Psychopharmacology Flashcards
What are TCA’s?
Tricyclic antidepressants
What affects do TCA’s have on the heart?
Causes QT lengthening
How do tertiary TCA’s produce side effects?
Side chains are present and cross react with other types of receptors which cause:
antihistaminic (sedation and weight gain)
anticholinergic (dry mouth and eyes, memory deficits, constipation)
antiadrenergic (orthostatic hypotension, sedation, sexual dysfunction) effects
What receptors do Tertiary TCAs mainly act upon?
Serotonin receptors
What do secondary TCA’s act upon?
They block noradrenaline and have less severe side effects
How do MAOIs work?
Bind irreversibly to MAO and prevent inactivation of norepinephrine, dopamine and serotonin which leads to increased synaptic levels
What are the side effects of MAOI’s?
Orthostatic hypotension, weight gain, dry mouth, sedation, sexual dysfunction and sleep disturbance
What are SSRI’s?
Selective serotonin reuptake inhibitors
- block the presynaptic serotonin reuptake
What do SSRI’s treat?
Anxiety and depression
What are the side effects of SSRI’s?
GI upset, sexual dysfunction, anxiety, restlessness, nervousness, insomnia, fatigue, sedation or dizziness
What are the pros and cons of paroxetine?
Pros
- short half life
- Sedating properties if dosed at night offers good initial relief from anxiety and insomnia
Cons
- Significanant CYP2D6 inhibition
- Sedation, weight gain
- likely to cause a discontinuation syndrome
What are the pros and cons of sertraline?
Pros
- Weak p450 interactions
- Short half life with lower build up of metabolites
- Less sedating when compared to paroxetine
Cons
- max absorption requires a full stomach
- Increased no. of GI adverse drug reactions
What are the pros and cons of fluoxetine?
Pro’s
- Long half life which limits discontinuation syndrome developing
- May provide increased energy initially
Cons
- Long half life so active metabolites may build up
- Significant P450 interactions so not good choice on someone on lots of meds
- Initial activation may increase anxiety and insomnia
- More likely to induce mania
What are the pros and cons of citalopram?
Pro
- low inhibition of p450 so fewer drug-drug interactions
- intermediate half life
Cons
- QT interval prolongation with doses 10-30 mg
- Sedating
- GI side effects
Pros and cons of esciltalopram?
Pro
- low overall inhibtion of p450
- Intermediate half life
- effective in acute response and remission
cons
- QT level prolongation
- nausea, headache
Fluvocamine pros and cons
Pro
- Shortest half life
- Analgesic properties
Cons
- GI distress, headaches, sedation, weakness
What do SNRI’s do?
Inhibit serotonin and noradrenergic reuptake like TCAs without antihistamine, antiandrinergic or anticholinergic side effects
Velaflaxine pros and cons?
Minimal drug interactions and almost p450 activity
Short half life
Cons
- Can cause increase in diastolic BP
- Nausea
- Discontinuation syndrome
- QT prolongation
- Sexual side effects
Mirtazapine pros and cons
Pro
- Can be used as a hypnotic at lower doses
Con
- Increase in serum cholesterol
- Weight gain
- Sedating
Buproprion pros and cons?
Pro
- No weight gain, sexual side effects, sedation, cardiac interations
- Low induction of mania
- Second line ADHD agent
Cons
- Increases seizure risk
- Can cause anxiety, agitation and insomnia
- Can induce psychotic symptoms at high doses
When are mood stabilisers indicated?
Bipolar disorder, cyclothymia, schizoaffective disorder
What are the classes of mood stabilisers?
Lithium, anticonvulsants or antipsychotics
What are the pros and cons of lithium?
Pro
- Reduces suicide rate
- Long term prophylaxis of mania and depressive episodes
Cons
- Many side effects including GI distress, thyroid abnormalities, Hair loss, acne, slows cognition, intention tremor etc
- can cause lithium toxicity
Describe mild lithium toxicity?
levels 1.5-2.0
Causes vomiting, diarrhea, ataxia, dizziness, slurred speech, nystagmus.
Describe moderate lithium toxicity?
levels 2.0-2.5
Causes nausea, vomiting, anorexia, blurred vision, clonic limb movements, convulsions, delirium, syncope
Describe severe lithium toxicity?
levels >2.5
Causes generalized convulsions, oliguria and renal failure
Pros and cons of Valproic Acid?
Pro
Effective in mania prophylaxis
Well tolerated
Con
Not effective in depression prophylaxis
Disrupts platelets
Causes nausea, vomiting, weight gain, sedation and tremor
Carbamazepine pros and cons
Pro
- Can be used as first line treatment for acute mania and mania prophylaxis
- Good for rapid cyclers
Cons
- Rash, nausea, sedation, vomiting, ataxia, confusion, water retention
- many drug-drug interactions
What key pathways in the brain are affected by dopamine?
Mesocortical
Mesolimbic
Nigrostriatal
Tuberoinfundibular
Name some atypical antipscyhotics
Rispiridone, clozapine, olanzapine
What is discontinuation syndrome?
Discontinuation of a drug abruptly
Can cause different symptoms in different drug classes.
SSRIs cause nausea, headache, dizziness, chills, paraesthesia, insomnia, “electric shock” feelings in the head.
TCAs cause anxiety, insomnia, headache, motor disturbance, malaise
What is serotonin syndrome ?
Influx of too much serotonin in the CNS = overstimulation of 5HT2A receptors resulting in
Cognitive Side Effects (headache, agitation, confusion, hallucinations, coma)
Autonomic Side Effects (shivering, sweating, vasoconstriction, nausea, tachycardia, diarrhoea)
Somatic Side Effect (myoclonus, hyperreflexia, tremor)
What receptors in the brain do Atypical Antipsychotics block?
Dopamine receptors
What are the side effects of atypical antipsychotics?
Decreased libido, abnormal menstruation, inability to ejaculate, infertility. hyperprolactinaemia, seizures, gynaecomastia, weight gain
What are the side effects of typical antipsychotics?
Dry mouth, muscle stiffness, muscle cramps, tremors, weight gain and EPS
What are EPS?
Extrapyramidal Side Effects:
Akathisia
Parkinsonism
Dystonia
Name some typical antipsychotics
Haloperidol
Loxapine
Beriperidol
What drugs can be used to treat dementia?
Cholinesterase Inhibitors
NMDA inhibitors
Antidepressants, Antipsychotics (can be used to treat the co-morbid symptoms)
What is the effect of cholinesterase inhibitors on Alzheimers?
Prevent acetylcholinesterase from breaking down acetylcholine in the brain leading to an increased concentration of acetylcholine resulting in better communication between nerves in the brain
Name some cholinesterase inhibitors?
Rivastigmine and Galantamine
What is the effect of NMDA antagonists in Alzheimers?
blocks nerve cells within the brain from the effects of excess glutamate, thus preventing further damage
Name an NMDA antagonist?
Memantine
What are the effects of benzodiazepines?
Benzodiazepines enhance GABA and thus result in hypnotic, sedative and anxiolytic effects
What are the side effects of benzodiazepines?
Drowsiness, dizziness, diminished alertness, decrease in concentration span, lack of coordination, decreased libido
What are the long term effects of benzodiazepines?
Cognitive impairment
Tolerance and dependence
What happens after sudden withdrawal of benzodiazepines?
Insomnia, tremors, GI upset, agitation, muscle spasm
Name some benzodiazepines
Clonazepam, lorazepam, diazepam, zopiclone
