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Which of the following foods is NOT typically associated with high levels of tyramine?
What is a common adverse drug reaction (ADR) associated with St John’s Wort?
Which neurotransmitter mechanism is primarily inhibited by reboxetine?
What is a significant clinical consideration regarding antidepressant use in individuals under 25?
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Which of the following correctly identifies a property of agomelatine?
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What is the primary mechanism by which tapentadol provides analgesic effects?
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How does naloxone function to counteract oxycodone effects when injected?
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What is a significant issue regarding the oral administration of naloxone?
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Which of the following is an indication for the use of paracetamol?
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In what way can combination therapy involving paracetamol and opioids be beneficial?
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What type of pain is tapentadol particularly effective in treating?
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What adverse event may result from an overdose of paracetamol?
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What effect does naloxone have when taken orally compared to injected?
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What condition is associated with an increased risk during the early phase of treatment with certain antidepressants?
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What is serotonin syndrome primarily caused by?
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Which class of antidepressants is known to block the reuptake of both serotonin and noradrenaline?
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Which of the following is a common side effect of Duloxetine?
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What adverse drug reaction is particularly associated with Tricyclic antidepressants?
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What condition can Duloxetine specifically help to treat?
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What mechanism do SNRIs use to exert their effects?
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Which of these is NOT a common side effect of Sertraline?
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Which of the following can occur as a result of withdrawal from certain medications?
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What is a serious potential effect of Tricyclic antidepressant overdose?
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What are the two main pathways through which paracetamol is usually processed in the liver?
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What happens to NAPQI during a paracetamol overdose?
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What role does glutathione play in the metabolism of NAPQI?
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What is the primary consequence of NAPQI accumulation in hepatocytes during an overdose?
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How does activated charcoal assist in treating paracetamol overdose?
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Which enzyme system is involved in the metabolism of paracetamol into NAPQI during an overdose?
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What is the potential severe outcome of paracetamol overdose if not treated?
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Which property of local anesthetics allows them to block action potentials?
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What is a common effect of the depletion of glutathione stores in the context of paracetamol overdose?
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In the event of paracetamol overdose, which cellular component is primarily affected by NAPQI binding?
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What effect does inflammation have on the efficacy of local anesthetics?
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Which type of bond characterizes ester bond local anesthetics?
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What is the mechanism that affects the efficacy of local anesthetics during painful procedures?
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What is the main factor distinguishing ester and amide local anesthetics?
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Which local anesthetic is most likely to have a longer duration of action?
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What is a common adverse drug reaction associated with local anesthetics?
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Which of the following statements about local anesthetic metabolism is true?
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Which local anesthetic is known for a shorter duration of action?
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In what situation is the concept of use-dependence particularly critical?
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What is a primary characteristic of local anesthetics that end in -caine?
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Study Notes
Opioid-like Analgesia
- Tapentadol is an opioid agonist with noradrenaline reuptake inhibitor actions
- It treats nociceptive or acute pain
- Increasing noradrenaline levels in the synapse modulates pain transmission
- It contributes to analgesia of neuropathic pain
Opioid Overdose
- Naloxone is a mu-receptor antagonist used to treat opioid overdose
- It can be injected, administered via a nasal spray or taken in combination with controlled-release oxycodone tablets
- When opioids like crushed oxycodone are injected alone, they rapidly reach the brain causing a quick onset of effects including euphoria.
- Oxycodone-naloxone tablets have been designed to stop oxycodone tablets from being crushed in opioid abuse situations
- Injection of oxycodone-naloxone combination does not result in euphoria because naloxone antagonizes injected oxycodone
- When swallowed, naloxone undergoes extensive first-pass metabolism in the liver, meaning that a large proportion of naloxone is inactivated before it can enter the bloodstream and reach the brain.
- Orally administered naloxone has very poor bioavailability, meaning that it does not block oxycodone’s effect, but theoretically blocks its constipatory effects
Paracetamol
- Acts on the cyclooxygenase enzyme (likely COX-3) to provide analgesic and antipyretic effects without anti-inflammatory action
- It is used for mild to moderate pain
- It is also used for fever reduction
- Can be used alongside NSAIDs
- Synergistic with opioids, therefore allowing lower opioid doses to gain the same perceived level of pain relief
- Overdose can arise from intentional harm or accidentally
- In an overdose, paracetamol metabolism cannot occur fast enough.
