Pharmacology of Antidiarrheal and Psychotropic Drugs
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Pharmacology of Antidiarrheal and Psychotropic Drugs

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Questions and Answers

What is the primary mechanism of action of Lamotrigine?

  • Blocks sodium channels (correct)
  • Increases neuronal excitability
  • Inhibits GABA receptors
  • Blocks calcium channels

    • Ethosuximide is a first-line treatment for generalized tonic-clonic seizures.

    False

    What condition is associated with gum hyperplasia as a side effect of certain anticonvulsants?

    Lamotrigine

    Ethosuximide affects _______ channels to help control absence seizures.

    <p>T-type calcium</p> Signup and view all the answers

    Match the following medications with their primary use:

    <p>Lamotrigine = Control epileptic events Ethosuximide = First-line treatment for absence seizures Gum hyperplasia = Side effect of certain anticonvulsants</p> Signup and view all the answers

    What type of receptors does loperamide primarily act on?

    <p>Peripheral mu receptors</p> Signup and view all the answers

    Loperamide has significant central nervous system effects.

    <p>False</p> Signup and view all the answers

    Name a medication used to treat diarrhoea that acts on peripheral mu receptors.

    <p>Loperamide</p> Signup and view all the answers

    The primary adverse drug reactions (ADRs) of loperamide include physical dependence, respiratory depression, dysphoria, and __________.

    <p>constipation</p> Signup and view all the answers

    Which of the following is NOT an adverse drug reaction (ADR) associated with loperamide?

    <p>Nausea</p> Signup and view all the answers

    Match the following adverse drug reactions with their descriptions:

    <p>Physical dependence = Withdrawal upon discontinuation Respiratory depression = Decreased breathing effectiveness Dysphoria = Negative mood effects Constipation = Reduced GI motility</p> Signup and view all the answers

    Withdrawal symptoms occur when loperamide is suddenly discontinued.

    <p>True</p> Signup and view all the answers

    What is one of the effects of respiratory depression as an ADR of loperamide?

    <p>Decreased breathing effectiveness</p> Signup and view all the answers

    What happens when MAO-A is inhibited?

    <p>Tyramine builds up in the bloodstream</p> Signup and view all the answers

    Elevated tyramine levels can lead to severe hypertension.

    <p>True</p> Signup and view all the answers

    What is a potential consequence of elevated tyramine levels?

    <p>hypertensive crisis</p> Signup and view all the answers

    Inhibition of MAO-A leads to an excessive release of __________.

    <p>noradrenaline</p> Signup and view all the answers

    Match the conditions with their outcomes:

    <p>MAO-A inhibition = Tyramine buildup Elevated tyramine = Excessive noradrenaline release Excessive noradrenaline = Severe hypertension Severe hypertension = Hypertensive crisis</p> Signup and view all the answers

    Which of the following can occur as a result of MAO-A inhibition?

    <p>Tyramine accumulation</p> Signup and view all the answers

    A hypertensive crisis caused by elevated tyramine levels is not life-threatening.

    <p>False</p> Signup and view all the answers

    What type of crisis can occur due to elevated levels of noradrenaline?

    <p>hypertensive crisis</p> Signup and view all the answers

    When tyramine builds up, it can cause an excessive release of __________.

    <p>noradrenaline</p> Signup and view all the answers

    What is a direct result of excessive release of noradrenaline?

    <p>Severe hypertension</p> Signup and view all the answers

    What is lithium carbonate primarily used for?

    <p>Prophylaxis of bipolar disorder</p> Signup and view all the answers

    Lithium carbonate takes about three weeks to become effective.

    <p>False</p> Signup and view all the answers

    What are some common adverse drug reactions (ADRs) associated with lithium carbonate?

    <p>Cardiac dysrhythmia, convulsions, hypothyroidism, diarrhoea</p> Signup and view all the answers

    Lithium carbonate substitutes itself for __________ ions in the body.

    <p>sodium</p> Signup and view all the answers

    Match the following adverse drug reactions with their descriptions:

    <p>Cardiac dysrhythmia = Irregular heartbeat Convulsions = Seizures Hypothyroidism = Low thyroid hormone levels Diarrhoea = Frequent, loose stools</p> Signup and view all the answers

    Why is lithium carbonate considered a highly toxic drug?

    <p>It has a narrow margin of safety.</p> Signup and view all the answers

    Anxiety is an abnormal response to perceived threats.

    <p>False</p> Signup and view all the answers

    List one physiological response associated with anxiety.

    <p>Autonomic reflexes, arousal, alertness, or corticosteroid secretion.</p> Signup and view all the answers

    ADRs of lithium carbonate include __________ and hypothyroidism.

    <p>cardiac dysrhythmia</p> Signup and view all the answers

    Which of the following is NOT an adverse drug reaction of lithium carbonate?

