Psychopharmacy Flashcards
For what conditions are antidepressants suitable?
- unipolar and bipolar depression
- organic mood disorders
- schizoaffective disorder
- anxiety disorders including OCD
- panic
- social phobia
- PTSD
- impulsivity associated with personality disorders
- premenstrual dysphoric disorder
How long does it normally take for antidepressant drugs to become effective?
2-4 weeks
When would you consider switching an antidepressant drug or adding another?
if there is no improvement after a trial of about 2 months and of adequate dose
What advice is there regarding prophylaxis using antidepressants?
- after the first episode continue the drugs for 6months to a year
- second episode continue for 2 years
- third episode discuss life long
What are the 5 main classifications of antidepressant?
- tricyclic antidepressants
- MAOIs
- Selective Serotonin Reuptake Inhibitors (SSRIs)
- Serotonin/Noradrenaline Reuptake Inhibitors (SNRIs)
- Novel antidepressants
What are examples of tertiary tricyclic antidepressants?
- clomipramine
- amitriptyline
Who are tricyclic antidepressants unsuitable for and why?
- have strong anticholinergic properties and are thus unsuitable for the elderly and for patients with benign prostatic hypertrophy, glaucoma, or chronic constipation. All heterocyclics, particularly maprotiline and clomipramine, lower the threshold for seizures.
- lots of side effects!
When would MAOIs be considered for use?
or treating refractory or atypical depression when SSRIs, tricyclic antidepressants, and sometimes even electroconvulsive therapy are ineffective.
What are side effects of MAOIs?
- orthostatic hypotension
- weight gain
- dry mouth
- sedation
- sexual dysfunction
- sleep disturbance
What is meant by the ‘cheese reaction’?
hypertensive crisis can develop when MAOIs are taken with tyramine rich foods or sympathomimetics i.e. must restrict diet by excluding cheese and wine
What is serotonin syndrome?
complication that can occur if MAOIs are taken with other medications that increase serotonin
What are symptoms of serotonin syndrome?
- abdominal pain
- diarrhoea
- sweats
- tachycardia
- hypertension
- myoclonus
- irritability
- delirium
- can lead to hyperpyrexia, cardiovascular shock and death
How can serotonin syndrome be avoided?
- need to wait 2 weeks before switching from an SSRI to an MAOI
- exception is fluoxetine where need to wait 5 weeks because of long half-life
What are SSRIs?
- selective serotonin reuptake inhibitors
- can treat both anxiety and depression
- very safe! Not likely to cause harm if lots taken
What is discontinuation syndrome?
agitation, nausea, disequilibrium and dysphoria arising from coming off SSRIs
What is activation syndrome?
- issue with SSRIs
- increase in serotonin can transiently make the patient more agitated and can last 2-10 days
What can you consider to avoid discontinuation syndrome?
consider switching to fluoxetine as longer half life so may be less profound effect coming off them
What are examples of SSRIs?
- paroxetine
- sertraline
- fluoxetine (prozac)
- citalopram
- escitalopram
- fluvoxamine
What are some side effects of using SSRIs?
- activation syndrome
- discontinuation syndrome
- increased agitation
- sexual dysfunction
- some anticholinergic effects such as dry mouth and some cardiac conduction effects
What do SNRIs do?
inhibit both serotonin and noradrenergic reuptake like the TCAs, but with less side effects
What are SNRIs useful for treating?
- depression
- anxiety
- neuropathic pain
What are examples of SNRIs?
- venlafaxine
- duloxetine
What are common problems associated with SNRI use?
- nausea in first 2 weeks
- may cause increase in blood pressure at high doses (venlafaxine)
What are 2 examples of a novel antidepressant?
- mirtazepine - good augmenting agent
- buproprion-good augmenting agent
What are common problems associated with mirtazepine?
- increase serum cholesterol
- sedating at low doses
- activating at high doses
- associated with weight gain
What are common problems associated with bupropion?
- may increase seizure risk in high doses (avoid in patients with traumatic brain injury, bulimia and anorexia)
- may cause anxiety
- abuse potential
What can be done to combat treatment resistance? (4 options)
- combination of antidepressants e.g. SSRI or SNRI with Mirtazepine
- adjunctive treatment with lithium
- adjunctive treatment with atypical antipsychotic e.g. olanzapine
- ECT!
When are mood stabilisers indicated?
- bipolar
- cyclothymia
- schizoaffective disorder
What are the 3 classes of mood stabilisers?
- lithium
- anticonvulsants
- antipsychotics
When is lithium effective?
-effective in long term prophylaxis of both mania and depressive episodes
What are factors predicting good response to lithium?
- prior long term response or family member with good response
- classic pure mania
- mania is followed by depression
What must you obtain before starting lithium?
- TSH levels and US and Es
- pregnancy test
What monitoring is required taking lithium?
- steady state is achieved after 5 days (check 12 hours after last dose)
- once stage check levels every 3 months
- check TSH and creatinine every 6 months
What are the goal blood levels of lithium?
between 0.6 and 1.2
What are side effects of using lithium?
- Most common are GI distress including reduced appetite, nausea/vomiting, diarrhea
- Thyroid abnormalities
- Nonsignificant leukocytosis
- Polyuria/polydypsia secondary to ADH antagonism. In a small number of patients can cause interstitial renal fibrosis.
- Hair loss, acne
- Reduces seizure threshold, cognitive slowing, intention tremor
- lithium toxicity
What constitutes mild lithium toxicity? What are symptoms of it?