- Normally, paracetamol is safely processed in the liver through two main pathways — glucuronidation and sulfation — which convert it into non-toxic, water-soluble compounds that are excreted in the urine.
- When an overdose of paracetamol occurs, these primary pathways become saturated, and more of the drug is metabolized by the cytochrome P450 enzyme system (specifically CYP2E1) into NAPQI.
- Under normal conditions, NAPQI is rapidly detoxified by conjugation with glutathione, a protective antioxidant, forming a non-toxic compound that is safely excreted.
- In a paracetamol overdose, glutathione stores are depleted
- Once depleted, NAPQI accumulates in the liver and begins to covalently bind to cellular proteins and lipids, causing oxidative stress. This results in cellular damage, primarily in hepatocytes, leading to liver necrosis, and in severe cases, acute liver failure.
- Activated charcoal can help by absorbing paracetamol in the gastrointestinal tract, reducing the amount that enters the bloodstream and is metabolized into NAPQI.
Local Anaesthetics
- Local anaesthetics block voltage-dependent sodium channels which are important for initiation and propagation of an action potential
- They are weak bases, meaning they are mostly ionized at physiological pH
- In inflamed tissues (which are more acidic), they become more ionized, reducing their effectiveness
- This is why local anaesthetics may not work as well in inflamed or infected tissues
Use-Dependence
- The concept of use-dependence is not as crucial in a biopsy where there is no ongoing pain as it would be in the case of chronic pain or hyperactive nerves
- During the procedure, once the nerves begin to fire in response to tissue trauma, use-dependence comes into play.
- The local anaesthetic will be even more effective at blocking the pain signals from nerves that are repeatedly firing as the procedure progresses
Types of Local Anaesthetics
- All local anaesthetics end in the suffix, -caine.
- All possess an aromatic ring structure with an amide side chain.
- Local anesthetics are distinguished by the presence of an ester bond or amide bond.
Ester bond local anaesthetics
- Metabolised by non-specific pseudocholinesterases
- Their action is shorter-lasting
- Used for local nerve block for procedures
Ester Bond Local Anaesthetics Adverse Reactions
- ADRs are usually associated when the local anaesthetic escapes the local area, such as:
- restlessness
- anti epileptic effects
- CNS related effects
- taste disturbance
- respiratory depression
Amide bond local anaesthetics
- Distributed more widely
- Metabolised by hepatic CYP enzymes
- Their action is longer-lasting
Amide Bond Local Anaesthetics Indications
- Used for local nerve block for procedures
Amide Bond Local Anaesthetics Adverse Reactions
- Restlessness (anti-epileptic, CNS related effects, taste disturbance, respiratory depression)
Serotonin Reuptake Inhibitors (SSRIs)
- Block reuptake of 5-HT, noradrenaline and dopamine
- Escitalopram and Sertraline are examples
- ADRs: Insomnia, nausea, dizziness, anxiety, increased suicide risk during early phases of treatment, serotonin syndrome
Serotonin Syndrome
- Results from excessive accumulation of serotonin in the CNS.
- Occurs when people take medications that increase serotonin levels, particularly when multiple serotonin-enhancing drugs are used together.
- Some migraine medications and some opioids will also increase 5-HT activity.
Serotonin-Noradrenaline Reuptake Inhibitors (SNRIs)
- Block reuptake of 5-HT, noradrenaline and dopamine
- Duloxetine is used in the treatment of neuropathic pain, particularly for diabetic peripheral neuropathy
- Venlafaxine is another example
- ADRs include: Hypertension, hypercholesterolaemia, nausea, dizziness, insomnia.