    <p>Headaches</p> Signup and view all the answers

    Which type of seizure involves high-frequency, chaotic, and sharp electrical discharges followed by rhythmic, larger-amplitude spikes?

    <p>Generalized Tonic-Clonic Seizure</p> Signup and view all the answers

    Partial seizures always involve the entire brain.

    <p>False</p> Signup and view all the answers

    What does the term 'spike-and-wave discharges' signify in the context of seizures?

    <p>Generalized Absence Seizure (Petit Mal)</p> Signup and view all the answers

    The mechanism of action that involves enhancing GABA activity is meant to reduce ____ transmission.

    <p>impulse</p> Signup and view all the answers

    Match the type of seizure with its characteristic description:

    <p>Generalized Tonic-Clonic Seizure = Involves the entire brain, characterized by violent muscle contractions. Generalized Absence Seizure = Brief loss of consciousness with spike-and-wave discharges. Partial Seizure = Localized irregular electrical activity in a specific area of the brain. Normal EEG = Low amplitude and regular waveforms indicating a non-seizure state.</p> Signup and view all the answers

    Which of the following options is NOT a mechanism of action for anti-convulsants?

    <p>Stimulate serotonin release</p> Signup and view all the answers

    The EEG pattern of a normal brain shows high-frequency, irregular activity.

    <p>False</p> Signup and view all the answers

    What are the symptoms associated with a generalized absence seizure?

    <p>Brief loss of consciousness and subtle movements such as eyelid fluttering.</p> Signup and view all the answers

    During the clonic phase of a generalized tonic-clonic seizure, the EEG shows ______ spikes.

    <p>larger-amplitude</p> Signup and view all the answers

    Which electrode position is associated with the occipital region in the EEG?

    <p>O</p> Signup and view all the answers

    What type of seizure is characterized by high-frequency, chaotic, and sharp electrical discharges initially, followed by rhythmic, larger-amplitude spikes?

    <p>Generalized Tonic-Clonic Seizure</p> Signup and view all the answers

    A generalized absence seizure is characterized by brief loss of consciousness without significant muscle movement.

    <p>True</p> Signup and view all the answers

    What is the main characteristic of EEG activity during a partial seizure?

    <p>Irregular electrical activity in a localized region</p> Signup and view all the answers

    The EEG pattern during a generalized absence seizure consists of ________ discharges.

    <p>spike-and-wave</p> Signup and view all the answers

    Match each anti-convulsant mechanism of action with its description:

    <p>Enhance GABA activity = Reduces impulse transmission Inhibit sodium-channel signalling = Used for treating generalized tonic-clonic seizures Block calcium channels = Helps control absence seizures Inhibit glutamate activity = Decreases excitatory neurotransmission</p> Signup and view all the answers

    Which of the following characteristics is true about Fentanyl?

    <p>It is extremely potent.</p> Signup and view all the answers

    Oxycodone has a longer half-life than morphine.

    <p>True</p> Signup and view all the answers

    What is the primary use of Methadone in opioid replacement treatment?

    <p>It is used to manage serious dependence on opioids.</p> Signup and view all the answers

    Fentanyl is classified as an __________ type of medication.

    <p>opioid</p> Signup and view all the answers

    Match the following drugs with their specific characteristics:

    <p>Oxycodone = Longer half-life than morphine Fentanyl = Extremely potent Methadone = Used in opioid replacement therapy Heroin = A common drug of misuse</p> Signup and view all the answers

    What key feature distinguishes Methadone from other opioids?

    <p>It helps in controlled withdrawal due to longer half-life.</p> Signup and view all the answers

    Fentanyl should be used as a first-line treatment for all pain situations.

    <p>False</p> Signup and view all the answers

    Describe one advantage of using Methadone in treating opioid dependence.

    <p>It provides a gradual withdrawal due to its longer half-life.</p> Signup and view all the answers

    What term describes insomnia that lasts for weeks or more?

    <p>Chronic</p> Signup and view all the answers

    Stress can be a contributing factor to insomnia.

    <p>True</p> Signup and view all the answers

    Name one type of drug used in the treatment of insomnia.

    <p>Z-drugs</p> Signup and view all the answers

    GABA is the brain's primary __________ neurotransmitter.

    <p>inhibitory</p> Signup and view all the answers

    Match the following insomnia factors with their impacts:

    <p>Stress = Can exacerbate insomnia Medical conditions = May disrupt sleep patterns Psychiatric disorders = Associated with chronic insomnia Lifestyle habits = Often leads to acute insomnia</p> Signup and view all the answers

    Which of the following best describes the action of Z-drugs?

    <p>Enhancing GABA activity</p> Signup and view all the answers

    Dependence on a drug refers to the body's adaptation to its presence.

