Psychopharmacology
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Questions and Answers

What is the mechanism of action of anticholinergic drugs?

  • Block muscarinic receptors (correct)
  • Increase serotonin availability
  • Enhance norepinephrine activity
  • Inhibit dopamine uptake

    • Which of the following is NOT a severe side effect associated with Clozapine?

  • Blood dyscrasias
  • Drowsiness
  • Weight loss (correct)
  • Hyperpyrexia

    • Which condition requires caution when prescribing Clozapine?

  • Type 2 Diabetes
  • Hypertension
  • Asthma
  • Parkinson’s disease (correct)

    • Which of the following antidepressants work by inhibiting monoamine oxidase?

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

    What is a common adverse effect of both Clozapine and certain antidepressants?

    <p>Weight gain</p> Signup and view all the answers

    What is the primary neurotransmitter affected by the monoamine theory of depression?

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

    What is a significant risk when using antipsychotic drugs without anticholinergic medications?

    <p>Extrapyramidal symptoms</p> Signup and view all the answers

    Which of the following drugs is classified as an antidepressant that selectively inhibits serotonin reuptake?

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

    What is the primary mechanism of action for tricyclic antidepressants?

    <p>Block the reuptake of noradrenaline and serotonin</p> Signup and view all the answers

    Which condition is NOT an indication for the use of tricyclic antidepressants?

    <p>Bipolar disorder</p> Signup and view all the answers

    Which of the following is a common adverse effect of tricyclic antidepressants?

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

    How do monoamine oxidase inhibitors (MAOIs) function in the body?

    <p>They bind irreversibly to monoamine oxidase</p> Signup and view all the answers

    Which of the following complications is associated with MAOI usage?

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

    Which side effect is considered rare with the use of MAOIs?

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

    What type of receptors do tricyclic antidepressants block besides noradrenaline and serotonin receptors?

    <p>Histaminergic and cholinergic</p> Signup and view all the answers

    Which of the following describes a common withdrawal symptom associated with tricyclic antidepressants?

    <p>Cholinergic rebound symptoms</p> Signup and view all the answers

    What cardiovascular effect can occur with an overdose of tricyclic antidepressants?

    <p>Prolonged QRS complex</p> Signup and view all the answers

    In patients taking monoamine oxidase inhibitors, when should the medication not be given to avoid sleep disturbances?

    <p>After 3pm</p> Signup and view all the answers

    Which adverse effect is characterized by abnormal movements of the mouth, face, and tongue, and may be irreversible?

    <p>Tardive Dyskinesia</p> Signup and view all the answers

    What is a common side effect of antipsychotics due to dopamine receptor blockade that can lead to gynecomastia and amenorrhoea?

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

    Which of the following antipsychotics is least likely to cause weight gain?

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

    Which extrapyramidal side effect presents as a motor restlessness, often confused with agitation?

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

    Which antipsychotic is particularly well-known for causing profound orthostatic hypotension?

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

    What is an infrequent but potentially fatal adverse effect associated with antipsychotics characterized by fever and muscle rigidity?

    <p>Neuroleptic Malignant Syndrome</p> Signup and view all the answers

    Which receptor blockade is primarily responsible for the endocrine effects seen with many antipsychotics?

    <p>Dopamine receptors</p> Signup and view all the answers

    Which of the following is not typically associated with metabolic syndrome as a side effect of antipsychotics?

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

    Which condition is characterized by symptoms similar to Parkinson's disease, including shuffling gait and rigidity?

    <p>Drug Induced Parkinsonism</p> Signup and view all the answers

    Which antipsychotic drug is known to have a significant effect on raising serum prolactin levels?

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

    What is a common pharmacokinetic characteristic of most antipsychotic medications?

    <p>Highly lipophilic</p> Signup and view all the answers

    Which adverse effect is typically caused by the blockade of alpha receptors and may lead to syncope?

    <p>Orthostatic hypotension</p> Signup and view all the answers

    What dosage form is NOT commonly used for antipsychotic medications?

    <p>Sublingual tablets</p> Signup and view all the answers

    Antipsychotic medications are known to enter fetal circulation and breast milk. What is a common neonatal side effect?

