Term
What are the classifications of analgesics: |
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Definition
1. narcotic analgesics (opioids)
2. non-narcotic analgesics (antipyretics) |
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Term
Name 4 types of opioids with examples: |
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Definition
1. Endogenous: eg: endorphins, enkephalins, dynorphins.
2. Plant alkaloids: Morphine, codeine, thebaine.
3. Semisynthetic: Diamorphine (heroine), hydromorphine
4. Synthetic: pethidine (meperidine), methadone, fentanyl. |
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Term
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Definition
Specific receptors in the CNS and other tissues. |
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Term
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Definition
G protein-coupled receptors
Types: 1. Delta (1&2)
Kappa (1 2 and 3)
Mu (1 2 and 3) |
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Term
Name an opioid antagonist:
(b) Name a mixed opioid agonist/antagonist: |
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Definition
(a) Naloxone
(b) Pentazocine |
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Term
3 characteristics of naloxone: |
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Definition
1. Competitive opioid receptor antagonist.
2. Has no analgesic effect.
3. Causes withdrawal symptoms. |
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Term
3 therapeutic uses of Naloxone: |
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Definition
1. Treatment of opioid overdose (antidote)
2. Diagnosis and treatment of opioid dependence.
3. Should always be available when opioid agonists are given through IV route. |
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Term
2 characteristics of pentazocine: |
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Definition
1. Has agonist action (analgesia)
2. Weak antagonist action. |
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Term
When is pentazocine contraindicated? |
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Definition
With opioid agonists like morphine, can induce withdrawal symptoms. |
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Term
3 desirable pharmacological actions of opioids: |
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Definition
Analgesia
Sedation
Antitussive |
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Term
Sometimes desirable pharmacological actions of opioids: |
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Definition
1. Constipation
2. Hypotension |
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Term
Undesirable pharmacological actions of opioids: |
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Definition
1. Nausea/vomiting
2. Mental clouding. confusion, coma.
3. Tolerance.
4. Respiratory depression.
5. Physical dependence.
6. Addiction. |
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Term
Therapeutic indications of opioids: |
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Definition
1. Cough (codeine only)
2. Pain (analgesic effect)
3. Anxiety.
4. Diarrhea (opium only)
5. Opioids dependence. (Methadone only) |
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Term
Which are the strongest known analgesics? |
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Definition
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Term
Dose of opioids as analgesics: |
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Definition
Variable dose with no upper limit. |
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Term
What types of pain are treated by opioids? |
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Definition
Acute pain: post-operative.
Chronic severe:
Terminal illnesses like cancer (palliative care)
Dependence is not the issue
most annoying adverse effect? |
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Term
Why do opioids have to be stopped gradually? |
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Definition
To avoid withdrawal manifestations. |
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Term
Steps of inhibition of pain impulse with opioids: |
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Definition
Decreased presynaptic release of chemical
transmitters that are mobilized by pain
impulse.
ii. Blockade of postsynaptic effect of these
transmitters.
iii. Activation of descending inhibitory
pathways to block pain input.
iv. Decreased emotional reaction to pain by
acting on limbic system of the brain |
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Term
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Definition
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Term
Treatment of opioid dependence: |
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Definition
Methadone:
Same opioid effect, prevent withdrawal manifestations, much less dependence.
Buprenorphine:
Alternatitive to methadone
Naloxone:
Opioid antagonistic effect
Blocks drug seeking behaviour |
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Term
Acute opioid toxicity: Mild/early |
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Definition
• Pinpoint pupils (PPP)
• Hypoventilation: slow, shallow respiration
• Hypotension and bradycardia
• Flaccid muscles |
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Term
Acute opioid toxicity: Severe/late |
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Definition
Severe respiratory depression → respiratory arrest
• Severe cardiovascular depression
• Seizures (with pethidine overdose)
• Coma |
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Term
Treatment of acute opioid toxicity: |
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Definition
Naloxone (antidote):
• Reverses toxic manifestations
• Shorter half-life → repeat dose
– General supportive measures |
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