    <p>True</p> Signup and view all the answers

    What type of insomnia lasts for a short term?

    <p>Acute insomnia</p> Signup and view all the answers

    The __________ effect of sedative drugs often leads to a reliance on them over time.

    <p>sedative</p> Signup and view all the answers

    Match the following characteristics with the appropriate insomnia drug type:

    <p>Z-drugs = Sedation enhancement via GABA Benzodiazepines = Longer duration of action Antidepressants = May improve sleep in depressed patients Melatonin receptor agonists = Regulate sleep-wake cycles</p> Signup and view all the answers

    What happens to paracetamol metabolism during an overdose?

    <p>It slows down considerably.</p> Signup and view all the answers

    Paracetamol is normally processed in the kidneys before being excreted in urine.

    <p>False</p> Signup and view all the answers

    Name the two main pathways through which paracetamol is processed in the liver.

    <p>Glucuronidation and sulfation</p> Signup and view all the answers

    Paracetamol is converted into non-toxic compounds that can be __________ in urine.

    <p>excreted</p> Signup and view all the answers

    Match the following processes with their descriptions:

    <p>Glucuronidation = A pathway of drug metabolism producing water-soluble compounds. Sulfation = A detoxification reaction commonly used by the liver. Paracetamol = A common pain reliever. Metabolism = The chemical process that converts substances in the body.</p> Signup and view all the answers

    Which of the following statements about paracetamol overdose is true?

    <p>It greatly increases the risk of liver damage.</p> Signup and view all the answers

    Paracetamol is converted into toxic compounds in normal doses.

    <p>False</p> Signup and view all the answers

    What system in the body is primarily responsible for the metabolism of paracetamol?

    <p>The liver</p> Signup and view all the answers

    In paracetamol metabolism, the liver converts it into __________ compounds.

    <p>non-toxic</p> Signup and view all the answers

    What is a key benefit of the glucuronidation pathway for paracetamol?

    <p>It converts paracetamol into non-toxic forms.</p> Signup and view all the answers

    What hormone do agonists like agomelatine mimic?

    <p>Melatonin</p> Signup and view all the answers

    Suvorexant works by increasing wakefulness in patients.

    <p>False</p> Signup and view all the answers

    What receptors do melatonin agonists bind to in the brain?

    <p>MT1 and MT2 receptors</p> Signup and view all the answers

    Orexin is a neurotransmitter produced in the ______.

    <p>brain</p> Signup and view all the answers

    Match the following sleep aids to their mechanism of action:

    <p>Agomelatine = Mimics melatonin Suvorexant = Antagonizes orexin receptors Benzodiazepines = Enhances GABA activity Non-benzodiazepine sedative-hypnotics = Increases sleep time</p> Signup and view all the answers

    What is a common adverse drug reaction (ADR) of agomelatine?

    <p>Dizziness</p> Signup and view all the answers

    The sleep-wake cycle is also known as the ______.

    <p>circadian rhythm</p> Signup and view all the answers

    MT1 and MT2 receptors are primarily associated with wakefulness.

    <p>False</p> Signup and view all the answers

    What effect can improper use of certain sleep aids have on sleep?

    <p>Worsening of sleep</p> Signup and view all the answers

    Which of the following is NOT a side effect commonly associated with sleep aids?

    <p>Increased blood pressure</p> Signup and view all the answers

    What is characteristic of a generalized tonic-clonic seizure?

    <p>High-frequency, chaotic electrical discharges followed by rhythmic spikes</p> Signup and view all the answers

    Absence seizures can be identified by spike-and-wave discharges on an EEG.

    <p>True</p> Signup and view all the answers

    Name one mechanism of action for anti-convulsants.

    <p>Enhance GABA activity, Inhibit sodium-channel signalling, Block calcium channels.</p> Signup and view all the answers

    During the clonic phase of a generalized tonic-clonic seizure, the EEG displays ______ spikes.

    <p>rhythmic, larger-amplitude</p> Signup and view all the answers

    Match the seizure type with its description:

    <p>Generalized Tonic-Clonic Seizure = Involves entire brain with violent contractions Generalized Absence Seizure = Brief loss of consciousness with zoning out Partial Seizure = Localized seizure activity, may involve specific symptoms</p> Signup and view all the answers

    Which medication is known for its ceiling effect on respiratory depression, making it safer for elderly patients?

    <p>Buprenorphine</p> Signup and view all the answers

    Tramadol is a selective drug that primarily inhibits serotonin reuptake.

    <p>False</p> Signup and view all the answers

    What type of pain is Tapentadol primarily used to treat?

    <p>nociceptive or acute pain</p> Signup and view all the answers

    Buprenorphine is classified as a __________ agonist.

