Antidepressants Flashcards
Broad mechanism of action of most antidepressants
Increase synaptic availability of neurotransmitter
Precursor amino acid for synthesis of serotonin
Tryptophan
Drug classes which interfere serotonin neurotransmission
AntidepressantsAnti-migraineAnti-pyschoticsAnxiolyticsAnti-emetics
Mechanism of action of citalopram, sertraline,fluoxetine
Selective serotonin re-uptake inhibitors (SSRIs)-increase 5-HT availability in the synaptic cleft
Why do SSRIs generally have fewer side effects than TCAs?
Are serotonin-selective- have no effect on noradrenaline uptake, and cause less blockade of other receptors
Indications for SSRIs
Moderate to severe depression (and mild, where psychological therapy has failed)Panic disorderObsessive compulsive disorder+ many more
Common adverse effects of SSRIs
Gastrointestinal upsetAppetite and weight disturbanceMay increase suicide/self harm risk in young people in first few weeks
When should SSRIs be prescribed with caution?
People with epilepsy- can lower the seizure thresholdPeople with peptic ulcer disease- can increase bleedingYoung people- have poorer efficacy,and risk of self harm
Which classes of drug should SSRIs not be prescribed with?
Drugs which prolong the QT intervalMonoamine oxidase inhibitors
Indications for TCAs
Second line treatment of depression where SSRIs have been ineffectiveNeuropathic pain
Mechanism of action of TCAs
Block 5-HT and NA re-uptake, as well as blockade of various other receptors
Why is clinical utility of TCAs limited?
Blockade of various receptors causes a wide variety of potential adverse effects
Antimuscarinic side effects of TCAs
Dry mouthConstipationUrinary retentionBlurred vision
Cardiac side effects of TCAs
Postural hypotension (interferes with orthostatic reflexes- cholinergic and adrenergic blockade)
Indications for venlafaxine (other than depression)
Anxiety disorder
