Pharmacological Treatments of Affective and Anxiety Disorders Flashcards
How do antidepressants work?
Don’t fully know
Main neurotransmitters are serotonin and noradrenaline and are increased
Circuit between amygdala, frontal lobe and hypothalamus lights up, indicated important pathway
How good is response rate?
60-70%
NNT 3
What does nnt mean?
Number needed to treat
NNT3 means give to 3 to treat 1
How are antidepressants usually introduced?
Selection based on past history of response, side effect profile and comorbidities
If no improvement is seen after a trial of at least 2 months then change needed
How might antidepressant treatment change if ineffective after trial?
Dose
Switch to different antidepressant
Augment with another agent
Usually refer to psychiatry if 2 medications make no difference
What are some side effects of TCAs?
Weight gain
Sleepy
Dry mouth
Blurred vision
How do TCAs work?
Increasing serotonin, dopamine and noradrenaline
What are some drawbacks of TCAs?
Lethal in OD
Even 1 weeks supply can kill
How might TCAs affect the heart?
QT lengthening
What kind of TCAs are “dirtier”?
Tertiary Tertiary amine side chains cross react with more receptors causing more side effects Amitriptyline Doxepin Clomipramine
How do secondary TCAs usually work?
Block noradrenaline
Desipramine
Nortriptyline
How does monoamine oxidase inhibitors work?
Bind irreversibly to monoamine oxidase
Prevents inactivation of amines like norepinephrine, dopamine and serotonin
What kind of depression is particularly responsive to MAOIs?
Resistant depression
What are some side effects of MAOIs?
Orthostatic hypotension Weight gain Dry mouth Sedation Sexual dysfunction Sleep disturbance
What is Cheese Reaction?
MAOIs taken with tyramine rich food like cheese can result in hypertensive crisis as tyramine isn’t broken down properly
What is serotonin syndrome?
If MAOIs taken with other meds that increase serotonin Abdominal pain Diarrhoea Sweats Tachycardia HTN Pyrexia Death
How do SSRIs work?
Block presynaptic serotonin reuptake
Treat both anxiety and depressive symptoms
What are some side effects of SSRIs?
GI upset Sexual dysfunction Anxiety Restlessness Nervousness Insomnia Fatigue Sedation Dizziness
What is sertraline?
SSRI
What are some consequences of sudden withdrawal of SSRIs?
Discontinuation syndrome Agitation Nausea Disequlibrium Dysphoria
What is a drawback of the short half life of some SSRIs like sertraline?
Symptoms can return quite quickly if medication is missed
Discontinuation syndrome
What is activation syndrome?
Increase in serotonin leading to nausea, increased anxiety, panic, agitation
Typically last 2-10 days
WARN PATIENTS
What is a good option of an SSRI with longer half life?
Fluoxetine
What are some pros for sertraline?
Less drug interactions Short half life Activation can help retardation Easy to stage changes in dose Less sedating
What are some cons of sertraline?
Max absorption requires full stomach
More GI adverse drug reactions
What are some pros of fluoxetine (prozac)?
Longer half life
Helps with discontinuation syndrome
Helps compliance
What are some drawbacks of sertraline?
Long half life may lead to build up
More adverse drug reactions
Initial activation may increase anxiety
More likely to induce mania
What are SNRIs?
Serotonin/Norepinephrine reuptake inhibitors
Inhibit both serotonin and noradrenergic reuptake
Venlafaxine
What are some pros of SNRIs?
Less antiadrenergic and anticholinergic side effects of TCAs
Short half life
What are SNRIs used for?
Depression
Anxiety
Neuropathic pain
What are some drawbacks of venlafaxine?
Raised BP Nausea Discontinuation syndrome Prolonged QT Sexual dysfunction
What are some pros of duloxetine?
Treats some physical symptoms of depression
Less likely to raise BP
What are some drawbacks for duloxetine?
Some interactions in liver
Active ingredient not stable in stomach so can’t break capsule
What is mirtazipine?
Novel antidepressant
What is mirtazapine used for?