    <p>partial</p> Signup and view all the answers

    Match the following medications with their characteristics:

    <p>Buprenorphine = Opioid replacement therapy Tramadol = Extremely non-selective drug Tapentadol = Noradrenaline reuptake inhibitor Morphine = Full opioid agonist</p> Signup and view all the answers

    Which of the following best describes the drug interactions associated with Tramadol?

    <p>High variability in metabolism and significant drug interactions</p> Signup and view all the answers

    The analgesic effects of Tapentadol are solely due to its opioid properties.

    <p>False</p> Signup and view all the answers

    What is a common adverse drug reaction (ADR) associated with the use of Tramadol?

    <p>uncomfortable ADRs</p> Signup and view all the answers

    What type of insomnia lasts for weeks or more?

    <p>Chronic insomnia</p> Signup and view all the answers

    Stress is a known factor that can cause insomnia.

    <p>True</p> Signup and view all the answers

    Name two types of drugs that act on GABA-A receptors in the treatment of insomnia.

    <p>Z-drugs, benzodiazepines</p> Signup and view all the answers

    The primary inhibitory neurotransmitter in the brain is called ______.

    <p>GABA</p> Signup and view all the answers

    Match the following terms related to insomnia treatment with their descriptions:

    <p>Z-drugs = Enhance activity of GABA-A receptors Sedative effect = Induces sleepiness Dependence = Body's adaptation to a drug Chronic insomnia = Lasts for weeks or more</p> Signup and view all the answers

    What is a common clinical consideration regarding the use of Z-drugs?

    <p>Used exclusively for sleep</p> Signup and view all the answers

    Dependence on drugs refers to the body's increased tolerance to a substance without any adverse effects.

    <p>False</p> Signup and view all the answers

    List one lifestyle habit that may contribute to insomnia.

    <p>Irregular sleep schedule</p> Signup and view all the answers

    Insomnia can be classified as either acute or ______.

    <p>chronic</p> Signup and view all the answers

    Which of the following is NOT a factor that can contribute to insomnia?

    <p>Regular exercise</p> Signup and view all the answers

    Which drug classification is indicated by having an 'I' before '-caine'?

    <p>Amides</p> Signup and view all the answers

    Affective disorders only include major depression.

    <p>False</p> Signup and view all the answers

    Name one risk factor for the development of affective disorders.

    <p>Age, gender, stress, or genetics.</p> Signup and view all the answers

    High-dose opioids can precipitate or exacerbate ________ by acting on different receptors.

    <p>depression</p> Signup and view all the answers

    Match the symptoms of depression with their descriptions:

    <p>Low mood = A persistent feeling of sadness Apathy = Lack of interest or enthusiasm Suicidal intent = Thoughts of ending one's life Changes in body weight = Significant loss or gain of weight or appetite</p> Signup and view all the answers

    Which neurotransmitters are involved in the chemical-imbalance model of depression?

    <p>Serotonin, noradrenaline, and dopamine</p> Signup and view all the answers

    Activation of the kappa opioid receptors can lead to feelings of well-being and happiness.

    <p>False</p> Signup and view all the answers

    What brain regions are involved in the regulation of normal affect?

    <p>Prefrontal cortex, anterior cingulate cortex, basal ganglia, limbic system, ventral tegmental area, nucleus accumbens, hypothalamus, pituitary, brainstem.</p> Signup and view all the answers

    The symptoms of depression include feelings of ________, hopelessness, and significant rumination.

    <p>worthlessness</p> Signup and view all the answers

    What is one significant effect of delta opioid receptor activation at high doses?

    <p>Emotional blunting</p> Signup and view all the answers

    What effect does suvorexant have on sleep?

    <p>It promotes sleep maintenance.</p> Signup and view all the answers

    The symptoms of a seizure are always the same regardless of the area of the brain affected.

    <p>False</p> Signup and view all the answers

    What neurotransmitter transmission is believed to be enhanced during a seizure?

    <p>excitatory amino acid transmission</p> Signup and view all the answers

    Blocking orexin receptors helps reduce _________ and promotes sleep.

    <p>wakefulness</p> Signup and view all the answers

    Match the type of adverse drug reaction (ADR) with its description:

    <p>Daylight drowsiness = Sedation during daytime. Sleep paralysis = Inability to move while falling asleep or waking. Abnormal dreams = Experiencing unusual, vivid dreams. Depression or suicidal thoughts = Possible severe mood disturbances.</p> Signup and view all the answers

    Which of the following is a potential cause of seizures?

    <p>Impaired inhibitory transmission.</p> Signup and view all the answers

    Common adverse effects of suvorexant include insomnia and increased wakefulness.

    <p>False</p> Signup and view all the answers

    What happens to electrical impulses in the brain during a seizure?

