term
| What are the effects of opiates on the eyes? |
|
Definition
MIOSIS- pinpoint pupils
Diagnostic
Mediated by Mu and Kappa receptors
Involves Edinger Westphal Nucleus |
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|
Term
| What area of the CNS is involved in nausea and vomiting induced by opiates? |
|
Definition
|
|
Term
What are the general effects of opiates on the circulatory system?
What causes these effects? |
|
Definition
Hypotension and bradycardia
Impairment of sympathetic compensatory responses--> orthostatic hypotension |
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Term
| What is the mechanism of hypotension and bradycardia when rapid IV of large doses of opioids are given? |
|
Definition
| Non-specific mast cell degranulation |
|
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Term
| What opioids do not evoke histamine release? |
|
Definition
| Synthetics (meperidine, diphenoxylate, fentanyl) and short-acting opioids |
|
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Term
| What are the 4 areas that feed into the emetic center causing nausea and vomiting? |
|
Definition
Cortex- if you see something yucky
Vestibular- if you get dizzy/seasick
Chemoreceptor Trigger- if poisoned
Vagus Nerve and GI Tract |
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Term
| How is morphine excreted, and what does this mean? |
|
Definition
In the urine
Must adjust dose in renal insufficiency |
|
|
Term
| How is morphine commonly given? |
|
Definition
| IV- most effective intrathecally (into subarachnoid space) |
|
|
Term
| What is the clinical use of morphine? |
|
Definition
Acute and chronic pain
Epidural analgesia |
|
|
Term
| What are the adverse effects of morphine? |
|
Definition
| Sedation, respiratory depression, constipation, nausea and vomiting, itching (histamine release), tolerance, euphoria |
|
|
Term
| What is the connection between morphine and heroin? |
|
Definition
Heroin is metabolized to morphine
Indistinguishable if given orally
Heroin is more lipophilic and more potent than morphine |
|
|
Term
| What is the ONLY advantage of heroin over morphine? |
|
Definition
| Rapid brain penetration and rapid onset |
|
|
Term
| What is the clinical use of heroin? |
|
Definition
Acute and chronic pain
2nd or 3rd line antitussive
BRIEF AND INTENSE WITHDRAWL
DEPENDENCY |
|
|
Term
| How are codeine and morphine different? |
|
Definition
Codeine is weaker- only about 20% as strong as morphine
Causes little or no euphoria
Rarely addictive |
|
|
Term
| What is codeine used for? |
|
Definition
Oral analgesic for mild pain- headaches, back pain, migraines
Strong antitussive- used in cough mixtures |
|
|
Term
| What is the biggest side effect of codeine? |
|
Definition
| High risk of constipation |
|
|
Term
What are the two main side effects of oxycodone?
(actually, I would say 3) |
|
Definition
ADDICTION
Memory Loss
Constipation |
|
|
Term
| Name 4 synthetic opioids (that end in nyl or nil): |
|
Definition
| Fentanyl, alfentanyl, sufentanil, remifentanyl |
|
|
Term
| What are the advantages of synthetic opioids? |
|
Definition
Actions similar to morphine but
POTENT, FAST, SHORTER DURATION OF ACTION |
|
|
Term
| What 3 synthetic opioids are used in patient controlled infusion systems? |
|
Definition
| Fentanyl, alfentanyl, and sufentanyl |
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|
Term
| How does methadone differ from morphine? |
|
Definition
Long half life >24 hours
Highly tissue bound (extravascular)
Low intensity of addiction
Effective in treating heroin |
|
|
Term
| What is the mechanism of action of methadone? |
|
Definition
| Blocks K+ channels, NMDA, and 5HT receptors |
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|
Term
| What drug is given for post-operative shivering |
|
Definition
|
|
Term
| What opioid causes MYDRIASIS instead of miosis? |
|
Definition
|
|
Term
| What opioid is similar to atropine with atropine like antispasmodic effects? |
|
Definition
|
|
Term
| What drug, which causes mydriasis, is only 1/10th as potent as morphine and has higher rates of orthostatic hypotension? |
|
Definition
|
|
Term
| What drug, besides methadone, is used to treat addiction (to heroin)? |
|
Definition
|
|
Term
| What is the mechanism of action of buprenorphine? |
|
Definition
| Partial agonist at Mu receptors |
|
|
Term
| What are 2 advantages of administering buprenorphine for addiction? |
|
Definition
Mild withdrawal symptoms
Long plasma half life |
|
|
Term
| What opioid, mostly used in obstetrics, is relatively free of respiratory depression and abuse/dependence issues? |
|
Definition
|
|
Term
| What is the mechanism of action of meptazinol? |
|
Definition
Parital agonist at Mu receptors
Atropine-like actions
Short plasma half life, rapid action |
|
|
Term
| What opioid is widely used for postoperative pain, and what is its mechanism of action? |
|
Definition
Tramadol- weak Mu agonist
Weak NE reuptake inhibitor
Very effective with fewer side effects |
|
|
Term
| What opioid, devoid of analgesic properties, is given for diarrhea? |
|
Definition
| Loperamide- inhibits peristalsis |
|
|
Term
| What drug is given to block acupuncture analgesia and as an antidote for opioid overdose? |
|
Definition
Naloxone
PURE OPIOID ANTAGONIST |
|
|
Term
| What drug is given for chronic alcoholism, and why? |
|
Definition
Naltrexone- it is an opioid antagonist
-antagonizes endogenous opiates whose presence is enhanced by alcohol |
|
|
Term
| What Mu receptor antagonists that do not cross the BBB are used with opioids to limit constipation? |
|
Definition
| Methylnaltrexone and alvimopan |
|
|
Term
| Name 4 conditions that cause neuropathic pain: |
|
Definition
Trigeminal Neuralgia
Diabetic Neuropathy
Postherpetic Neuralgia
Phantom Limb Pain |
|
|
Term
| What opioids are useful in treating neuropathic pain? |
|
Definition
| Morphine, oxycodone, levorphanol, tramadol |
|
|
Term
| What are the classes of drugs used to treat neuropathic pain? |
|
Definition
| Opioids, tricyclic antidepressants, antiepileptics |
|
|
Term
| What drugs are used to treat fibromyalgia? |
|
Definition
Citalopram
Amitriptyline
Venlafaxine
Clonazepam |
|
|
Term
What is ketamine?
What is its mechanism of action?
What are the side effects? |
|
Definition
Dissociative anesthetic
NMDA antagonist
IMPAIRS MEMORY AND COGNITION |
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