Good augmentation for SSRIs as different mechanism
Sedative so can be useful in substance abuse
What are some side effects of mirtazapine?
Increased cholesterol
Weight gain
Very sedating
What is a significant contraindication for TCAs?
Previous suicide attempts
What are some options to overcome treatment resistance?
Start on SSRI Move to SNRI Add mirtazapine Adjunctive lithium Adjunctive atypical antipsychotic like quetiapine or aripiprazole ECT
What are some considerations for treating anxiety?
Serotonergic treatment preferable
Avoid symptomatic relief like diazepam
When are mood stabilisers indicated?
Bipolar disorder
Cyclothymia
Schizoaffective disorder
What are some different classes of mood stabilisers?
Lithium
Anticonvulsants
Antipsychotics
Which medication is the only which reduced suicide rates?
Lithium
How is lithium used?
Reduces suicide rate in bipolar affective disorder
Effective in long-term prophylaxis for mania and depressive episodes
What might predispose to good lithium response?
Prior long-term response for patient or family member
Classic pure mania or if mania followed by depression
What are some tests to do before starting lithium and why?
U&E and TSH and pregnancy in women
Affects renal function and can affect thyroid function
Why should a patient get a pregnancy test before starting on lithium?
Associated with Ebstein’s anomaly in first trimester
20x greater risk
What are some side effects of lithium?
Reduced appetite Nausea Diarrhoea Hypothyroid Leukocytosis Polyuria/polydypsia Renal fibrosis leading to renal failure Hair loss Acne Reduces seizure threshold
Why might lithium not be good for epileptics?
Reduces seizure threshold
What are some consequences of lithium toxicity?
Vomiting Diarrhoea Ataxia Dizziness Slurred speech Nystagmus Blurred vision Clonic limb movements Convulsions Delirium Syncope Oliguria Renal failure
What is valproic acid?
Anticonvulsant
What is valproic acid good for?
Mania prophylaxis Rapid cycling patients Comorbid substance issues Mixed patients Comorbid anxiety Better tolerated than lithium
Why is valproic acid avoided in child bearing age?
Neural tube defects
What are some tests to do before starting valproic acid?
LFTs
FBC
Pregnancy
What are some side effects of valproic acid?
Thrombocytopenia Platelet dysfunction Nausea/vomiting Weight gain Sedation Tremor Hair loss
What is carbamazepine used for?
First line agent for acute mania and mania prophylaxis
What are some tests to be done before starting carbamazepine?
FBC
LFTs
ECG
What are some carbamazepine side effects?
Rash Nausea, vomiting, diarrhoea Sedation, dizziness, ataxia, confusion AV conduction delays Aplastic anaemia Water retention
Why is ECG required before starting carbamazepine?
Risk of AV conduction delay
How does carbamazepine cause water retention?
Vasopressin-like effect
Can result in hyponatremia
What is lamotrigine used for?
Neuropathic pain
Bipolar depression
What are some serious side effects of lamotrigine?
Steven Johnstone syndrome (serious rash less common with slow titration)
What would be a good med for manic episodes with alcohol abuse?
Depakote (anticonvulsant)
Rapid cycler
Is LFT rising in anticonvulsants concerning?
No
Pretty common
Unless its excessive (3x) you can just monitor
What would be most likely treatment for a violent, sexually disinhibited patient brought in by police for detention?
IM meds with sedation
Antipsychotic (olanzapine) and benzodiazepine (lorazepam)
Mood stabiliser once condition stable
How are phobias managed?
CBT/exposure therapy
Benzodiazepines in short-term crisis
SSRI antidepressants may help
How are panic disorders managed?
CBT
Add SSRI if CBT response inadequate
TCA like clomipramine or imipramine may be tried after 3 months
What is the first choice drug to treat GAD if requested or indicated?
Sertraline
SNRI like venlafaxine or duloxetine if sertraline fails
What is the first line treatment for OCD?
CBT
What is the second line treatment for OCD?
SSRI antidepressants
What is the best treatment for PTSD?
Trauma-focussed CBT