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

    Which atypical antipsychotic is used to treat patients who are nonresponsive to other antipsychotics?

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

    Study Notes

    Clozapine

    • Requires medical supervision and resuscitation facilities when administered.
    • Associated with severe side effects, including blood dyscrasias.
    • Other side effects include:
      • Hyperpyrexia (5%)
      • Nausea and vomiting
      • Drowsiness (40% of treated people)
      • Tachycardia
      • Hypersalivation (can cause aspiration pneumonia)
      • Weight gain
      • Seizures
      • Priapism

    Clozapine Precautions

    • Parkinson's disease
    • Epilepsy
    • Respiratory failure
    • Hypothyroidism
    • Shock
    • Closed angle glaucoma, as it can increase intraocular pressure
    • GI obstruction
    • Urinary retention
    • Low WCC or previous blood abnormality
    • Elderly patients require lower starting doses

    Anticholinergic Drugs

    • Used to treat a variety of conditions.
    • Work by blocking the action of acetylcholine, a type of neurotransmitter.
    • Inhibit involuntary muscle movements and various bodily functions.
    • Commonly used in psychiatric practice to counteract extrapyramidal symptoms secondary to antipsychotic drugs.
    • Some extrapyramidal side effects (e.g. drug-induced Parkinsonism, akinesia, dystonia) may be reduced by anti-parkinsonian drugs with anticholinergic action.
    • Block muscarinic receptors and reduce the relative excess of cholinergic activity that accompanies dopamine deficiency.

    Anticholinergic Drugs - List

    • Benztropine
    • Benzhexol
    • Biperidin
    • Orphenadrine

    Antidepressants - Monoamine Theory of Depression

    • Depression is caused by a functional deficit of monoamine transmitters at certain sites in the brain.
    • Mania results from a functional excess.
    • Depletion of monoamines NA and 5HT in the neuronal synapses of the brain cause depression.
    • Drugs that increase the availability of these monoamines are effective in relieving depression.
    • Monoamines and their metabolites are reduced in depressed patients.
    • Interestingly, the direct biochemical effect of antidepressants is rapid but the antidepressant effects can take weeks to develop.

    Antidepressants - Categories

    • Tricyclic antidepressants (TCAs)
    • Monoamine Oxidase Inhibitors (MAOIs)
    • Selective Serotonin Reuptake Inhibitors (SSRIs)
    • Other Antidepressants:
      • Duloxetine (Cymbalta®)
      • Mianserin (Lumin®)
      • Mirtazapine (Avanza®)
      • Moclobemide (Aurorix®)
      • Reboxetine (Edronax®)
      • Venlafaxine (Efexor®)

    Tricyclic Antidepressants

    • Mode of action: Block amine pump (e.g. Chlorpromazine).

    Common Adverse Effects - All Antipsychotics

    • Anticholinergic effects:
      • Blurred vision
      • Dry mouth
      • Constipation
      • Urinary hesitance or retention
    • Sedation
    • Orthostatic hypotension - due to blockade of alpha-receptors, which can lead to syncope and falls
    • Extrapyramidal effects (EPSE)
    • Individual differences in tolerability and occurrence of adverse effects.

    Common Adverse Effects - Anticholinergic Activity

    • All antipsychotics have some degree of anticholinergic activity EXCEPT:
      • Amisulpride
      • Aripiprazole
      • Paliperidone
      • Risperidone
      • Ziprasidone

    Common Adverse Effects - Extrapyramidal Effects (EPSE)

    • Acute dystonia
    • Muscle spasm of the face, neck, tongue, jaw and/or hands.
    • Hyperextension of the neck and trunk, arching of the back.
    • Can interfere with walking, talking, or swallowing.
    • Dystonia’s include:
      • Torticollis
      • Carpopedal spasm
      • Trismus
      • Perioral spasm
      • Oculogyric crisis

    Common Adverse Effects - Drug Induced Parkinsonism

    • Similar to Parkinson’s Disease:
      • Shuffling gait
      • Drooling
      • Tremor
      • Increased rigidity (cogwheel) or Bradykinesia
      • Akinesia has also been reported.
    • Usually develops after weeks to months of treatment.
    • Usually reversible.
    • Treated with anticholinergics or using an alternative medication.

