Drugs Used in CNS Flashcards
1
Q
Common psychiatric conditions
A
- Anxiety disorder
- Insomnia
- Depressive disorder
- Psychosis
2
Q
Symptoms of anxiety disorders
A
- Psychological symptoms
- apprehension, fear - Somatic symptoms
- CVS - palpitations, tremors
- Resp - chest pain, SOB
- GIT disturbances, hyperactivity
- Headaches, dizziness
- Loss of libido
- Muscle spasms
- Insomnia
3
Q
Definition of insomnia
A
inability to fall asleep, maintain sleep or early morning wakening, affecting the function of the next day
4
Q
Causes of insomnia (3)
A
- Anxiety - increased emotional arousal
- Drug induced, caffeine
- Drug withdrawal - after chronic use of alcohol, sleeping pills
5
Q
Drugs used for anxiety disorders & insomnia
A
- Benzodiazepines
- Short Acting: Midazolam
- Intermediate Acting: Lorazepam, Alprazolam
- Longer Acting: Diazepam - Non-benzodiazepine hypnotics
- Zolpidem, Zopiclone
6
Q
Mechanism of action of benzodiazepines
A
- BZD binds to specific BZD sites in the CNS
- increased freq of Cl channel opening - potentiates GABA actions
- GABA dependent, overdose is safe
- GABA is also an inhibitory neurotransmitter - helps sleep - faster onset but reduced REM & deep (stage 4) sleep compared to natural sleep (poorer quality)
7
Q
Toxicity of benzodiazepines (6)
A
- CNS - increased drowsiness, decreasd motor skills, prolonged reaction time
- CNS - anterograde amnesia esp after IV sedation
- CVS - decreased BP & resp rate
- Paradoxical effects - excitement, garrulousness, irritability, hallucinations, outburst of rage (attributed to disinhibition by BZD)
- Neonatal toxicity - floppy child syndrome
- Tolerance, dependance, withdrawal
8
Q
Toxicity of non-benzodiazepine hypnotics (2)
A
- Withdrawal anxiety
2. Abuse potential
9
Q
Symptoms of depression (6)
A
- Decreased mood, interest
- Feeling of shame, guilt
- Suicidal ideation
- Less sleep/appetite (or more - atypical depression)
- Psychomotor retardation
- Decreased concentration, energy
- symptoms persist for at least 2 weeks
- severity of symptoms interfere with normal functioning
10
Q
Non pharmacological treatment of depression
A
- Psychological - cognitive behavioural therapy, interpersonal
- Social, behavioural, relaxation, counselling
11
Q
Pharmacological treatment of depression (4)
A
- Selective serotonin re-uptake inhibitors (SSRIs)
- Fluoxetine, Escitalopram, Sertraline, Paroxetine - Tricyclics (TCAs)
- Amitriptyline, Imipramine - Serotonin norepinephrine re-uptake inhibitors (SNRIs)
- NaSSa - noradrenergic & specific serotonergic antidepressants
12
Q
Mechanism of action of antidepressants
A
- block re-uptake transporters
- enables neurotransmitters present in synapse to continue acting on post synaptic neurons
13
Q
Toxicity of SSRIs (4)
A
- Anxiety
- Weight loss/gain
- Headache, nausea
- Sexual dysfunction
- no fatality in overdose
14
Q
Toxicity of TCAs (4)
A
- Tachycardia, arryhthmias
- Postural hypotension
- Anti cholinergic effects - constipation, dry mouth, dry eyes, glaucoma, blurred vision
- CNS effects - sedation, fatigue
15
Q
Hypotheses of psychosis (2)
A
- Excessive dopamine in mesocortico-limbic system
2. Abnormality in 5-HT, glutamate & other systems
16
Q
Symptoms of schizophrenia
A
- type of psychosis
- Positive symptoms
- delusion (abnormal belief), hallucination, disorganised thinking, speech, behaviour - Negative symptoms
- avolition, affect flattening, inability to plan, poor concentration
- duration of disturbances - 6m
- deterioration in social/occupational function
- anti psychotics work better on positive symptoms
17
Q
Drugs used in psychoses
A
- Typical (first gen)
- Trifluoperazine
- Haloperidol
- Depot flupentixol - Atypical (second gen)
- Risperidone
- Olarizapine
- Quetiapine
- Clozapine
18
Q
Mechanism of action of antipsychotics
A
- blocks dopamine receptors in extrapyrimidal system, limbic midbrain, frontal cortex
- typical blocks D2 > 5HT2 receptors, atypical blocks 5HT2 > D2
- blocks D1, cholinergic, histaminic & alpha adrenergic
19
Q
Toxicity of typical antipsychotics (6)
A
- Extrapyrimidal effects
- Anti-adrenergic effects
- Anti-cholinergic effects
- Metabolic & endocrine effects
- Allergic effects
- others
20
Q
Toxicity of atypical antipsychotics (5)
A
- Agranulocytosis (2%) - clozapine
- Weight Gain - esp in clozapine, olanzapine
- Sedation - clozapine, olanzapine
- Extrapyrimidal (dose dep) - risperidone
- Metabolic syndrome - quetiapine
21
Q
Extrapyrimidal side effects (5)
A
- Acute Dystonia
- spasm of muscles of tongue, face, neck, back, extraocular - Parkinsonism
- bradykinesia, rigidity, tremor, mask facies - Akathisia
- irresistable urge to move about, physical restlessness - Malignant syndrome
- catatonia, stupor, fever, unstable blood pressure, myoglobinemia, can be fatal - Tardive dyskinesia
- oral-facial dyskinesia
- widespread chloreoathetosis
- abnormal movement of trunk, pelvis