    <p>They become episodic and high-frequency discharges.</p> Signup and view all the answers

    The orexin receptors involved in wakefulness are known as OX1R and _______.

    <p>OX2R</p> Signup and view all the answers

    Which side effect is NOT commonly associated with suvorexant?

    <p>Severe anxiety</p> Signup and view all the answers

    What is the characteristic EEG pattern during a generalized absence seizure?

    <p>Spike-and-wave discharges</p> Signup and view all the answers

    In a generalized tonic-clonic seizure, the entire brain is involved.

    <p>True</p> Signup and view all the answers

    Name one mechanism of action for anti-convulsants.

    <p>Enhance GABA activity, inhibit sodium-channel signalling, or block calcium channels.</p> Signup and view all the answers

    During the tonic phase of a generalized tonic-clonic seizure, the EEG shows ________ discharges.

    <p>high-frequency, chaotic</p> Signup and view all the answers

    Match the type of seizure with its description:

    <p>Generalized Tonic-Clonic Seizure = Involves the entire brain with loss of consciousness Generalized Absence Seizure = Brief loss of consciousness with subtle movements Partial Seizure = Localized electrical activity in one part of the brain</p> Signup and view all the answers

    What symptom is often related to the chemoreceptor trigger zone (CTZ)?

    <p>Nausea and vomiting</p> Signup and view all the answers

    Tolerance to opioids can develop within 14 days of regular dosing.

    <p>True</p> Signup and view all the answers

    What effect does sedation have on patient safety?

    <p>Increased risk of falls</p> Signup and view all the answers

    Histamine release triggered by morphine may cause __________.

    <p>itching</p> Signup and view all the answers

    Match the following symptoms with their descriptions:

    <p>Nausea and vomiting = Often CTZ-related Sedation = Increases falls risk Pupil constriction = Miosis effect Histamine release = Can lead to itching and hypotension</p> Signup and view all the answers

    What is a common adverse reaction of morphine?

    <p>Bronchospasm</p> Signup and view all the answers

    Pupil constriction, also known as miosis, is a common symptom associated with opioid use.

    <p>True</p> Signup and view all the answers

    Higher doses are needed to achieve previous analgesic effects due to __________.

    <p>tolerance</p> Signup and view all the answers

    Which of these foods are rich in tyramine? (Select all that apply)

    <p>Aged cheeses</p> Signup and view all the answers

    Fermented foods do not contribute to tyramine levels.

    <p>False</p> Signup and view all the answers

    Name one type of alcohol that is particularly high in tyramine.

    <p>Red wine</p> Signup and view all the answers

    Sleep disturbances can be an adverse drug reaction (ADR) associated with __________.

    <p>tyramine</p> Signup and view all the answers

    Match the following foods with their tyramine content:

    <p>Aged cheeses = High Fresh fruits = Low Cured meats = High Vegetables = Low</p> Signup and view all the answers

    Which of the following is NOT an ADR associated with tyramine?

    <p>Increased appetite</p> Signup and view all the answers

    What dietary restrictions might be required due to high tyramine levels?

    <p>Avoidance of aged cheeses and cured meats.</p> Signup and view all the answers

    Dizziness is a common adverse drug reaction associated with tyramine.

    <p>True</p> Signup and view all the answers

    Elevated tyramine levels can cause severe __________.

    <p>hypertension</p> Signup and view all the answers

    Which of the following is primarily responsible for metabolizing tyramine?

    <p>MAO-A</p> Signup and view all the answers

    Which of the following statements about Fentanyl is true?

    <p>It is extremely potent.</p> Signup and view all the answers

    Methadone has a shorter half-life compared to Oxycodone.

    <p>False</p> Signup and view all the answers

    What is one of the uses of Methadone?

    <p>Opioid replacement treatment</p> Signup and view all the answers

    Fentanyl is NOT used outside of severe __________ pain.

    <p>cancer</p> Signup and view all the answers

    Match the opioid with its description:

    <p>Oxycodone = Longer half-life than morphine Fentanyl = Extremely potent and used for severe pain Methadone = Long half-life, used as an opioid replacement None = Not a first-line option</p> Signup and view all the answers

    Which opioid is known to block the effects of drugs like heroin?

    <p>Methadone</p> Signup and view all the answers

    Oxycodone is less potent than morphine.

    <p>True</p> Signup and view all the answers

    What is the primary characteristic of Methadone?

    <p>Long half-life</p> Signup and view all the answers

    _________ is classified as NOT a first-line medication.

    <p>Fentanyl</p> Signup and view all the answers

    Which opioid is often used in the context of serious opioid dependence treatment?

    <p>Methadone</p> Signup and view all the answers

    What is the primary mechanism of action of Reboxetine?

    <p>Blocks noradrenaline reuptake</p> Signup and view all the answers

    Increased suicide risk during early treatment stages is a notable clinical consideration.

