Depression - 123 Flashcards
What do MAOIs interact with?
Cheese-reaction - mature cheese, beer, pickled herring, soy extracts, yeast.
Ephedrine containing products
Pethidine
What antidepressant requires a 2 week ‘washout’ period before the patient can start other antidepressants?
MAOIs
What is the mechanism of action of MAOIs? What are the 2 subtypes and their binding preferences?
Inhibit MAO.
MAO-A and MAO-B.
MAO-A prefers serotonin, MAO-B prefers dopamine
What is serotonin syndrome?
A potentially fatal drug reaction that can occur after taking drugs such as SSRIs. Excess serotonin activity produces a spectrum of symptoms such as: increased HR, shivering, sweating, high BP, agitation, confusion etc.
What is the mechanism of action of TCAs?
Inhibit the reuptake of serotonin and noradrenaline from the synaptic cleft.
What are some adverse effects that TCAs can cause?
Sedation, postural hypotension, tachycardia, arrhythmias, dry mouth etc.
What are TCAs contraindicated in?
recent MI, heart block, narrow angle glycoma.
What class of antidepressant is Dosulepin and when should it be prescribed?
TCA. It shouldn’t be!
What would the first line antidepressant treatment usually be?
Citalopram, a SSRI.
Does addiction occur with antidepressants? Name 2 drugs addiction occurs with.
No
Benzodiazepines - diazepam, temazepam.
What are the 2 categories of benzodiazepines?
Hypnotics and anxiolytics.
How long does tolerance take to develop with benzodiazepines?
Between 3-14 days of continuous use
Name 2 SSRIs and adverse effects they can cause.
Fluoxetine (prozac) and citalopram.
Nausea, anorexia, insomnia, GI problems, loss of libido, serotonin syndrome, hyponatraemia.
What are contraindications for SSRIs?
<18 years due to the increased risk of self harm.
What does Venlafaxine do?
5-HT reuptake inhibitor, used in severe depression. Has the greatest risk of death in overdose but also greatest efficacy.
What is the main excitatory neurotransmitter in the CNS? What does prolonged activation of these receptors cause?
Glutamate
Hyper-excitability - seizures etc.
What is the main inhibitory neurotransmitter in the CNS?
GABA, 2 types, GABAa (fast inhibition) and GABAb
What happens if you activate GABAa receptors and what drug does this?
Causes sedation - lorazepam (benzodiazepine). Alcohol also does this.
What happens if you block GABAa receptors?
Hyper-excitability and seizures.
On what principle does date rape with flunitrazepam (Rohypnol) work?
Benzodiazepines active GABAa receptors and cause sedation. Alcohol also causes sedation. If the 2 are mixed together the effects are additive and only small quantitates of each are needed.
Name 4 types of glial cell and what they do
Astrocytes - neuronal support and damage repair
Oligodendrocytes - myelination
Microglia - macrophages of nervous system
Ependymal cells - make CSF
Glial cells take up GABA from the synapse.
What kind of neurotransmitter is glycine? Where is it mostly active?
Inhibitory. Brain stem and spinal cord
Where is most of the serotonin in the body stored?
Enterochromaffin cells which line the GI tract. It is involved in peristalsis there.
Enterochromaffin cells are sensitive to chemo and radiotherapy.
What are the source of serotonin release in the brain?
Neurones in the raphe nuclei
