Antidepressants Flashcards
Which 2 monoamine Nts affect depression
5HT and nadr
Where is n adr produced in the brain
Locus (cell bodies)
Where is 5 HT produced
Raphe nuclei
Which 3 areas does 5HT and nadr from brain travel to
Cortex
Hypothalamus
Hippocampus
What is the pre cursor for 5HT at the raphe nuclei
Tryptophan
How is tryptophan converted to 5HT
Trp hydroxylase
This produced 5 HTP
5HTP decarboxylase converts it to
5HT
What is the full metabolism of nadr like
Nadr
Converted to
DOPEG via MAO and aldehyde dehydrogenase
From DOPEG to MHPG via catechol o methyl transferase
How is 5HT metabolised
Into aldehyde via MAO
Into 5H IAA
Via aldehyde dehydrogenase
Which line of 5HT receptors are inhibitory
5HT1
Which 5HT receptors are stimulatory and how
5HT2
They are gpcr which activate the Phospholipase system
which 5HT receptor is ligand ion channel receptor
5HT3
What is the auto receptor for nadr and also for 5HT
Nadr - A2
5HT - 5HT1B
What do autoreceptors at the cell bodies eg focus and the raphe nuclei do
Inhibit firing and release of nadr and 5HT
Which 5HT receptor is an auto receptor which inhibits firing from cell body and how
5HT1 a
Causes opening or K* channels which causes hyperpolarisation
Which reuptake transporters are used
High affinity reuptake transporters
Which 2 drugs suggested increased 5HT and nadr reduce depression
MAOI and reuptake inhibitors
What is an issue with using MAOI to increase 5HT and nadr
Decreases the metabolism of DA and amines which then cause sympathomimetic effects like hypertension
What are the 2 types of reuptake inhibitors
SSRI
Tricyclic antidepressants
What do tricyclic inhibit reuptake of
Both 5HT and nadr
What are 3 side effects of the tricyclic reuptake inhibitors
Muscarinic antagonists- can cause things like dry mouth
H1 antagonists - causes sedation
A1 antagonists - causes hypotension (loss of vasoconstriction)
What is serotonin syndrome
Too much serotonin eg due to MAOI and SSRI can cause malignant hyperthermia (over heating)
Why do antidepressants not work till few weeks after
1- auto receptors need time to desensitise to start to increase firing from cell body to release 5HT and nadr
2- synaptic plasticity via 5HT takes time which then causes normal mood
