Psychopharmacology Flashcards
What are indications for antisepressants?
- unipolar + bipolar depression
- organic mood disorders
- schizoaffective disorder
- anxiety disorders
Typically, how long is the delay between the start of antidepressant treatment and symptom improvement?
3-6 weeks
What should be done if there is no symptomatic improvement after 2 months on antidepressants?
- switch antidepressant
- or augment with another agent
What are the different classifications of antidepressants?
- tricyclic antidepressants (TCAs)
- monoamine oxidase inhibitors (MAOIs)
- selective serotonin reuptake inhibitors (SSRIs)
- serotonin/noradrenalin reuptake inhibitors (SNRIs)
- novel antidepressants
What are the charaterisitics of trycyclic antidepressants (TCAs)?
- very affective
- many side effects
- antihistaminic (sedation, weight gain)
- anticholinergic (dry mouth/eyes, constipation, memory defects, delirium)
- antiadrenergic (orthostatic hypotension, sedation, sexual dysfunction)
- lethal in overdose
- can cause QT lengthening
How do tertiary TCAs work and what are some example drugs?
- act mainly on serotonin receptors
- tertiary amine side chain, cross react, cause side effects
- imipramine
- amitriptyline
- doxepin
- clomipramine
How do secondary TCAs work and what are some example drugs?
- mainly block noradrenaline receptors
- side effects less severe
- desipramine
- notrtripptyline
How do monoamine oxidase inhibitors (MAOIs) work?
- bind irreversibly to monoamine oxidase, prevents inactivation of; norepinephrine, dopamine, serotonin
- very effective for depression
What are the side effects of monoamine oxidase inhibitors (MAOIs)?
- orthostatic hypotension
- weight gain
- dry mouth
- sedation
- sexual dysfunction
- sleep disturbance
- hypertensive crisis- if taken with tyramine-rich foods (cheese, red wine, processed meat, beans)
- serotonin syndrome- if taken with med inc. serotonin or sympathmimetic actions
What are the symptoms and complications of serotonin syndrome?
- abdominal pain, diarrhoea, sweats
- tachycardia
- HTN
- myoclonus
- irritability, delirium
- hyperpyrexia
- cardiovascular shock
- death
* must wait 2 weeks when switching from SSRIs to MAOIs
How do selective serotonin reuptake inhibitors (SSRIs) work, what are their side effects and what are some example drugs?
- block presynaptic serotonin reuptake
- treat anxiety + depression
- little risk of overdose
- GI upset
- sexual dysfunction
- SSRI activation syndrome
- SSRI discontinuation syndrome
- setraline
- citalopram
- fluoxetine (prozac)
What is activation syndrome and discontinuation syndrome?
Activation syndrome:
- nausea, anxious, restlessness, suicidal tendencies
- a few days
Discontinuation syndrome:
- nausea, anxious, agitation, disequilibrium, dysphoria
- not a craving
- inc. risk if short half-life
How do serotonin/norepinephrine reuptake inhibitors work and what are some example drugs?
- inhibit serotonin + norepinephrine reuptake
- without the effects of TCAs
- for depression, anxiety, neuropathic pain
- duloxetine
- mirtazapine
- buproprion
What are the options following resistance to treatment of antidepressants?
- combination of antidepressants
- adjunctive treatment with lithium
- adjunctive treatment with atypical antipsychotic
- ECT
What are the different classes of mood stabilisers and what are the indications for their use?
- lithium
- anticonvulsants
- antipsychotics
- bipolar
- cyclothymia
- schizoaffective
What are the benefits of lithium?
- only medication to dec. suicide rates
- effective prophylaxis of mania + depressive episodes in BAD
- good response if:
- prior long-term response
- family member had good response
- classic pure mania
- mania followed by depression
What must be done when prescribing lithium?
- baseline U + Es
- baseline TSH
- pregnancy test (risk of Ebstein’s anomaly)
- monitor at 5 days, 3 months, 6 months
- goal blood level- 0.6-1.2
What are common side effects of lithium?