Tricyclic Antidepressants
- Inhibit reuptake of noradrenaline and 5-HT, increasing the concentration of both in the synaptic cleft
- Amitriptyline is an example
- ADRs include: Anti cholinergic effects (constipation, dry eyes, dry mouth, orthostatic hypertension, confusion, sedation) and cardiac arrhythmias (can be lethal in overdose)
Tetracyclic Antidepressants
- Blocking pre-synaptic alpha-2 adrenoceptors inhibits noradrenaline release
- Mirtazapine is an example
- ADRs include sedation at lower doses
Foods rich in Tyramine
- These foods should be avoided with certain antidepressants
- Examples include: aged cheeses, cured meats (e.g. salami, sausages), fermented foods (e.g. soy sauce, sauerkraut), alcohol (especially red wine and beer)
Tetracyclic Antidepressants ADRS
- Sleep disturbance, dizziness, nausea, dietary restriction required.
Vortioxetine
- Inhibits reuptake and enhances 5-HT availability
- Has direct receptor activity
- Used to treat depression
Agomelatine
- Melatonin agonist, weak 5-HT serotonin antagonist
- Used to treat depression
St John’s Wort
- Herbal remedy thought to inhibit 5-HT, noradrenaline and dopamine reuptake, modulate serotonin receptors, inhibit MAO and modulate GABA and glutamate.
- Used to treat depression
- ADRs include: Dry mouth, photosensitivity, headache, palpitations
Selective Noradrenaline Reuptake Inhibitor
- Primarily blocks noradrenaline reuptake
- Reboxetine is an example
- ADRs include: Dizziness, insomnia,
General Clinical Considerations for Antidepressants
- Patient adherence to therapy is important due to delayed onset of clinical effects.
- Increased suicide risk during early treatment stages
- Concerns about use of antidepressants in people under 25 due to ongoing brain development
- Non-pharmacological treatments should be emphasised for mild-moderate depression
Drugs used in Mania
- First-line Treatment: Antipsychotics and anti-epileptics
- Antipsychotics: Antagonise dopamine and 5-HT such as Olanzapine, Quetiapine
- Anti-epileptics: Possess anti-convulsant activity such as Carbamazepine and Valproate.
Opioids
- Opioids decrease calcium ion influx at the presynaptic terminal, preventing neurotransmitter release
- Fentanyl is more potent than morphine and is used to treat severe cancer pain
- Naloxone is included with oxycodone to prevent constipation
- Chronic neuropathic pain occurs when pain persists in the absence of peripheral injury
- Chronic opioid use causes constipation
- Buprenorphine is safer than morphine at higher doses, as it has a ceiling effect on respiratory depression
- Opioid withdrawal symptoms include restlessness, sweating, and muscle aches
- Tramadol is a "dirty drug" that inhibits serotonin and noradrenaline reuptake and acts on muscarinic receptors
- Codeine is prescribed for mild to moderate pain and cough suppression
- Fentanyl patches used for severe cancer pain can cause respiratory depression
- Combining oxycodone with naloxone prevents constipation
- Paracetamol inhibits COX-3, which is responsible for its analgesic properties
- Naloxone is the antidote for opioid overdose
- Adrenaline decreases the rate of lidocaine absorption, reducing the risk of systemic toxicity
- Methadone is commonly prescribed for opioid replacement therapy
- Long-term NSAID use is associated with renal toxicity
- Tramadol can cause serotonin syndrome in combination with SSRIs
- Opioids are contraindicated in respiratory depression
- Tramadol inhibits serotonin and noradrenaline reuptake and acts as an opioid receptor agonist
- Naloxone is an opioid receptor antagonist
- Paracetamol is the most appropriate initial therapy for mild to moderate pain.
