What is cranial nerve V and it's branches and where does it leave to cranium?
Trigeminal branching into:
- V1 - Opthalmic nerve - Superior orbital fissure
- V2 - Maxillary nerve - Foramen rotundum
- V3 - Mandibular nerve - Forman ovale
What are the 3 main ionotropic receptors for glutamate and what are they permeable to?
- AMPA - Sodium
- NMDA - Calcium and Sodium
- Kainate - Sodium and Calcium
What are the 4 main SSRIs?
- Fluoxetine (Prozac)
What are the symptoms of serotonin syndrome?
How would a patient feel with a depersonalisation disorder?
- Feeling unreal
- Feel like a robot or an actor
Name 2 drugs that block dopamine receptors.
How does Mirtazapine produce an antidepressant effect?
It blocks the α2-adrenoreceptor on the presynaptic terminal
It also blocks the 5HT2 and 5HT3 receptors
This leads to an increase in synaptic serotonin
What are some agonists of the serotonin receptors?
- Sumatriptan - migraine treatment
What are the 3 main types of opioids found in the CNS?
What are the side effects of Trazodone?
- N & V
- Postural hypotension
What drugs do the TCAs interact with?
- Other sedatives; opioids, alcohol, anxiolytics and sedative antihistamines
- Drugs that prolong QT interval - Amiodarone
- Catecholamines and other sympathomimetics
- SSRIs - Increase plasma concentration of TCAs
What is cranial nerve II and where does it leave to cranium?
Optic nerve - Optic canal
Name 4 MAOI antidepressants.
- Phenelzine - irreversible
- Isocarboxazid - irreversible
- Tranylcypromine - irreversible
What is another use of the TCA amitripyline apart from depression?
The treatment of neuropathic pain.
What are the equivalent doses of Chlordiazepoxide, Lorazepam, Oxazepam, Nitrazepam and Temazepam to 5mg Diazepam?
- Chlordiazepoxide - 15mg
- Lorazepam - 500micrograms
- Oxazepam - 5mg
- Nitrazepam - 15mg
- Temazepam - 10mg
What is cranial nerve III and where does it leave to cranium?
Oculomotor nerve - Superior orbital fissure
Where is the 'vomiting centre' found and what does it detect in the blood?
The area postrema at the base of the 4th ventricle
It detects levels of serotonin
What are the somatic presentations of depression?
- Early morning waking
- Psychomotor retardation or agitation
- Weight loss
- Feel worse in the mornings
- Loss of emotional reactivity
What drugs interact with Venlafaxine?
What functions does dopamine have in the CNS?
What is cranial nerve IV and where does it leave to cranium?
Trochlear nerve - Superior orbital fissure
What is cranial nerve X and where does it leave to cranium?
Vagus nerve - Jugular foramen
Which dopamine pathway feeds into the limbic system?
What is cranial nerve VII and where does it leave to cranium?
Facial nerve - Internal acoustic meatus
What is tyrosine the precursor for?
What are the 2 subtypes of the monoamine oxidase enzyme and what do they do?
- MAO-A; preferentially degrades serotonin
- MAO-B; preferentially degrades phenylethamine and dopamine
What is the main inhibitory neurotransmitter of the CNS?
GABA - γ-Amino Butyric Acid
What is derealisation?
- Patient describes as unreal
- The surroundings lack colour or life
- Often described as "as if I were watching a film"
What is cranial nerve I and where does it leave the cranium?
Olfactory nerve - Cribiform plate
Which cells take up GABA and degraded it to glutamine?
What are the effects of a MAOI overdose?
- Hypotension - no dot use vasopressor drugs to fix - acute hypertensive crisis
- Hypertension - use phentolamine to correct
What are the symptoms of a severe depressive episode with psychotic symptoms?
- Delusions of sin, guilt, poverty or imminent disaster
- Hypochondriacal or nihilistic
- Auditory hallucinations of defamatory or accusatory nature
- Olfactory hallucinations of faeces or rotting flesh
- Severe retardation or stupor
What is the antidepressant of choice following a MI or in cardiac disease?
Which TCA has the lowest risk of fatality if taken in an overdose?
Which drugs target the serotonergic system?
- SSRI - Fluoxetine
- SNRI - Tramadol
- Ondansetron - anti-emetic drug
What are the 2 main SNRIs used for depression?
What are the main side effects of the MAOIs?
- Postural hypotension
- Atropine-like effects; not as severe as TCAs
- Weight gain
- CNS stimulation; insomnia, restlessness and hallucinations
Apart from the "cheese reaction", what other drugs interact with MAOIs?
- Opioids; particularly pethidine
- Ephedrine containing products
What is cranial nerve XII and where does it leave to cranium?
Hypoglossal nerve - Hypoglossal canal
What behaviours has serotonin been linked to?
What are the contra-indications for the use of TCAs?
- Narrow angle glaucoma
- Recent MI
- Heart block
What are the side effects of Mirtazapine?
- Increased appetite and weight gain
- Postural hypotension
- Sedation and drowsiness
- Sexual dysfunction in rare cases
Which drugs activate the GABAa receptor and what does this cause?
- Benzodiazapiens such as Lorazepam
They cause sedation of the individual.
What enzyme is involved in the conversion of glutamine/glutamate into GABA?
What are examples of hypnotic Benzodiazepines?
What does the syndrome of inappropriate antiduiretic hormone secretion (SIADH) produce?(Side effect of SSRI)
Which SSRI has an increased risk of insomnia and agitation?
Which SSRI is most likely to produce sedation and have discontinuation symptoms?
What are other common symptoms of depression?
