Depression drugs Flashcards
(23 cards)
Features of depression?
low mood, low energy, loss of libido, sleep disturbance.
What is unipolar depression?
Mood swings into depressive moods only
What is bipolar depression?
mood swings between depressed and manic (enthusiastic, exuberant)
Monoamine theory of depression?
low levels of monoamines : 5HT. NA and dopamine in the brain induces depression
What is the neuroendocrine theory of depression?
Hyperactive Hypothalamic pituitary axis leads to excess cortisol. Low activity of hippocampus induces depression.
what is the neuroplasticity /neurogenesis theory of depression?
neuronal loss and decreased activity in hippocampus causes less ‘happy’ signals to be sent
Main theory?
Monoamine
Two main treatments of depression?
CBT and antidepressants
What is CBT
Cognitive behavioural therapy - helming depressed people think about their thoughts in more manageable positive ways, changing the way people think.
Three types of ADs?
MAOIs, TCAs and SSRIs
How do MAOIs work?
prevent MAO breaking down Was- NA and 5HT, therefore higher level in synaptic cleft.
Problems with MAOIs?
Sympathomimetics cause an increased release of NA- excess will not be broken down as MAOs are inactivated and this causes TOO much NA- causes headaches, intracranial haemorrhage and hypertension.
Side effects of MAOIs?
Headaches, hypertension, tremors, convulsions, dry mouth, antimuscarinic effects .
Mechanism of TCAs?
Block re uptake of NA and 5HT by re uptake transporters.
Problems with TCAs?
Anti cholinergic and anti muscarinic effects- dry mouth , constipation, drowsiness, have other drug interactions. narrow therapeutic window, OD is toxic, and cause respiratory depression.
Side effects of TCAs?
Anti muscarinic and anti cholinergic - drowsiness, constipation and blurred vision. Block K channels - respiratory depression and exaggerate heart problems.
Mechanism of SSRIs?
Block uptake of 5HT channels, inhibit the 5HT neurone causing increased 5HT release- increases 5HT in synaptic cleft, ‘normalising the post synaptic neuron to a normal working level.
Problems with SSRIs?
Take 2-3 weeks to work, linked to violence in U18s, can’t be used with TCAs or MAOIs
Side effects of SSRI’S?
insomnia, sexual dysfunction, nausea.
Benefits of SSRIs?
broader therapeutic profile- treats GAD, anxiety and OCD too.
Other antidepressants?
mirtazapine - alpha 2 antagonist
How do alpha 2 antagonists treat depression?
Alpha 2 receptors are on the pre synaptic neurone- once activated by NA they stop the release of further NA and 5HT, antagonists stop this negative stimulus, increasing NA and 5HT release from pre synaptic neurone.
Main issues with ADs?
Can become addictive, insomnia, toxic in OD, delayed response, unresponsive in some, have pharmacogenetics interactions within the body.