- Selective serotonin reuptake inhibitors are mainly used to treat depression and anxiety disorders
- Duloxetine is a drug used for neuropathic pain
- Methadone is used to manage opioid withdrawal symptoms
- SNRIs can cause hypertension
- Opioids decrease gastrointestinal motility through their action on mu receptors
- Morphine can cause respiratory depression
- Lidocaine is commonly used as a local anaesthetic in dentistry
- Amitriptyline is a serotonin and noradrenaline reuptake inhibitor used to manage pain
- Methadone can prolong the QT interval, a concerning adverse effect
- Paracetamol can cause liver toxicity
- Codeine can cause hypertensive crisis when combined with MAOIs
- Buprenorphine is a partial agonist at mu receptors
- Chronic opioid use causes constipation
- Naloxone is used to treat opioid overdose
- Tramadol inhibits serotonin and noradrenaline reuptake and has weak opioid receptor activity
Local Anaesthetics
- Local anaesthetics block sodium channels, preventing action potential propagation
Antidepressants
- Escitalopram inhibits serotonin reuptake
Other
- Serotonin syndrome can be caused by combining SSRIs with tramadol
Opioid Mechanism of Action
- Opioids decrease neurotransmitter release by reducing calcium ion influx at the presynaptic terminal
Fentanyl
- Fentanyl is a potent opioid for severe cancer pain
- It is more potent than morphine
Naloxone
- Naloxone is a medication used to reverse opioid overdose
- It is combined with oxycodone to prevent constipation
- Works as an opioid receptor antagonist
Neuropathic Pain
- Neuropathic pain is associated with chronic pain that persists after an initial peripheral injury has healed
Opioid Adverse Effects
- Long-term opioid use can lead to constipation
Buprenorphine for Opioid Dependence
- Buprenorphine is used to treat opioid dependence
- It is a partial opioid agonist, providing a ceiling effect on respiratory depression and reducing the risk of overdose
Antidepressants: SSRI
- Selective serotonin reuptake inhibitors (SSRIs) like sertraline are commonly used to treat depression
- SSRIs can increase the suicide risk, particularly in the early stage of treatment
Local Anaesthetics: Lidocaine
- Lidocaine is a local anaesthetic
- It blocks sodium channels, preventing action potential propagation
Opioid Withdrawal Symptoms
- Opioid withdrawal is characterized by restlessness, sweating, and muscle aches
- Constipation is not a symptom of opioid withdrawal
Tramadol
- Tramadol is a synthetic opioid analgesic
- It inhibits serotonin and noradrenaline reuptake and also activates opioid receptors
Codeine
- Codeine is used for mild to moderate pain and as a cough suppressant
Fentanyl Patches
- Fentanyl patches are commonly used for severe cancer pain
- They are associated with respiratory depression, requiring close monitoring
Local Anaesthesia
- Local anaesthetics like lidocaine block sodium channels to prevent action potential propagation
Combining Oxycodone with Naloxone
- Combining oxycodone with naloxone helps prevent constipation
Paracetamol
- Paracetamol reduces pain by inhibiting COX-3
Opioid Overdose
- Naloxone is the most appropriate treatment for opioid overdose, specifically for respiratory depression
Lidocaine with Adrenaline
- Adrenaline is combined with lidocaine to increase duration and prevent rapid absorption
Opioid Replacement Therapy
- Methadone is a common opioid used for opioid replacement therapy
Escitalopram
- Escitalopram is an SSRI that inhibits serotonin reuptake
NSAID Adverse Effects
- Long-term NSAID use can lead to renal toxicity
Serotonin Syndrome
- Tramadol can contribute to serotonin syndrome when combined with SSRIs
Opioid Contraindications
- Respiratory depression is a contraindication for opioid use in pain management
Tramadol Action
- Tramadol is an analgesic that inhibits serotonin and noradrenaline reuptake, but also activates opioid receptors.
Naloxone Action
- Naloxone acts as an opioid receptor antagonist
Initial Analgesic Therapy
- Paracetamol is generally the first-line medication for mild to moderate pain
SSRIs for Depression and Anxiety
- SSRIs are primarily used for depression and anxiety disorders
Duloxetine
- Duloxetine is a medication used for neuropathic pain
Opioid Withdrawal Management
- Methadone is a common medication to manage opioid withdrawal symptoms
SNRIs
- SNRIs can lead to hypertension
Opioids and Diarrhoea
- Opioids decrease gastrointestinal motility, helping manage diarrhoea
Morphine Adverse Effects
- Morphine is known to cause respiratory depression
Lidocaine in Dentistry
- Lidocaine is commonly used as a local anaesthetic in dentistry
Amitriptyline
- Amitriptyline treats pain by inhibiting serotonin and noradrenaline reuptake
Methadone
- Methadone is associated with QT prolongation, requiring monitoring
Liver Disease and Analgesia
- Paracetamol should be avoided in individuals with chronic liver disease due to the risk of hepatotoxicity
MAOI Interactions
- Codeine is contraindicated in patients taking MAOIs due to the risk of hypertensive crisis
Buprenorphine Action
- Buprenorphine is a partial agonist at mu receptors.
