Psychopharmacology for Psychiatry Flashcards
What are the 3 classifications of medicines in psychiatry?
WHO chemical
Diagnostic
New NbN system - neuroscience based nomenclature
What are the 4 types of treatment in medicine?
Give examples in psychiatry for each:
Chemical - drugs / medicines (+immunotherapy) e.g. anti-depressants
Electrical stimulation e.g. ECT for depression
Structural rearrangement - surgery and orthopedics e.g. psychosurgery / deep brain stimulation for severe depression
Talking (psycho) therapies e.g. CBT
How are psychiatric drugs classified by the WHO classification system?
What are the pros and cons of this system?
Based on chemical structure
Pro = each drug has a unique structure = easy to allocate data
Con = no use in clinical decision making
How are psychiatric drugs classified based on diagnostics (i.e. what illness they treat)?
What are the pros and cons of this system?
E.g. anti-depressants, anti-psychotics, anxiolytics, anti-hypnotics
Pros = easy for doctors to choose a drug as doctors make diagnoses
Cons = many psychiatric medicines work in several disorders, and most psychiatric disorders have multiple symptoms and a single medicine might not treat them all
How are psychiatric drugs classified based on NbN?
NbN = Neuroscience based Nomenclature
The core pharmacology is used to classify medicines i.e. based on their target neurotransmitters
e.g. instead of antipsychotic, dopamine blocker
instead of antidepressant, serotonin enhancer
instead of hypnotic, GABA enhancer
What are the 4 possible systems on which medicines in psychiatry can act on?
- Receptors
- Neurotransmitter reuptake sites
- Ion channels
- Enzymes
Why do these medicines have side effects?
Because the target sites are found in the brain and around the body
When the drug acts on the target sites around the body outside the brain, it may cause side effects
What are some examples of drug treatments that block enzyme activity?
What are they used to treat?
MAOIs = block breakdown of serotonin and noradrenaline - anxiety and depression
Acetylcholinesterase inhibitors = block breakdown of ACh - dementia
Lithium = blocks glycogen synthase - mood stability (stabilises neurones)
What are some examples of drug treatments that are receptor blockers (antagonists)?
What are they used to treat?
Dopamine receptor blockers - SZ
Serotonin receptor subtype antagonists - depression
Histamine receptor antagonists - sleep
What are some examples of drug treatments that simulate receptors / enhancers (agonists)?
What are they used to treat?
Benzodiazepines = enhance GABA - sleep / reduce epilepsy
Guanfacine = enhance noradrenaline - ADHD
What are some examples of drug treatments that block reuptake sites?
What are they used to treat?
Citalopram (SSRI)= enhance serotonin - depression and anxiety
Desipramine (NRI) = enhance noradrenaline - depression
Methylphenidate (DRI) = enhance dopamine - ADHD
What are some examples of drug treatments that switch the reuptake site direction to enhance release of NTs?
What are they used to treat?
Amphetamines = enhance dopamine - ADHD
What are some examples of drug treatments that act to block ion channels?
What are they used to treat?
Sodium channel blocks = reduce no. of neurons firing
Sodium valproate - epilepsy and mood stabilisation
Carbamazepine - epilepsy and mood stabilisation
Calcium channel blocks = reduces excitability in the brain
Gabapentin and Pregabalin - epilepsy, anxiety
What are 2 types of neurotransmitters (NTs)?
Fast-acting (on-off switch)
Slow-acting (modulators)
What are fast-acting NTs?
Amino acid NTs
Excitatory = glutamate = present in >80% of all neurons Inhibitory = GABA = make up 15% of the brain's neurons called interneurons
Balance of these two = responsible for memory, movement, vision etc.
