Psychopharmacology - Part 2 Flashcards
What are the indications for mood stabilizers?
Bipolar, cyclothymia and schizoaffective disorder
What are the classes of mood stabilizers?
Lithium
Anticonvulsants
Antipsychotics
Describe lithium
Only medication to reduce suicide rate
Effective long term prophylaxis of both mania and depressive episodes
Positive factors - FH with good response, classic pure mania and mania following depression
What is checked before starting lithium?
Get baseline U+Es and TSH
Check pregnancy - first trimester is associated with Ebstein’s anomaly
What is the monitoring on lithium?
Steady state achieved after 5 days
Once stable check 3 months and TSH + creatinine 6 months
Goal is 0.6-1.2
What are the lithium side effects?
GI distress - reduced appetite, N/V and diarrhoea
Thyroid abnormalities
Polyuria/ polydipsia secondary to ADH antagonism
Hair loss and acne
Reduced seizure threshold, cognitive slowing and intention tremor
What are mild levels of lithium toxicity?
1.5 - 2
Vomiting, diarrhoea, ataxia, dizziness, slurred speech and nystagmus
What is moderate lithium toxicity?
2-2.5
N/V, anorexia, blurred vision, clonic limb movements, convulsant, delirium and syncope
What is severe lithium toxicity?
> 2.5
Generalised convulsions, oliguria and renal failure
Describe valproic acid (Depakote) - anticonvulsant
Effective as lithium in mania prophylaxis but not in depression
Positive response - rapid cycling patients, comorbid substance issues, mixed patients and comorbid anxiety disorders
Better tolerated than lithium
What is checked in valproic acid?
LFTS, pregnancy test and FBC
Avoid in women of child bearing age - neural tube defects
Goal is between 50-125
What are side effects of valproic acid?
Thrombocytopenia and platelet dysfunction
N/V, weight gain, sedation, tremor and hair loss
When is carbamazepine (Tegretol) used - anticonvulsant?
First line agent for acute mania and mania prophylaxis
Indicated for rapid cycles and mixed patients
What is checked before going on carbamazepine?
Baseline LFTS, FBC and ECG
Target is 4-12mcg/ml
Need to check level and adjust dosing after a month because induces own metabolism
What are the side effects f carbamazepine?
Rash, N/V, diarrhoea, sedation, dizziness, ataxia, confusion, AV conduction delays, aplastic anaemia, agranulocytosis and water retention
Drug - drug interaction
Describe lamotrigine (Lamictal) - anticonvulsant
Also use for neuropathic/ chronic pain
Baseline LFTS before starting
Start on 25mg for 2 weeks then 50mg for 2 weeks when 100mg (rash if too fast) and if stopped then have to start again
What are the side effects of lamotrigine?
N/V, sedation, dizziness, ataxia and confusion
Severe - toxic epidermal necrolysis and SJS
Blood dyscrasias
Drug interactions - VPA and sertraline
What are the indications for antipsychotics?
Schizophrenia, schizoaffective disorder, bipolar for mood stabilization or psychotic features and psychotic depression
Describe typical antipsychotics
D2 dopamine receptor antagonists
High potency bind to D2 receptor in high affinity - higher risk of extrapyramidal side effects
Fluphenazine, Haloperidol and Pimozide
Describe low potency typical antipsychotics
Have less affinity for the D2 receptors but tend to interact with non-dopaminergic receptors - more cardiotoxic and anticholinergic effects (sedation and hypotension)
Chlorpromazine and Thioridazine
What are the adverse effects of antipsychotics?
Tardive dyskinesia - involuntary muscle movements that may not resolve
Neuroleptic malignant syndrome
Extrapyramidal side effects - Acute dystonia and Parkinson’s
Akathisia
What are the symptoms in neuroleptic malignant syndrome?
Severe muscle rigidity, fever, altered mental status, autonomic instability, elevated WBC and CPK
What are agents for extrapyramidal symptoms?
Anticholinergics - benztropine, trihexyphenidyl and procyclidine (watch for side effects esp. with TCAs)
BB for akathisia
Describe antipsychotics atypicals
Serotonin dopamine 2 antagonists
Tend to effect dopamine 1,3,4 and 5 so less EPS
Atypical in the way they affect dopamine and serotonin neurotransmission
Describe risperidone (Risperdal) - antipsychotic
Regular tablets, IM and rapidly dissolving tablet
Function more like a typical at doses greater than 6mg
Increased EPS
Weight gain and sedation
Atypical to induce hyperprolactinemia
Describe olanzapine (Zyprexa) - antipsychotic
Regular tablets, IM, rapidly dissolving tablet and depo form
Weight gain, hypertriglyceridemia, hypercholesterolemia, hyperprolactinemia and hyperglycaemia
May cause abnormal LFTs
Describe Quetiapine (Seroquel) - antipsychotic
Regular tablet
May cause abnormal LFTs
Weight gain, hypertriglyceridemia, hypercholesterolemia and hyperglycaemia
Orthostatic hypotension
Describe Aripiprazole (Abilify) - antipsychotic
Regular tablets, immediate release IM and depo form
Unique mechanism of action as D2 partial agonist
Low EPS, no QT prolongation, low sedation and low weight gain
Describe Lurasidone - antipsychotic
Newer
Similar side effects to aripiprazole
Potential weight gain and increased rate akathisia
Describe treatment resistance for schizophrenia
Poor prognosis to 2 first line antipsychotics at adequate dose for 8 weeks
Clozapine used in this case
When is clozapine used?
Treatment resistant patients as side effect profile
Regular tablet form
What are the side effects of clozapine?
Agranulocytosis, seizures, sedation, weight gain, abnormal LFTs, hypertriglyceridemia, hypercholesterolemia, hyperglycaemia, non-ketotic hyperosmolar coma and death
Describe prophylaxis in psychotic disorder
Relapse more commonly due to non-compliance
Describe anxiolytics
Used to treat panic disorder, generalised anxiety disorder (in combo. with SSRIs and SNRIs), substance related disorder and their withdrawal, insomnias and parasomnias
What are the pros of buspirone - anxiolytics?
Good augmentation strategy in anxiety
5HT1A agonist
No sedation
What are the cons of buspirone?
Takes about 2 weeks before notice results
Will not reduce anxiety in patients that are used to taking BZDs as no sedation effect
Describe benzodiazapines
Used to treat insomnia, parasomnias and anxiety disorders
Also in CNS depressant withdrawal protocols
What are the side effects of benzodiazepines?
Somnolence, cognitive deficits, amnesia, disinhibition, tolerance and dependence
