Pre-Midterm Flashcards
Zuclopenthixol
- moderate potency
- Blocks D1 and D2 receptors
- Has three main forms:
1. Zuclopenthixol dihydrochloride - used for patients who are compliant with oral men’s
2. Zuclopenthixol acetate - used in a true sedation of psychotic patients (2-3 days sedation)
3. Zuclopenthixol decanoate - long acting IM injection for poor compliant patients (weekly) - Has only dopamine related side effects: Extrapyramidal symptoms, hyperprolactinemia, anti0emetic, tardive dyskinesia
Typical
Haloperidol
High potency
Blocks D1 and D2 dopamine receptors
Only dopamine related side effects:
- extrapyramidal symptoms, hyperprolactinemia, anti-emetic, tardive dyskinesia
Typical
Chlorpromazine
- DA antagonist: affect extrapyramidal system, pituitary, chemoreceptor trigger zone, can illicit tardive dyskinesia
- Weak alpha-adrenergic antagonist (postural hypotension)
- Muscarinic antagonist (constipation, sedation, hypotension, anxiolytic)
- Histamine antagonist (sedation, itching, etc.)
In some countries, such as the United States, injections of antipsychotics such as haloperidol can be ordered by a court at the request of a psychiatrist
Typical
Atypical
Substantially lower risk of extrapyramidal side effects
Positive Symptoms
Symptoms that most individuals do not normally experience but are present in the disorder. It reflects an excess or distortion of normal functions (i.e., experiences and behaviours that have been added to a person’s normal way of functioning
Example: Hallucinations, Delusions, Bizarre behaviour
Negative Symptoms
symptoms that are not present or that have diminished in the affected persons but are normally found in healthy people. It reflects a diminution or loss of normal functions (i.e., something that has been taken away from a person’s normal way of functioning)
Example: Poverty of Speech, social inattentiveness
Clozapine (Clozaril)
- D1, D2, and 5-HT (Serotonin) antagonist
- effective on both positive and negative symptoms
- little or on extrapyramidal symptoms but weight gain
- BUT bone marrow suppression produces agranulocytosis and death
- Mandatory weekly blood testing
Atypical
Risperidone (Risperdal)
- D2 and serotonin antagonist
- at optimal doses, reduces positive and negative symptoms with little or no EPS or other side effects
First line atypical antipsychotic
Olanzapine (Zyprexa)
- D2 and serotonin antagonist
- reduces positive and negative symptoms with little or no side effects (other than weight gain, dizziness, and dry mouth)
- Seems to halt progression of schizophrenia
First line atypical antipsychotic
Quetiapine (Seroquel)
- D1, D2, and serotonin antagonist
- actions similar to risperidone and olanzapine but cheaper
First line atypical antipsychotic
Tardive Dyskinesia
- Repetitive painless, involuntary, tic-like movements of face, eyelids, mouth, tongue, extremities, or trunk
- frequently appears after long-term or high-dose is of antipsychotic drugs
Neuroleptic Malignant Syndrome (NMS)
- Due to massive DA black; increase incidence with high potency and depot neuroleptic
- Fever, muscle rigidity, unstable blood pressure, lactic acidosis, shock and dehydration
Treatment: stop drug, hydrate, cool, Dantrolene (inhibits calcium release in muscles which inhibits contraction), bromocriptine (dopamine agonist) (5% mortality)
Neurosis
- A class of functional mental disorders involving distress with neither delusions nor hallucinations, whereby behaviour is not outside socially acceptable norms
- maladaptive learned behaviour
Psychosis
- Psychosis is given to the more severe forms of psychiatric disorders, during which hallucinations, delusions and impaired insight may occur:
1. Loss of contact with reality (lack of reality testing)
2. Disruption of brain function
3. Neurochemical imbalance induced by: drugs/chemicals, neurodegeneration, genetic abnormality
Alzheimer’s Disease
- A neurodegenerative disease of the elderly
- 1/12 of the population 65-75 years of age
- 1/3 of the population >85 years of age
- Accounts for 60-80% of all dementias
Dementia
- Short term memory loss
- Impaired memory retrieval
- impaired ability to generate ideas and to manipulate concepts mentally
- impaired judgement and evaluation
- Labile and inappropriate emotions
- Motor functions are generally intact until late stages of the disease
Donepezil
- Reversible AChE inhibitor
- Indicated for mild-moderate AD
- Half-life of 70 hours
- Dosing must be titrated over weeks to months
- 100% oral bioavailability and crosses the BBB easily with 40% plasma protein binding
Galantamine
- Reversible AChE inhibitor
- Indicated for mild-moderate vascular and Alzheimer’s type dementia
- Half-life of 7 hours
- Dosing must be titrated over several weeks
- 80-100% oral bioavailability and crosses BBB easily with 18% plasma protein binding
- Sleep aid (enhances dreaming), memory enhancer
Rivastigmine
- Butyrylcholinesterase and AChE inhibitor
- Indicated for mild-moderate Alzheimer’s type and Parkinson’s related dementia
- Half-life of 1.5 hours
- Dosing must be titrated over several weeks
- 40% oral bioavailability and crosses BBB easily with 40% plasma protein binding
- Bypasses cytochrome P450 pathways for reduced drug-drug interactions (reduced adverse effects)
Tranylcypromine
- Half life: 2 hours but binds irreversibly to MAO, so 1 dose lasts about 7 days
- Inhibits both MAO-A and MAO-B, this increases the levels of 5-HT, NE, and DA in neurons in the brain
- increases the absorption of dietary tyramine from the gut into the blood stream
MAO inhibitor
Moclobemide
- Half-life: 2 hours but binds reversible, competitive binding
- is a selective inhibitor of MAO-A: increases levels of serotonin and noradrenaline in brain without affecting blood tyramine
- the ‘wine-cheese’ reaction is usually not a problem because moclobemide has a short half-life, is taken after meals, is reversible, and does not alter MAO-B in the liver
Anti-depressant
Imipramine and Amitriptyline
Imipramine: half life 17 hours
Amitriptyline: half life 38 hours
- Inhibit both noradrenaline and serotonin reuptake
- broad spectrum
- also block muscarinic and alpha one adrenergic receptors producing impaired memory, etc., and postural hypotension, respectively.
NSRIs
Antidepressant
Fluoxetine
- Half life of 3 days
- has active metabolite norfluoxetine, total biological half-life about seven days
- lacks affinity for neurotransmitter receptors
- inhibits cytochrome P450 2D6 (and others) causing potentially fatal drug interactions with narcotics, beta blockers, etc.
- inhibits only serotonin reuptake
SSRI
Antidepressant
Fluvoxamine and Paroxetine
Fluvoxamine: Half-life of 15 hours Paroxetine: Half-life of 24 hours - Inhibit Serotonin reuptake - lack active metabolites - Have less serious P450 related drug interactions than fluoxetine SSRIs Antidepressant
Sertraline and Citalopram
Sertraline: Half-life of 26 hours Citalopram: Half-life 35 hours - Inhibitors of serotonin SSRIs Antidepressants
Desipramine
- Half-life: 38 hours
- is the active metabolite of imipramine
- has less affinity for muscarinic and alpha one receptors than imipramine
- selective noradrenaline reuptake inhibitor
SNERI
Antidepressant
Nortripyline
- Half-life: 55 hours
- is the active metabolite of Amitriptyline
- has less affinity for muscarinic and alpha one receptors than Amitriptyline
- selective noradrenaline reuptake inhibitor
Antidepressant
SNERI
