Analgesics in Cancer Treatment Flashcards
What antidepressants are used in analgesia?
- Selective Serotonin Re-uptake Inhibitors (SSRIs) - Paroxetine, citalopram, fluoxetine, sertraline
- Serotonin and Noradrenaline Re-uptake Inhibitors (SNRIs) - Venlafaxine
What anti-epileptics are used in analgesia?
- Carbamazepine
- Gabapentin
What anaesthetics are used in analgesia?
- Lidocaine
- Ketamine
What opioids are using in alalgesia?
- Purine Agonists
- Morphine-like drugs
- Partial Agonists
- Nalorphine, Pentazocine, Cyclazocine
- Antagonists
- Naloxone, Naltrexone
How do antidepressants work for analgesia?
- SSRI - Paroxetine, Citalopram, Sertraline, Fluoxetine
- Not particularly effective for analgesia (why include it then, Tristan?)
- Appear to work well in disease environment such as in diabetes or HIV-related neuropathy.
- Both prevent the recycling of neurotransmitters and enhance the signal.
- SNRI - Duloxetine, Venlafaxine
- Highly effective for neuropathic pain (not in all patients)
- Side effects - nausea, somnolence, insomnia, dizziness, sedation, headache.
What are the contradictions and interactions for antidepressants in the use of analgesia?
- Contradictions - epilepsy, cardiac disease, diabetes, glaucoma, pregnancy/breast feeding.
- Interactions - Alcohol (increased sedation), NSAIDs/Aspirin (increased risk of CNA toxicity), increase in sedative effectiveness when given with opioid analgesics and SSRIs antagonise anticonvulsant effects of antiepileptics.
How do antiepileptics work in analgesia?
- Inhibit voltage fated Na+ and Ca+ channels.
- Inhibit glutamine, GABA and Glycine receptors.
- Inhibit action potential firing.
- Prevent impulse transmission
- Limit neuronal excitation
How does carbamazepine work in analgesia? (antiepileptics)
- For glossopharyngeal neuralgia, post-herpetic neuralgia, trigeminal neuralgia and diabetic neuropathies.
- Side effects - dizziness, diplopia, drowsiness, fatigue, nausea, hepatotoxicity, renal impairment, skin reactions, anorexia, dyspepsie, tremor.
- Cautions/contradictions - hepatic/renal impairment, cardiac disease, skin reactions, glaucoma, pregnancy, history of bone marrow depression.
How does Gabapentin work in analgesia? (antiepileptics)
- Complex regional pain syndrome, neuropathy of the face, post herpatic neuralgia, sciatic type pain neuropathy.
- Side effects - Anorexia, dyspepsia, tremor
- Cautions/contradictions - elderly, renal impairment, diabetes, pregnancy.
How is Lidocaine used in analegia? (local anaesthetic)
- Na+ chanel blocker - effective in non-cancer patients (IV)
- Side effects - CNS effects (confusion), respiratory depression, convulsions, hypotension, bradycardia.
- Cautions/Contradictions - Epilepsy, hepatic/respiratory impairment, atrial fibrillation, heart block, heart failure.
How is Ketamine used in analgesia? (anaesthetic)
- Blocks glutamine receptors
- Injectible but not favoured due to side effects.
- Side Effects - hypertension, tachycardia tremor, diplopia, myocardial depression
- Cautions/Contradictions - hypertension, angina, heart failure, aneurysms, cerebral trauma, psychotic disorders.
How do opioids work in analgesia?
- Modify the transmission of pain signals and the subjective perception of pain.
- Decrease neurotransmitter release.
- Block postsynaptic receptors.
- Activate inhibitory pathway.
- Highly effective - variety of routes.
- Side effects - nausea, vomiting, constipation, respiratory depression, hypotension, sedation
- Cautions/Contradictions - acute respiratory depression, acute alcoholism, head injury.
- Interactions - Alcohol (increases hypotensive and sedative effects), MAOI (increased CNA excitation/inhibition), SSRI/TCA (increased sedation), Carbamazepine (decreased plasma concentration of methadone), Cimetidine (ulcer healing -inhibit opioids metabolism)
Which of the following antiemetic drugs is the “drug of choice” for the treatment of Post-Operative Nausea and Vomiting (PONV) and Chemotherapy-Induced Nausea & Vomiting (CINV)?
Ondansetron
Which of the following is NOT associated with emesis?
The sympathetic pathway
Which of the following statements applies to morphine?
It can be antagonised by naloxone
Which of the following endogenous chemicals do(es) NOT have analgesic properties?
Substance P