    <p>True</p> Signup and view all the answers

    What should be emphasized for mild to moderate depression?

    <p>Non-pharmacological treatments</p> Signup and view all the answers

    The use of anti-depressants in people under _______ requires caution due to ongoing brain development.

    <p>25</p> Signup and view all the answers

    Match the following treatments for mania with their corresponding mechanisms:

    <p>Olanzapine = Antagonizes dopamine Carbamazepine = Anti-epileptic agent Quetiapine = Antagonizes 5-HT Valproate = Mood stabilizer</p> Signup and view all the answers

    Which of the following statements is true regarding Reboxetine?

    <p>It is associated with insomnia as a side effect.</p> Signup and view all the answers

    Anti-epileptic medications do not have any anti-convulsant activity.

    <p>False</p> Signup and view all the answers

    Name a common antipsychotic drug used in the treatment of mania.

    <p>Olanzapine</p> Signup and view all the answers

    The primary action of anti-psychotics in treating mania involves _______ dopamine and 5-HT.

    <p>antagonizing</p> Signup and view all the answers

    Which of the following is a concern for young individuals undergoing treatment with antidepressants?

    <p>Delayed onset of clinical effects</p> Signup and view all the answers

    Study Notes

    Antidiarrheal Medications

    • Loperamide acts on peripheral mu receptors.
    • Loperamide treats diarrhea without central nervous system effects.
    • Loperamide side effects include:
      • Physical dependence and withdrawal upon discontinuation
      • Respiratory depression
      • Dysphoria (negative mood effects)
      • Constipation (reduced GI motility)

    Monoamine Oxidase Inhibitors (MAOIs)

    • MAOIs, like phenelzine, are used to treat depression and anxiety.
    • MAOIs inhibit the enzyme monoamine oxidase (MAO-A).
    • When MAO-A is inhibited, tyramine can build up in the bloodstream.
    • Elevated tyramine levels can cause excessive noradrenaline release leading to severe hypertension (hypertensive crisis), which can be life-threatening.

    Lithium Carbonate

    • Lithium carbonate substitutes itself for sodium ions, altering action potentials and neuronal signalling.
    • Lithium carbonate reduces transmitter release.
    • Lithium carbonate is used for the prophylaxis (prevention) of difficult to treat bipolar disorder.
    • Lithium carbonate takes around two weeks to become effective.
    • Lithium carbonate has a narrow margin of safety (highly toxic drug).
    • Lithium carbonate side effects include:
      • Cardiac dysrhythmia
      • Convulsions
      • Hypothyroidism
      • Diarrhea

    Anti-Convulsants

    • Anti-convulsant medications have three mechanisms of action:
      • Enhance GABA activity.
      • Inhibit sodium channel signalling.
      • Block calcium channels.

    Lamotrigine

    • Lamotrigine blocks sodium channels of neurons that are firing excessively during seizures to reduce neuronal excitability and prevent epileptic events.

    Ethosuximide

    • Ethosuximide affects T-type calcium channels, which help propagate absence seizures.
    • Ethosuximide is used as a first-line treatment for absence seizures, especially in children.

    Anxiety

    • Anxiety is a normal response to perceived threats, associated with autonomic nervous system reflexes, arousal, alertness, corticosteroid secretion, and negative emotions.

    EEG Patterns

    • Panel A: Normal EEG shows low amplitude and regular waveforms, indicating a non-seizure state.
    • Panel B: Generalized Tonic-Clonic Seizure (Grand Mal) shows high-frequency, chaotic, and sharp electrical discharges during the tonic phase, followed by rhythmic, larger-amplitude spikes during the clonic phase.
    • Panel C: Generalised Absence Seizure (Petit Mal) shows spike-and-wave discharges, which are characteristic of brief loss of consciousness.
    • Panel D: Partial Seizure shows irregular electrical activity in a localized region, indicating a specific focus in the brain.

    Lamotrigine Side Effects

    • Gum hyperplasia (excessive growth of gum tissue)

    Opioids

    • Oxycodone has a longer half-life than morphine.
    • Fentanyl is extremely potent and not used as a first-line opioid or outside of severe cancer pain.
    • Methadone has a long half-life and is used as an opioid replacement treatment in situations of serious dependence.
      • It is a weak agonist of mu-opioid receptors.
      • It reduces induction of euphoria and cross-tolerance.
      • It blocks the effects of drugs like heroin.
      • It facilitates more controlled and gradual withdrawal.
    • In a methadone overdose, paracetamol metabolism cannot occur fast enough.
      • Normally, paracetamol is safely processed in the liver through two main pathways: glucuronidation and sulfation.
      • These pathways convert paracetamol into non-toxic, water-soluble compounds that are excreted in the urine.

