Term
| What are the classifications of analgesics: |
|
Definition
1. narcotic analgesics (opioids)
2. non-narcotic analgesics (antipyretics) |
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Term
| Name 4 types of opioids with examples: |
|
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
|
Definition
| Specific receptors in the CNS and other tissues. |
|
|
Term
|
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: |
|
Definition
(a) Naloxone
(b) Pentazocine |
|
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Term
| 3 characteristics of naloxone: |
|
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: |
|
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: |
|
Definition
1. Has agonist action (analgesia)
2. Weak antagonist action. |
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Term
| When is pentazocine contraindicated? |
|
Definition
| With opioid agonists like morphine, can induce withdrawal symptoms. |
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Term
| 3 desirable pharmacological actions of opioids: |
|
Definition
Analgesia
Sedation
Antitussive |
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Term
| Sometimes desirable pharmacological actions of opioids: |
|
Definition
1. Constipation
2. Hypotension |
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|
Term
| Undesirable pharmacological actions of opioids: |
|
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: |
|
Definition
1. Cough (codeine only)
2. Pain (analgesic effect)
3. Anxiety.
4. Diarrhea (opium only)
5. Opioids dependence. (Methadone only) |
|
|
Term
| Which are the strongest known analgesics? |
|
Definition
|
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Term
| Dose of opioids as analgesics: |
|
Definition
| Variable dose with no upper limit. |
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Term
| What types of pain are treated by opioids? |
|
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? |
|
Definition
| To avoid withdrawal manifestations. |
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Term
| Steps of inhibition of pain impulse with opioids: |
|
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
|
Definition
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Term
| Treatment of opioid dependence: |
|
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 |
|
Definition
• Pinpoint pupils (PPP)
• Hypoventilation: slow, shallow respiration
• Hypotension and bradycardia
• Flaccid muscles |
|
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Term
| Acute opioid toxicity: Severe/late |
|
Definition
Severe respiratory depression → respiratory arrest
• Severe cardiovascular depression
• Seizures (with pethidine overdose)
• Coma |
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Term
| Treatment of acute opioid toxicity: |
|
Definition
Naloxone (antidote):
• Reverses toxic manifestations
• Shorter half-life → repeat dose
– General supportive measures |
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