- Reduced concentration and attention
- Reduced self-esteem and self-confidence
- Ideas of guilt and unworthiness
- Bleak or pessimistic views of the future
- Ideas of self harm/ suicide
- Disturbed sleep
- Diminished appetite
What are the side effects of Benzodiazepines?
- Drowsiness and falls
- Impairments in judgement and dexterity
- Forgetfulness, confusion, irritability, aggression and paradoxical dis-inhibition
- Dependance can develop
Which receptors does Trazodone block?
What drugs target noradrenaline receptors in the CNS?
What are the side effects of the SSRIs?
- GI distrubances
- GI bleeding
- Sexual dysfunction
- QT prolongation
- Serotonin syndrome
What are the withdrawal symptoms of Benzodiazepines?
- Loss of appetite and weight loss
Which hypnotic Benzodiazepine is associated with a "hangover effect", and why?
Nitrazepam - Longer acting benzodiazepine; still has affects in the morning after taking
What is the main difference between the 2 classes of GABA receptor (GABAa and GABAb)?
GABAa are ionotropic causing fast inhibition through Cl influx
GABAb are metabotropic and involved in presynaptic inhibition of neurotransmitter release from the presynaptic terminal
Which areas of the brain synthesise dopamine?
- Ventral midbrain
- Substaintia Nigra
- Ventral tegmental area
How do TCAs exert their effect?
They inhibit the reuptake of noradrenaline and serotonin
The compete for pre-synaptic receptors
Also bind to acetylcholine and histamine receptors.
What side effects are seen with Duloxetine?
- Increase in HR and BP
Why are SSRIs contra-indicated in under 18 year olds?
There is an increased risk of suicide and self harm in this age group.
What are the core symptoms of depression?
- Depressed mood
- Loss of interest
- Reduced energy
- Tiredness after minimal effort
- Usually at least 2 weeks in duration
Where is noradrenaline produced within the CNS?
- Locus coeruleus
- Nucleus of the Solitary Tract
What are some antagonists of the serotonin receptors?
- Clozapine - atypical antipsychotic
What are the 4 main classes of antidepressants?
What is cranial nerve VIII and where does it leave to cranium?
Vestibulocochlear nerve - Internal acoustic meatus
Where is the majority of serotonin found in the body?
The GIT - The enterochromaffin cells
Where are opioids projected to in the CNS?
- Periaqueductal Grey
What type of receptor does Noradrenaline bind to in the CNS?
Which SSRI has a long half-life, so can be stopped abruptly if needs be?
Above what doses does Venlafaxine produces its greatest efficacy?
What functions is acetylcholine linked to?
- Acetylcholine from basal forebrain; memory and cognition
- From the tegmentum; arousal and sleep.
When are MAOIs likely to be given?
They are given if other first line drugs do not work.
Where in the CNS is acetylcholine produced?
- Basal forebrain
- All motor neurones
What are the adverse effects of TCAs and how long do they usually last?
- Motor in-coordination
- Weight gain
- Usually last 1-2 weeks and stop as the antidepressant effect starts
What are the side effects of Venlafaxine?
- Sexual dysfunction
- Weight changes
- Increased BP in higher doses
What is the main excitatory neurotransmitter of the CNS?
What is the other main inhibitory neurotransmitter apart from GABA, and where is mainly localised?
Mainly found in the brainstem and spinal cord
What happens to glutamate receptors when alcohol or ketamine is ingested?
They are blocked leading to sedation of the individual
What is cranial nerve VI and where does it leave to cranium?
Abducent nerve - Superior orbital fissure
What is quorum sensing?
It is the use of chemicals, such as serotonin, by bacteria to detect the number of similar pathogens in the area
Used by Entamoeba histolytica
What is cranial nerve XI and where does it leave to cranium?
Accessory nerve - Jugular foramen
Where is histamine produced in the CNS?
Which dopamine pathway activates the striatum?
The mesostriatal pathway
What are the different severities of depression?
- Mild - 2 Core symptoms plus 2 others
- Moderate - 2 core symptoms plus 3/4 others
- Severe - Core symptoms plus 4 others that are intense
Which drug classes are more cardiotoxic, TCAs or Mirtazapine?
What is the "wash-out" period?
- It is the period needed for MAOI to leave the body
- It is usually 2 weeks and no new antidepressants should be given
Name some TCAs that are more selective for the prevention of noradrenaline reuptake?
What the is "cheese reaction"?
It is the interaction of MAOIs with tyroamine rich food such as mature cheese, beer, yeast extract and pickled herring
It is characterised by severe hypertension
What should be avoided if taking Trazodone?
- Other antidepressants
What are opioids involved with in the CNS?
What is cranial nerve IX and where does it leave to cranium?
Glossopharyngeal nerve - Jugular foramen
What is noradrenaline involved with in the CNS?
What are the 2 main receptors for dopamine and what is their action?
- D1 - excitatory
- D2 - inhibitory
What side effects of TCAs are related to the blocking of α1-adrenoreceptors?
- Postural hypotension
- Tachycardia; ventricular dysrhythmias and QT prolongation
What are the 2 main non-specific TCAs?
Which SSRIs increase the plasma concentrations of antipsychotics and TCAs?
What is the street name of Flunitrazepam?
Rohypnol or roofies
What drugs do the SSRIs interact with?
Which antidepressant is associated with the greatest risk of death from an overdose?
What Parkinson's treatment increases the level of dopamine available?
What are the anti-muscarinic side effects of TCAs?
- Blurred vision
- Dry mouth
- Urinary retention
- Also termed Atropine-like side effects.
Where is serotonin produced within the CNS?
The raphe nuclei in the brainstem.
Name some examples of anxiolytic Benzodiazepines.