Systemic Drugs - CNS Flashcards
what % of the population take CNS drugs
25
How many people have mental health problems?
1/3 of the population : depression has the highest prevalence (like me studying)
1/250 also have psychotic illness this includes Bipolar affective disorder and schizophrenia
How does the GP diagnose depression?
- subthreshold depression : less then 5 symptoms (normal mood changes)
- Mild : just north of 5 symptoms and minor functional impairment
- moderate depression (area between mild and severe)
- severe : have most of the symptoms, including with and without psychotic symptoms, interfere with functioning
what is watchful waiting?
the px does not want intervention / mild depression we dont give intervention we just keep an eye.
Exercise and light therapy will help a px with mild dep
What are two low-intensity psychological therapy interventions?
CBT (cognitive behaviour therapy) - group intervention
CCBT (computerised cognitive behavioural therapy) - group online
We give CBT/CCBT to mild depressed px, what do we give to moderate/severe depressed px? (OR someone who has been subthreshold depressed for a long time)
DRUGS
How do we prescribe drugs for severe/ moderate , prolonged subthreshold px?
- Look at past experience - if they have any
- px choice
- Look for any side effects (BNF) or chance of them using the drug to hit the hay permanently (suicide)
What is the therapeutic aim of these drugs?
maintain the levels of monoamine neurotransmitters in the brain ;
- serotonin (5-HT) (SSRI / TCA)
-noradrenaline (TCA)
- dopamine
How do Selective serotonin reuptake inhibitors work?
- The will bind to 5-HT transporter protein
- This prevents them going back to the presynaptic neuron for retake up
- Maintains 5-HT level in the synaptic cleft so increases likelihood of binding to the target
What are four examples of SSRI?
Citalopram (cipramil)
Escitalopram (cipralex)
Fluoxetine (Prozac)
Paroxetine (seroxat)
How does TCA work?
Same as SSRI but also works on noradrenaline toooo.
There is accumulation of 5-HT and noradrenaline too
They are not first line though, we start with SSRI
What is an advantage to TCA?
long half life = helps px sleep too
Which one do we pick TCA vs SSRI?
Look at adverse effects on the profile of the drug… see if the px is suitable
SSRI is safer as overdose wont be as harmful
SSRI is first time
What are four examples of TCA?
Amitriptyline, clomipramine , imipramine, lofepramine
what’s Venlafaxine and Duloxetine?
Next gen drugs, work similar to TCA but different chem structure
SO these or TCA?? Look at the price and side effects
what is monoamine oxidase A?
Enzyme which breaks down amines ; 5-HT and noradrenaline
It converts them into their carboxylic acid.
Look at the diagram on the slide:
- In the presynaptic neuron you can see the inhibitor preventing the break down of the monoamines… this means there is more monoamines neurotransmitter available
why is there limitations on Monoamine oxidase inhibitors?
Dietary restrictions : Amino acid Tyramine, found high conc in cheese.
Examples of MAOI
- Phenelzine
- Isocarboxazid
- Moclobemide
- Isocarboxazid
What are hypnotics?
They are drugs which help with insomnia (sleep is 4 the weak though)- SHORT TERM MANAGEMENT (due to its addictiveness)
Two examples of hypnotics: benzodiazepines and Non-benzothiazines, name some examples of each type.
Benzodiazepines: short half life
- Nitrazepam
- Flurazepam
Non- benzodiazepine:
Zopiclone
what is anxiolytics?
short term relief of anxiety that is causing px distress. short term = 2-4 weeks
What are three Examples of anxiolytics?
Benzodiazepines: longer half-life and muscle relaxers
- Lorazepam
- Diazepam
- Oxazepam
why do we use hypnotics and antiolytics short term?
they are addictive as fuck and we do not want the px to become reliant on them, it will just mask the problem and not solve it.
So what is a benzodiazepine (We have these types of drugs available for hypnotics and anxiolytics)?
- they enhance the binding site of GABAa (receptor for GABA)
- Enhance effectiveness therefore MORE inhibitory
** GABA is a inhibitory ball
What are the two classifications of antipsychotics/ neuroleptics/tranquiller?
Typical and Atypical
what does the Typical (conventional) antipsychotic drug work on?
Dopamine receptors. But why isn’t dopamine good ?? Yes, but an unnaturally elevated amount of dopamine s linked to psychosis.
SO this is how it works:
- The Typical drug will block the D2 receptor on the post synaptic membrane
what other effects can typical antipyschotic drugs have?
- cholingeric, histaminergic, stasdklvjnaslkjdvnfaskjdn
What are the side effects of typical antipsychotics?
sedations, Extrapyramidial effects (like Parkinson’s) and anticholinergic effects (dry mouth ect)
Name three Typical antipsychotic drugs
1) Phenothiazines: chlorpromazine
2) Thioxanthene’s: flupentixol
3) Butyrophenones : Haloperidol
What do Atypical drugs do and what do they act on?
Same shit as typical but they also act on other receptors (typical = only dopamine and the D2 receptor)
they are less likely to cause side effects compared to typical
What five examples of Atypical drugs?
Amisulpride(solian)
Clozapine(Clozaril)
Olanzapine (Zyprexa)
Quetiapine (Seroquel)
Risperidone(Risperdal)
What is bipolar affective disorder
Dramatic mood swings. We can use DRUGS to control acute attacks and also prevent their recurrence
Name the drugs we use for Bipolar affective disorder : for acute attacks and for prophylaxis
Acute attacks:
- Benzodiazepines
- Antipsychotics
Prophylaxis:
Lithium (Priadel)
Antiepileptic drugs - this is a big que card, just learn everything on this.
Epilepsy can be spontaneous or following a brain trauma , stroke.
* Carbamazepine * Lamotrigine * Sodium valproate
Ocular adverse side effects, but not prescribed commonly
* Vigabatrin
- Topiramate
Which group makes the guidelines for recommendations for the treatment and management of depressions?
NICE guidelines
Which types of drugs are recommended as first line treatment for depression?
SSRIs (Selective serotonin reuptake inhibitors) - they are as effective as tricyclic anti-depressants but safer in overdose
Which is safer in overdose- TCAs or SSRIs?
SSRIs
What are four examples of monoamine neurotransmitters?
- Serotonin
- Noradrenaline
- Dopamine
- Adrenaline
What is depression associated with?
Reduced levels of monoamine neurotransmitters in the brain (serotonin, noradrenaline and dopamine)
What is the main objective of antiepiletics?
Object of treatment is to prevent epileptiform event (seizures) by preventing the depolarisation of neurones (inhibition of excitatory neurones, direct membrane stabilisation, stimulation of inhibitory neurones)
What is an epileptiform event?
A seizure- excessive depolarisation of cerebral neurones which can be localised or spread
