psychopharmacology in psychiatry Flashcards
How long after prescribing antidepressants is an affect noticed
2-4 weeks
What are antidepressants used for
Unipolar and bipolar depression, organic mood disorders, schizoaffective disorder, anxiety disorders including OCD, panic, social phobia, PTSD
how do Selective serotonin reuptake inhibitors (SSRIs) work
Block the presynaptic serotonin reuptake
What are the side effects of SSRIs
- GI upset
- sexual dysfunction
- anxiety
- restlessness
- nervousness
- insomnia
- fatigue
- sedation
- dizziness
What is activation syndrome and what are the symptoms
starting SSRIs causing increased serotonin in the brain with the medication which can cause nausea, increased anxiety, panic and agitation - lasts 2-10 days
What drug is used when trying to avoid discontinuation syndrome
Fluoxetine (Prozac) - due to long half life
What are the cons of sertaline
GI adverse reactions and needs a full stomach for max absorption
How do monoamine oxidase inhibitors (MAOIs) work
bind irreversibly to monoamine oxidase, preventing inactivation of amines such as norepinephrine, dopamine and serotonin leading to increased synaptic lebels
What are the side effects for MAOIs
Orthostatic hypotension, weight gain, dry mouth, sedation, sexual dysfunction and sleep disturbance
How does serotonin syndrome occur
MAOIs taken with serotonin increasing meds
What are the symptoms of serotonin syndrome
Abdo pain
Diarrhoea
Irratibility
Sweats
Tachycardia
HTN
myoclonus
How to avoid serotonin syndrome
Wait 2 weeks before switching from an SSRI to a MAOI - 5 weeks if fluoxetine
How do Serotonin/Norepinephrine reuptake inhibitors work
Inhibit both serotonin and noradrenergic reuptake like the TCAS but without the antihistamine, antiadrenergic or anticholinergic side effects
What needs to be done before prescribing lithium
Baseline U+Es and TSH
Pregnancy test as tetranogenic in first trimester
What is the con with Mirtazapine
Associated with weight gain
What can duloxetine help with
Neuropathic pain
Depression
Anxiety
How is treatment resistant depression treated
- Combination of antidepressant like an SSRI or SNRI with Mirtazepine
- Adjunctive treatment with lithium
- Adjuctive treatment with atypical antipsychotic - quetipaine, olanzapine or aripiprazole
What is the treatment ladder for treatment resistant anxiety
- High dose SSRI
- Add on Mirtazapine with an SSRI or SNRI
- Adjunctive treatment with atypical antipsychotic - quetipane, olanzapine
- Adjuctive treatment with pregabalin or buspirone
How long to continue treatment after first depressive or anxiety episode
6 months - 1 year prophylaxis
How long to continue treatment after second depressive or anxiety episode
2 years prophylaxis
How long to continue treatment after third depressive or anxiety episode
Life long prophylaxis
What are examples of TCAs
Imipramine
Amitriptyline
Doxepin
Clomipramine
Desipramine
nortriptyline
What are mood stabilizers used for
Bipolar
Cyclothymia
Schizoaffective disorder
What is the only drug that reduces suicide rate
Lithium
What is lithium effective at treating
Prophylaxis of mania and depressive episodes
What are the signs that lithium will be effective
Familt member used it with good response
Classic pure mania
Mania followed by depression
What is the goal blood level of lithium during lithium treatment
0.6 - 1.2
What are the side effects of lithium
- GI distress such as diarrhoea and reduced appetite
- Thyroid abnormalities
- Polyuria/polydypsia
- Hair loss
- Acne
- Cognitive slowing
- Intention tremor
What is seen when lithium levels reach 1.5-2 - mild lithium toxicity
- vomiting
- Diarrhoea
- ataxia
- dizziness
- slurred speech
- nystagmus
What is seen in moderate lithium toxicity - 2-2.5
Nausea
vomiting
anorexia
blurred vision
chronic limb movements
convuslions
delireum
What is seen in severe lithium toxicity >2.5
Generalised convulsions
Oliguria
Renal failure
What is valproic acid effective for
Mania prophylaxis but not depression prophylaxis
When should valproic acid be avoided
Woman of child bearing age due to neural tube defects which can occur
What are the side effects of valproic acid
Thrombocytopenia and platelet dysfunction
Nausea, vomiting, weight gain
Sedation, tremor
Hair loss
What is the first line agent for acute mania and mania prophylaxis
Carbamazepine
What are the side effects of carbamazepine
Rash - most common
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!
Why is lamotrigine titrated very slowly
If given high dose at once, can cause Steven Johnsons syndrome - if any rash develops ithe lamotrigine is stopped immediately
What are the side effects of lamotrigine
Nausea
vomiting
sedation
dizziness
ataxia
confusion
Steven Johnson syndrome
What can happen to the LFTs due to anticonvulsants
increase - not worrying unless it more than triples
What are antipsychotics used for
Schizophrenia
Schizoaffective disorder
Bipolar
Mood stabilisation
Psychotic depression
What can reduced dopamine cause
Parkinsonian movements such as rigidity, bradykinesia and tremors
What are typical antipsychotics
D2 dopamine receptor antagonistics
What are the side effects of antipsychotics
Tardive Dyskinesia (TD)-involuntary muscle movements that may not resolve with drug discontinuation- risk approx. 5% per year
Neuroleptic Malignant Syndrome (NMS): Characterized by severe muscle rigidity, fever, altered mental status, autonomic instability, elevated WBC, CPK and lfts. Potentially fatal.
Extrapyramidal side effects (EPS): Acute dystonia, Parkinson syndrome,
Akathisia be aware increased risk of suicide
What should be given for the extrapyramidal side effects when using antipsychotics
- Anticholinergics - benztropine, trihexyphenidyl or procyclidine
- Beta blockers like propanalol
What do atypical antipsychotics do
Serotonin dopamine 2 antagonists
What are the side effects of risperidone - atypical antipsychotic
Hyperprolactinemia
Weight gain
Sedation
What is teh significant side effects of olanzapine
Atypical antipsychotic:
Significant weight gain
Hyperprolacinemia - less chance then risperidone
Abnormal LFTs
Define treatment resistant schizophrenia
Poor response to 2 first line antipsychotics at an adequate dose for 8 weeks
What is given for treatment resistant schizophrenia
Clozapine
What are the side effects of clozapine
Agranulocytosis
Increased risk of seizures
Sedation
Weight gain
Abnormal LFTS
Increased risk of hypertriglyceridemia, hypercholesterolemia, hyperglycemia, including nonketotic hyperosmolar coma and death with and/or without weight gain
Increased saliva production
What is the most common psychotic symptom
Lack of insight