    Insomnia

    • Insomnia can be acute (short-term) or chronic (lasting for weeks or more).
    • Causes of insomnia include stress, medical conditions, psychiatric disorders, and lifestyle habits.

    Drugs Used in the Treatment of Insomnia

    • Z-drugs (zolpidem and zoplicone) act on GABA-A receptors in the brain, enhancing the activity of GABA (the brain's primary inhibitory neurotransmitter).
      • This leads to a sedative effect by increasing receptor activity.
      • They are used exclusively for sleep.
      • Dependence refers to the body's adaptation to a drug, leading to physical reliance on it to function normally.
      • Z-drugs are well-tolerated compared to other sleep aids like benzodiazepines or non-benzodiazepine sedative-hypnotics.
    • Agomelatine is a melatonin receptor agonist; it mimics the action of melatonin.
      • Melatonin is a natural hormone produced by the pineal gland that regulates the sleep-wake cycle.
      • Agomelatine binds to melatonin receptors in the brain, specifically MT1 and MT2 receptors, to promote sleep onset and regulate circadian rhythms.
      • It is well-tolerated, especially compared to other sleep aids.
    • Suvorexant is an orexin receptor antagonist.
      • Orexin is a neurotransmitter produced in the brain that promotes wakefulness.
      • Suvorexant works by reducing wakefulness rather than sedating the patient.

    Common Adverse Drug Reactions (ADRs) of Insomnia Medications

    • Dizziness
    • Fatigue or drowsiness
    • Headache
    • Nausea
    • Worsening of sleep if not used properly

    Electroencephalography (EEG)

    • Panel A: Normal EEG shows relatively regular waveforms that correspond to different brain regions (F, T, and O).
      • These waveforms are low amplitude and regular, indicating a normal, non-seizure state.
    • Panel B: Generalized Tonic-Clonic Seizure (Grand Mal) demonstrates high-frequency, chaotic, and sharp electrical discharges during the tonic phase of a seizure and rhythmic, larger-amplitude spikes during the clonic phase.
      • This type of seizure involves the entire brain and is characterized by unconsciousness and violent muscle contractions.
    • Panel C: Generalized Absence Seizure (Petit Mal) shows spike-and-wave discharges (short, rapid spikes followed by slow waves), which are characteristic of absence seizures.
      • These seizures involve a brief loss of consciousness, making the person appear to "zone out" for a few seconds with subtle movements like eyelid fluttering or lip smacking.
    • Panel D: Partial Seizure shows irregular electrical activity in a localized region of the brain, indicating the focus of the seizure activity.
      • This type of seizure does not involve the entire brain, and symptoms can vary depending on the location of the focus.

    Anti-Convulsants

    • Mechanism of action:
      • Enhance GABA activity: GABA is an inhibitory neurotransmitter, so increasing its activity reduces impulse transmission.
      • Inhibit sodium-channel signalling: medications like carbamazepine, phenytoin, and lamotrigine work this way.
      • Block calcium channels: medications like ethosuximide, gabapentin, and pregabalin operate using this mechanism.

    Opioids

    • Buprenorphine is an opioid replacement therapy that comes in oral film or patch forms, its ceiling effect on respiratory depression makes it suitable for the elderly.
    • Tramadol is classified as a "dirty drug" due to its broad spectrum of actions including serotonin and noradrenaline reuptake inhibition, muscarinic and nicotinic receptor interaction, and varied metabolism which contributes to unpredictable adverse drug reactions.
    • Tapentadol is an opioid-like analgesic, this pain relief is effective for both nociceptive and acute pain.

    Local Anesthetics

    • Amide local anesthetics, such as lidocaine, contain an "I" before "-caine".
    • Ester local anesthetics, such as procaine, lack the "I" before "-caine".

    Affective Disorders

    • Affective disorders primarily affect mood and include conditions such as depression, mania, and bipolar disorder.
    • The brain regions involved in regulating normal affect include the prefrontal cortex, anterior cingulate cortex, basal ganglia, limbic system, ventral tegmental area, nucleus accumbens, hypothalamus, pituitary, and brainstem.
    • Age, gender, stress, and genetics are risk factors for developing affective disorders.

    Depression

    • Depression can range in severity from mild to moderate to major.
    • High-dose opioids can worsen or trigger depression by interacting with delta and kappa opioid receptors, both known to affect mood regulation.
    • Delta opioid receptor activation at high doses contributes to emotional blunting and mood disturbances.
    • Kappa opioid receptor activation leads to dysphoria, characterized by feelings of sadness, isolation, anxiety, and discomfort.
    • Common symptoms of depression include low mood, excessive rumination on the past, misery, apathy, hopelessness, guilt, feelings of worthlessness, suicidal thoughts, indecisiveness, loss of appetite, weight changes, and loss of libido.
    • The chemical-imbalance model of depression proposes that depression is caused by an imbalance of neurotransmitters like serotonin (5-HT), noradrenaline, and dopamine.