    Common Adverse Effects - Akathisia

    • Motor restlessness
    • Person feels unable to sit/stand still, feels urgent need to move, pace, rock, or tap foot.
    • Can also present as apprehension, irritability and general uneasiness.
    • Often confused with worsening agitation.
    • More common in females.
    • Usually occurs 2-3 days (up to several weeks) after starting treatment and may subside spontaneously.

    Common Adverse Effects - Tardive Dyskinesia

    • Characterised by abnormal movements of the mouth, face, tongue, including:
      • Lip smacking
      • Tongue darting, licking movements
      • Constant chewing movements
      • Sucking
      • Grunting
    • Sometimes abnormal movements of the head, neck, trunk or limbs.
    • May appear after medium to long term treatment.
    • May be irreversible/no cure.

    Common Adverse Effects - Endocrine Effects

    • More common in Women.
    • Due to dopamine receptor blockade - leads to increased prolactin release which may cause:
      • Gynecomastia
      • Galactorrhoea
      • Amenorrhea
      • Anovulation
      • Impaired spermatogenesis
      • Decreased libido
      • Impaired sexual arousal
      • Impotence
      • Anorgasmia

    Common Adverse Effects - Hyperprolactinaemia

    • Dose dependent.
    • Associated with all antipsychotic drugs EXCEPT:
      • Aripiprazole
      • Clozapine
      • Quetiapine
    • Hyperprolactinaemia more likely with:
      • Amisulpride
      • Paliperidone
      • Risperidone
      • Typical antipsychotics

    Common Adverse Effects - Weight Gain

    • Most antipsychotics can cause weight gain.
    • Especially:
      • Clozapine
      • Olanzapine
      • Quetiapine
    • Less in:
      • Amisulpride
      • Aripiprazole
      • Ziprasidone

    Common Adverse Effects - Metabolic Syndrome

    • Schizophrenia and other mental illnesses are an independent risk factor for diabetes.
    • Most antipsychotics increase this risk.
    • Clozapine and Olanzapine are especially associated with:
      • Abnormal glucose tolerance
      • Increased serum lipids

    Infrequent or Rare Adverse Effects - Neuroleptic Malignant Syndrome

    • Rare
    • Coarse tremor
    • Catatonia
    • Potentially fatal
    • Characterised by:
      • Fever (>38oC)
      • Marked muscle rigidity
      • Altered consciousness
      • Autonomic instability (tachycardia, tachypnoea, urinary &faecal incontinence, increased serum creatine kinase concentrations and leucocytosis).

    Infrequent or Rare Adverse Effects - ECG Changes

    • Some antipsychotics can prolong the QTc interval which can lead to life threatening arrhythmias (torsades de pointes), especially:
      • Amisulpride
      • Droperidol
      • Haloperidol
      • Ziprasidone
    • Certain individuals are more susceptible, including:
      • Age/gender (female)
      • Left ventricular failure
      • Recent cardio conversion
      • Electrolyte imbalances (hypomagnesaemia, hypokalaemia, hypocalcaemia)
      • Hepatic dysfunctions

    Pharmacokinetics

    • Most antipsychotic drugs are:
      • Highly lipophilic
      • Highly protein bound
    • Relationship between plasma concentration and effect is highly variable, therefore need to tailor the dose.
    • 40% non-response rate.
    • Some have erratic and unpredictable absorbency.
    • Most antipsychotic drugs enter foetal circulation and breast milk, therefore should be avoided in pregnancy.
    • Neonatal side effects include:
      • Dystonic reactions
      • Sedation
      • Withdrawal.
    • Most have long half lives (t1/2).