Chronic Opioid Use
- Constipation is common with long-term use of opioids
Naloxone for Overdose
- Naloxone is the primary treatment for opioid overdose
Tramadol Mechanism of Action
- Tramadol's mechanism involves weak opioid receptor activity along with serotonin and noradrenaline reuptake inhibition
Opioid Mechanism of Action
- Opioids decrease neurotransmitter release by reducing calcium ion influx at the presynaptic terminal.
Opioid Analgesia
- Fentanyl is more potent than morphine and used in severe cancer pain.
- Opioids can cause constipation which can be prevented by combining oxycodone with naloxone.
Neuropathic Pain Management
- Neuropathic pain is a type of chronic pain that persists after an initial injury has healed.
Long-Term Opioid Use
- Long-term opioid use can cause constipation.
Opioid Dependence and Replacement Therapy
- Buprenorphine is a partial agonist at mu receptors and has a ceiling effect on respiratory depression, making it safer at higher doses than full opioid agonists like morphine.
- Methadone is a commonly used opioid for replacement therapy.
Antidepressants
- Selective Serotonin Reuptake Inhibitors (SSRIs) like sertraline are used to treat depression.
- One possible adverse effect of SSRIs is an increased risk of suicide in the early phase of treatment.
Local Anaesthetics
- Lidocaine is a local anaesthetic that blocks sodium channels preventing action potential propagation.
Opioid Withdrawal
- Symptoms of opioid withdrawal include restlessness, sweating, and muscle aches but not constipation.
Tramadol
- Tramadol has numerous drug interactions and is referred to as a "dirty drug."
- It acts on opioid receptors and inhibits serotonin and noradrenaline reuptake.
Codeine
- Codeine is used for mild to moderate pain and cough suppression.
Fentanyl Patches
- Fentanyl patches are used for severe cancer pain and can cause respiratory depression.
Local Anaesthesia With Adrenaline
- Adrenaline added to lidocaine reduces the risk of systemic toxicity by slowing absorption
- Adrenaline is used in Minor surgical procedures.
NSAID Adverse Effects
- NSAIDS can have serious long-term adverse effects such as renal toxicity.
Serotonin Syndrome
- Tramadol can cause serotonin syndrome when combined with SSRIs.
Opioid Overdose
- Naloxone is an opioid receptor antagonist used to treat opioid overdose.
Initial Analgesia
- Paracetamol is the most appropriate first line treatment for mild to moderate pain.
Duloxetine
- Duloxetine is an SSRI, used to treat neuropathic pain
Opioid Withdrawal Management
- Methadone is used to manage opioid withdrawal symptoms
Serotonin-Noradrenaline Reuptake Inhibitors (SNRIs)
- SNRIs are used for chronic pain and can cause hypertension.
Opioid Action on Gastrointestinal Motility
- Opioids decrease gastrointestinal motility by acting on mu receptors in the GI tract.
Opioid Adverse Effects
- Morphine can cause respiratory depression.
Dental Anaesthesia
- Lidocaine is the local anaesthetic most commonly used in Dentistry
Amitriptyline
- Amitriptyline is a serotonin and noradrenaline reuptake inhibitor used to manage chronic pain.
Methadone
- Methadone can cause QT prolongation.
Hepatotoxicity
- Paracetamol should be avoided in patients with liver disease due to the risk of hepatotoxicity.
MAOI Interaction
- Codeine is contraindicated in patients taking MAOIs due to the risk of hypertensive crisis.
Buprenorphine
- Buprenorphine is a partial mu receptor agonist used for opioid replacement therapy.
Buprenorphine
- Buprenorphine is a partial mu receptor agonist used for opioid replacement therapy.
Naloxone
- Naloxone is the primary treatment for opioid overdose.
Tramadol
- Tramadol inhibits serotonin and noradrenaline reuptake and has weak opioid receptor agonist activity.
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Description
This quiz covers important aspects of opioid analgesia and overdose management. It focuses on the mechanisms of tapentadol as an analgesic and the role of naloxone in treating opioid overdoses. Test your knowledge on these critical topics in pain management and opioid safety.
