Flashcards in 12.1 Anti-Psychotics Deck (30)
What is the theory of the mechanism of depression
Caused by a reduction in monoamines (NA, 5HT)
Maybe a loss of receptors
How do we treat Depression?
Mild 1) CBT and Therapy
Moderate/Severe 2) Specific MOA inhibitor e.g. SSRIs
3) Non selective MOA-i e.g TCA, SNRIs
How do we diagnose depression?
How do we grade it?
Need to have 2 or more of: low mood, low energy and lack of enthusiasm for thinks would normally enjoy for at least 2 weeks
We grade it mild, moderate or severe, by secondary symptoms (e.g. suicidal/harmful thoughts, withdrawal from society, previous incidences, FHx)
What is depression?
Depression is a feeling of low mood or lack of energy. It can range from being mild, with mood/cognitive changes, to severe which can experience hallucinations
What are SSRIs?
What do we treat with them?
How do they work?
Selective Serotonin Reuptake Inhibitors
Have a Long Half Life, less withdrawal
Safe in Overdose!
Takes 2 weeks to affect and longer to maximise
ADRs of SSRIs
Increased energy/motivation can cause suicide
Extrapyramidal symptoms - Tremor
GI - nausea, vomiting, diarrhoea
Citalopram can cause Long QT
DDIs with SSRIs
Metabolised by CYP450
Risk of Bleeding with NSAIDs
How do you remember the ADRs of SSRIs?
Sleep - insomnia
Sex - dysfunction
Sweat - anxiety
Stomach - Nausea
What are TCAs?
They act on Muscarinic ACh receptors, Histamine receptors
And they block the reuptake of NA and 5HT
Oral and well absorbed
Variable 1st Pass Effect
Long Half Life
Very Dangerous if OD (arrhythmia, narrow TW)
ADRs of TCAs
Loss of Glandular Secretions (mACh - dry mouth, constipation)
Long QT and Tachycardia
What is an SNRI?
Serotonin Noradrenaline Reuptake Inhibitor
Used for Unipolar Depression
Short Half Life so withdrawal!
ADRs of SNRIs?
Same as SSRIs but more
What is Schizophrenia?
Mental illness with psychotic symptoms
Thought to be caused by an increase in Dopamine
Change in nigrostriatal (extarpyramidal signs), mesolimbic (emotional response), mesocortical (arousal)
Doesn't explain negative symptoms of PS, maybe 5HT /glutamate involved
How do we treat schizophrenia?
How successful is treatment for PS?
1st Gen D2 Antagonists (Ergot Derived)
Atypicals e.g clozapine
1/3 better, 1/3 ok, 1/3 get worse
How do D2 antagonists work?
They block the D2 receptors in the striatum, this inhibits dopamines action on the indirect pathway. This reduces psychotic symptoms
Can cause hyperprolactinaemia
Can lead to Parkinsonism - tardive dyskinesia
Takes days/weeks to work
What are the symptoms of PS?
Hallucinations, Delusions, Disturbed Thoughts/Behaviour
Withdrawal, Anxiety, Unusual Speech
What is an example of a D2 antagonist?
What is an atypical antipsychotic?
An example? Specific ADRs
Have fewer extrapyramidal symptoms so are first line!
Weight Gain (A LOT)
Clozapine - only use in hospital as need to monitor FBC closely
How do we treat anxiety?
CBT and psychological intervention
or antidepressant or antipsychotic may work
May use a benzodiazepine to sedate
What is anxiety?
What NTs are believed to be linked?
Fear which is disproportionate to the situation
Sweating, Pale, Tachycardia, Nausea, Lightheaded
NA, 5-HT, GABA
There is usually a cycle of fear and avoidance, leading to the belief that the only cure is avoidance
How do we use benzodiazepines in anxiety?
Act on GABA receptors to sedate
ADRs with Benzodiazepines?
Drowsy, Hypotension, Teratogenic, Blurred Vision
What do you give if you KNOW it's a benzodiazepine OD?
Flumazenil to antagonise the GABA receptor sites
What is Bipolar Disorder?
What are the signs of mania?
Talking really fast
Can't sit still
What do we treat Bipolar with?
NOT anti-depressants as could worsen mania
Mood stabilisers - Lithium, Anti-epileptics (Sodium Valproate)
ADRs of Lithium
Things to monitor
Lithium is Nephrotoxic (U and E)
Risk in Pregnancy
Thirst and Polyuria
PKs of Lithium
Mechanism of Action?
A: Oral, Once a day
D: Slow release
M: Has a narrow TW (MONITOR)
Competes with Ca2+, Affects 5HT levels
What do you do in a lithium OD?
Support and give fluids