    Insomnia

    • Insomnia can be acute (short-term) or chronic (long-term), often caused by factors including stress, medical conditions, psychiatric disorders, or lifestyle habits.

    Drugs for Insomnia

    • Z-drugs (zolpidem, zoplicone) enhance GABA activity by acting on GABA-A receptors in the brain, causing a sedative effect and promoting sleep.
    • Suvorexant reduces wakefulness by antagonizing orexin receptors (OX1R and OX2R) in the brain, promoting sleep onset and sleep maintenance.
    • Dependence can occur with Z-drugs as the body and brain adapt to the drug over time.
    • Z-drugs have a low risk of dependence or withdrawal symptoms compared to other sleep medications.
    • Common Z-drug ADRs include daytime drowsiness, headache, abnormal dreams or nightmares, sleep paralysis, sleep-related behaviors, depression, and suicidal thoughts

    Seizures and Anticonvulsants

    • Seizures are episodic, abnormal bursts of high-frequency electrical impulses in the brain, originating from a specific focus and potentially spreading to other areas.
    • Seizures are thought to result from a combination of enhanced excitatory amino acid transmission, impaired inhibitory transmission, and abnormal electrical properties of affected neurons.
    • Seizure symptoms vary depending on the brain region affected.

    Electroencephalography (EEG) Patterns During Seizures

    • Normal EEG shows regular, low-amplitude waveforms indicating normal brain activity without seizures.
    • Generalized tonic-clonic seizures (grand mal) are characterized by high-frequency, chaotic electrical discharges in the tonic phase, followed by rhythmic, high-amplitude spikes during convulsive (clonic) phase.
    • Generalized absence seizures (petit mal) show spike-and-wave discharges on the EEG, resulting in brief loss of consciousness with subtle movements like eyelid fluttering or lip smacking.
    • Partial (focal) seizures display irregular electrical activity in a specific brain region, resulting in symptoms that depend on the location of the focus.

    Mechanism of Action for Anticonvulsants

    • Enhance GABA activity: GABA is an inhibitory neurotransmitter, increasing its activity reduces nerve impulse transmission.
    • Inhibit sodium channels: Drugs like carbamazepine, phenytoin, and lamotrigine act by inhibiting sodium channel signaling.
    • Block calcium channels: Drugs like ethosuximide, gabapentin, and pregabalin block calcium channels.

    Opioids

    • Morphine is associated with nausea, vomiting, sedation, pupil constriction, and histamine release.
    • Oxycodone has a longer half-life than morphine.
    • Fentanyl is extremely potent and not first-line for pain management.
    • Fentanyl is not used outside of severe cancer pain.
    • Methadone has a long half-life and is used for opioid replacement treatment.
    • Methadone is a weak agonist of mu-opioid receptors.
    • Methadone is used in situations with serious dependence due to its longer half-life, reduced induction of euphoria, and cross-tolerance.

    Reboxetine

    • Reboxetine primarily blocks noradrenaline reuptake.
    • Reboxetine may cause insomnia.

    General Clinical Considerations for Antidepressants

    • Patient adherence to therapy is important due to the delayed onset of clinical effects.
    • Increased suicide risk during early treatment stages.
    • Concerns about use of anti-depressants in people under 25 years old due to ongoing brain development.
    • Non-pharmacological treatments should be emphasized for mild-moderate depression.

    Drugs used in Mania

    • Anti-psychotic and anti-epileptic medicines are first-line treatment for mania.
    • Anti-psychotics antagonise dopamine and 5-HT receptors (e.g. olanzapine, quetiapine).
    • Anti-epileptics possess anti-convulsant activity.

    EEG

    • Panel A: Normal EEG shows relatively regular waveforms corresponding to different brain regions (frontal, temporal, occipital).
    • The waveforms are low amplitude and regular.
    • Panel B: Generalized Tonic-Clonic Seizure has high-frequency, chaotic, and sharp electrical discharges at the start.
    • The later stage of a generalized tonic-clonic seizure shows rhythmic, larger-amplitude spikes.
    • Panel C: Generalized Absence Seizure shows spike-and-wave discharges (short, rapid spikes followed by slow waves).
    • Panel D: Partial Seizure shows irregular electrical activity in a localized region, different from the global brain activity seen in generalized seizures.

    Anti-Convulsants

    • Anticonvulsants have three mechanisms of action:
      • Enhancing GABA activity: increasing GABA's activity reduces impulse transmission
      • Inhibiting sodium-channel signaling: carbamazepine, phenytoin, lamotrigine
      • Blocking calcium channels: ethosuximide, gabapentin, pregabalin

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