- levels 1.5-2.0
- vomiting
- diarrhoea
- ataxia
- dizziness
- slurred speech
- nystagmus
What constitutes moderate lithium toxicity? What are symptoms of it?
- levels 2.0-2.5
- nausea
- vomiting
- anorexia
- blurred vision
- clonic limb movements
- convulsions
- delirium
- syncope
What constitutes severe lithium toxicity? What are symptoms of it?
- levels >2.5
- generalised convulsions
- oliguria
- renal failure
What are 3 examples of anticonvulsants that can be used as mood stabilisers?
- valproic acid
- lamotrigine
- carbamazepine
What are factors that will predict a good response to valproic acid?
- rapid cycling patients
- comorbid substance misuse
- mixed patients
- patients with comorbid anxiety disorders
What tests are required before prescribing valproic acid?
- baseline LFTs
- pregnancy test
- FBC
How is use of valproic acid monitored?
- steady state achieved after 4-5 days (check 12 hours after last dose)
- repeat FBC and LFTs
What are side effects of valproic acid?
- Thrombocytopenia and platelet dysfunction
- Nausea, vomiting, weight gain
- Sedation, tremor
- Increased risk of neural tube defect 1-2% vs 0.14-0.2% in general population secondary to reduction in folic acid
- Hair loss
When is carbamazepine used in treatment of mood disorders?
- first line agent for acute mania and mania prophylaxis
- indicated for rapid cyclers and mixed patients
What tests are required before starting carbamazepine?
- LFTs
- FBC
- ECG
How is use of carbamazepine monitored?
- steady state achieved after 5 days (check 12 hours after last dose)
- repeat FBC and LFTs
- need to check level and adjust dosing around 1 month because induces own metabolism
What are side effects of carbamazepine?
- Rash- most common SE seen
- Nausea, vomiting, diarrhea
- Sedation, dizziness, ataxia, confusion
- AV conduction delays
- Aplastic anemia and agranulocytosis (<0.002%)
- Water retention due to vasopressin-like effect which can result in hyponatremia
- Drug-drug interactions!
In addition to the indications of the other anticonvulsants in treatment of mood disorders, what is lamotrigine additionally beneficial for?
neuropathic/ chronic pain
What baseline tests are required before starting lamotrigine?
LFTs
How should lamotrigine be initiated?
- start 25mg daily for 2 weeks then double every 2 weeks up to 100mg
- beware that of patient stops meds for 5 days or more then have to start titration of meds from start again!
What are some side effects of lamotrigine?
- Nausea/vomiting
- Sedation, dizziness, ataxia and confusion
- The most severe are toxic epidermal necrolysis and Stevens Johnson’s Syndrome. The character/severity of the rash is not a good predictor of severity of reaction. Therefore, if ANY rash develops, discontinue use immediately.
- Blood dyscrasias have been seen in rare cases.
- Drugs that increase lamotrigine levels: VPA (doubles concentration, so use slower dose titration), sertraline.
What conditions are antipsychotics indicated for use?
- schizophrenia
- schizoaffective disorder
- bipolar disorder- for mood stabilization and/or when psychotic features are present
- psychotic depression
- augmenting agent in treatment resistant anxiety disorders.
What tends to be considered the problem is schizo disorders?
too much or too little dopamine
What are ‘typical’ antipsychotics?
those that affect D2 dopamine receptors
What is wrong with typical antipsychotics?
- have higher risks of extrapyramidal effects
- may be sedating
- may be cardiotoxic
- may have anticholinergic effects e.g. hypotension etc
What are 3 examples of typical antipsychotics?
- fluphenazine
- haloperidol
- pimozide
What are ‘atypical’ antipsychotics?
- newer types
- are serotonin- dopamine 2 antagonists
What are examples of atypical antipsychotics?
- risperidone
- olanzapine
- quetiapine
- aripiprazole
- clozapine
What are risks of using atypical antipsychotics?
- weight gain
- hyperprolactinaemia
- some cause hyperglycaemia (olanzapine) diabetes!!
- hypercholerterolaemia (quetiapine)
- sedation (clozapine ++)
- abnormal LFTs
Antipsychotic not associated with weight gain.
aripiprazole
What might you consider as prophylaxis using antipsychotics?
long acting intramuscular medications
What are 3 common adverse effects using antipsychotics?
- tardive dyskinesia
- neuroleptic malignant syndrome
- extrapyramidal side effects
What is tardive dyskinesia?
involuntary muscle movements that may not resolve with drug discontinuation
What is neuroleptic malignant syndrome?
- rare, life-threatening syndrome caused by taking some antipsychotics
- characterised by severe muscle rigidity, fever, altered mental status, autonomic instability, elevated WBC, CPK and LFTs
Extrapyramidal side effects
acute dyskinesias and dystonic reactions, tardive dyskinesia, Parkinsonism, akinesia, akathisia, and neuroleptic malignant syndrome.
What can be used to treat extrapyramidal side effects associated with antipsychotic use?
- anticholinergics e.g. benztropine
- dopamine facilitators such as amantadine
- beta blockers
What are benzodiazepines used to treat?
- insomnia
- parasomnias
- anxiety disorders
- alcohol withdrawal
What are side effects/ cons of using benzodiazepines?
- Somnolence
- Cognitive deficits
- Amnesia
- Disinhibition
- Tolerance
- Dependence