    Dosage Forms

    • Tablets
    • Capsules
    • Liquid preparations
    • Depot injections:
      • Fluphenazine (Modecate®)
      • Haloperidol (Haldol®)
      • Fluphenthixol (Fluanxol Depot®)
      • Zuclopenthixol:
        • Zuclopenthixol Acetate (Clopixol Acuphase®)
        • Zuclopenthixol deconoate (Clopixol depot®)
    • Parenteral:
      • Haloperidol
      • Droperidole (Droleptan®)
      • Chlorpromazine (Largactil®)

    Clozapine

    • Used in treatment of patients non-responsive to, or intolerant of other antipsychotics.
    • Able to relieve positive and negative symptoms.
    • Antagonist at D1, D2, D4 and 5HT2 receptors.
    • Can cause profound orthostatic hypotension accompanied by cardiac or respiratory failure.
    • Block the neuronal reuptake of noradrenaline and serotonin into presynaptic terminals.
    • Block other receptors, including:
      • Alpha1 adrenergic
      • Histaminergic
      • Cholinergic
      • Serotonergic

    Tricyclic Antidepressants

    • Indications:
      • Major depression
      • Nocturnal enuresis, urge incontinence
      • Adjunct in pain management
      • ADHD (third line treatment)
      • Migraine prophylaxis
      • Clomipramine also indicated for:
        • Obsessive-compulsive disorder
        • Cataplexy associated with narcolepsy

    Common Adverse Effects - TCAs

    • Anticholinergic effects:
      • Dry mouth
      • Blurred vision
      • Decreased lacrimation
      • Constipation (especially in elderly)
      • Urinary hesitance or retention
      • Decreased GI motility
      • Anticholinergic delirium
      • Confusion
      • Agitation
    • Sedation:
      • Due to H1 block
      • Tolerance develops with time
    • Orthostatic hypotension:
      • Due to α1 block
    • Others
      • Loss of libido and other sexual side effects
      • Tremor
      • Dizziness
      • Anxiety

    Infrequent Adverse Effects - TCAs

    • Cardiovascular effects:
      • Slowed cardiac conduction (especially in high doses)
      • T wave inversion or flattening
      • Arrhythmias
      • Sinus tachycardia
    • Others:
      • Hyperglycaemia
      • Gynecomastia in males
      • Breast enlargement & galactorrhoea in females
      • Manic episodes

    TCA Overdose

    • Cardiovascular toxicity:
      • Leading cause of death in overdose
      • Death has occurred in children with low doses
    • TCAs have a direct cardiac depressing action similar to class 1 antiarrhythmics.
    • Cardiac toxicity and hypotension are difficult to manage.
    • ECG:
      • QRS complex is prolonged.
      • QT interval is prolonged due to prolongation of the QRS complex.

    Withdrawal Syndrome

    • TCAs must be withdrawn slowly to avoid discontinuation syndrome.
    • May develop cholinergic rebound:
      • Runny nose
      • Hypersalivation
      • Diarrhea
      • Abdominal cramping
      • Sleep disturbances

    Monoamine Oxidase Inhibitors (MAOIs)

    • Include:
      • Phenelzine (Nardil®)
      • Tranylcypromine (Parnate®)
    • Mode of action:
      • Bind irreversibly to monoamine oxidase (enzyme), responsible for the breakdown of the biogenic amine neurotransmitters:
        • Noradrenaline
        • Dopamine
        • Serotonin

    Monoamine Oxidase Inhibitors (MAOIs)

    • Indications:
      • Major depression (2nd line)
      • Some anxiety disorders (including phobic and panic disorders (2nd line)
    • Common Adverse Effects:
      • Orthostatic hypotension
      • Weight gain
      • Sleep disturbances (especially insomnia – not given after 3pm)
      • Agitation
      • Impotence
    • Rare:
      • Hypertensive Crisis

    Monoamine Oxidase Inhibitors (MAOIs)

    • Most important side effect is HYPERTENSIVE CRISIS (which may result in death).
    • A sudden paroxysmal rise in blood pressure may occur.
    • It is usually associated with foods containing tyramine (or some drug interactions).
    • The metabolism of some amine drugs, e.g., ---

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    Description

    This quiz covers critical information regarding Clozapine, including its side effects and precautions. Additionally, it explores the role of anticholinergic drugs in managing different conditions and their application in psychiatric treatment. Understanding these concepts is essential for healthcare professionals.

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