- GI distresses
- thyroid abnormalities
- nonsignificant leukocytosis
- polyuria/polydipsia
- ADH antagonism
- interstitial renal fibrosis (in few)
- hair loss, acne
- dec. seizure threshold, cognitive slowing, intention tremor
What can occur as a result of lithium toxicity?
- mild (1.5-2.0)- vomiting, diarrhoea, ataxia, dizziness, slurred speech, nystagmus
- moderate (2.0-2.5)- N + V, anorexia, blurred vision, clonic limb movements, convulsions, delirium, syncope
- severe (> 2.5)- generalised convulsions, oliguria, renal failure
What are the benefits of valproic acid (anticonvulsant) and what must be done when prescribing it?
- effective in mania prophylaxis (not depression)
- better tolerated than lithium
- FBC
- LFTs
- pregnancy test
- start folic acid supplement (women)
- monitor after 4/5 days
- goal blood level- 50-125
What are the side effects of valproic acid (anticonvulsant)?
- thrombocytopenia, platelet dysfunction
- N + V, weight gain
- sedation, tremor
- hair loss
- inc. risk neural tube defect
What are the indications for carbamazepine (anticonvulsant) and what must bbe done when prescribing it?
- acute mania, mania prophylaxis
- rapid cyclers, mixed patients
- FBC
- LFTs
- ECG
- monitor after 5 days, 1 month (adjust doses due to own metabolism)
- goal blood level- 4-12mcg/ml
What are the side effects of carbamazepine (anticonvulsant)?
- rash (most common)
- N + V, diarrhoea
- sedation, diziness, ataxia, confusion
- AV conduction delays
- aplastic anaemia + agranulocytosis
- water retention -> hyponatraemia
- drug-drug interactions
What are the side effects of lamotrigine (anticonvulsant)?
- N + V
- sedation, diziness, ataxia, confusion
- toxic epidermal necrolysis, Steven Johnson’s syndrome
* any rash, must stop medication
What are the indications for antipsychotics?
- schizophrenia
- schizoaffective disorder
- bipolar disorder (mood stabilisation)
- psychotic depression
- resistant anxiety disorders (augmenting agent)
How can the mesocortical pathway cause psychosis?
- where negative symptoms + cognitive disorders arise
- too little dopamine in the mesocortical pathway = psychosis
How can the mesolimbic pathway cause psychosis?
- where positive symptoms arise
- too much dopamine in mesolimbic pathway = psychosis
How do typical antipsychotics work?
- D2 dopamine receptor antagonists
- high potency typicals bind to bind to D2 receptors with high affinity
What are the side effects of typical antipsychotics?
High potency:
- extrapyramidal side effects
- fluphenazine, haloperidol, pimozide
Low potency: (can interact with nondopaminergic receptors)
- cardiotoxic
- anticholinergic side effects
- chlorpromazine, thioridazine
How do atypical antipsychotics work?
- serotonin-dopamine 2 antagonist (SDAs)
- affect dopamine + serotonin
- in the 4 key dopamine pathways of the brain
- resperidone
- olanzapine
- quetiapine
- aripiprazole
- clozapine
What are adverse effects of antipsychotics?
- tardive dyskinesia (TD)
- involuntary muscle movement
- may not resolve with drug removal
- neuroleptic malignant syndrome (NMS)
- severe muscle rigidity
- fever
- altered mental status
- autonomic instability
- elevated WBC, CPKm LFTs
- potentially fatal
- extrapyramidal side effects (EPS)
- acute dystonia
- Parkinson syndrome
- akathisia
What drug are agents for extrapyramidal side effects (EPS)?
- anticholinergics
- benztropine
- dopamine facilitators
- amantadine
- b-blockers
- propanolol
What are indications for anxiolytics?
- panic disorder
- generalised anxiety disorder
- substance-related disorders
- buspirone
- benzodiazapines
