Psychopharmacology Flashcards
What basis is selection of antidepressants based upon?
Generally no difference in efficacy so based on: -Any past history of response -Side effect profile -Coexisting medical conditions
How long does it take for symptoms to improve when an antidepressant is diagnosed? What should be done if symptoms do not improve?
Delay of 3-6 weeks after a therapeutic dose is reached before symptoms improve. If no improvement is seen after prescription of an adequate dose for at least two months then the treatment should be switched to another agent or augmented with one
What are the classes of antidepressant?
Tricyclics (TCAs) Monoamine Oxidase Inhibitors (MAOIs) Selective Serotonin Reuptake Inhibitors (SSRIs) Serotonin/Noradrenaline Reuptake Inhibitors (SNRIs) Novel antidepressants
What is the mechanism behind tertiary TCAs?
Act on serotonin receptors
What are the side effects of tertiary TCAs?
Antihistaminic Anticholinergic Antiadrenergic QT lengthening
What are some examples of tertiary TCAs?
Amitriptyline Clomipramine Imipramine Doxepin
When should tertiary TCAs be avoided and why?
In high risk suicide patients as they can be taken in overdose
What is the mechanism behind secondary TCAs?
Block noradrenaline
What are the side effects of secondary TCAs?
Similar to tertiary TCAs but less severe
What are some examples of secondary TCAs?
Desipramine Nortriptyline
What is the mechanism behind monoamine oxidase inhibtors?
Binds irreversibly to monoamine oxidase, preventing inactivation of amines (norepinephrine, dopamine, serotonin) and so increases synaptic levels
What are the side effects of monoamine oxidase inhibitors?
Antiadrenergic side effects Antihistaminic side effects Dry mouth Sleep disturbance Hypertensive crisis if eating tyramine rich foods (cheese, red wine, processed meats, beans) Serotonin syndrome (more info below) can develop if also taking meds that increase serotonin/have sympathomimetic actions
What are some examples of monoamine oxidase inhibitors?
Phenelzine Tranylcypromine Selegiline
In what situation is a monoamine oxidase inhibitor most effective?
Treatment resistant depression
What mechanism is behind selective serotonin reuptake inhibitors?
Blocks presynaptic serotonin uptake
What are the side effects of selective serotonin reuptake inhibitors?
GI upset (most often nausea) Sexual dysfunction (most common reason for discontinuation by patient) Anxiety Restlessness Nervousness Insomnia Fatigue/sedation Dizziness
What are some examples of selective serotonin reuptake inhibitors?
Paroxetine Sertraline Fluoxetine Citalopram Escitalopram Fluvoxamine
What are the symptoms of SSRI discontinuation syndrome?
Agitation Nausea Disequilibrium Dysphoria Usually lasts 7-10 days
What is the mechanism behind serotonin/norepinephrine reuptake inhibitors (SNRIs)?
Inhibits both serotonin and noradrenergic reuptake like TCAs
What are some examples of SNRIs?
Venlafaxine Duloxetine
What are the possible uses of SNRIs?
Depression Anxiety Neuropathic pain
What is the mechanism behind mirtazapine?
Different mechanism of action may provide good augmentation for SSRIs Can be used as hypnotic at lower doses
What are the side effects of mirtazapine?
Increases serum cholesterol Sedative at low doses Weight gain
What are the side effects of buproprion?
Seizure risk at high doses Anxiety Agitation Insomnia Psychotic side effects at high doses
What are the contraindications of buproprion?
Traumatic brain injury Bulimia Anorexia
What are the symptoms of serotonin syndrome?
Abdominal pain Diarrhoea Sweats Tachycardia Hypertension Myoclonus Irritability Delirium
What are the potential complications of serotonin syndrome?
Hyperpyrexia Cardiovascular shock Death
How is serotonin syndrome prevented?
Wait for two weeks when switching from an SSRI to an MAOI, with the exception of fluoxetine where you need to wait for five weeks due to the long half-life