Pharmacology Flashcards
What does Monoamine Oxidase do?
Breaks 5-HT down into its inactive products, once it has re entered the pre synaptic bulb.
What do most Anti Depressants do?
Increase the concentration of serotonin in the synaptic cleft.
What is the precursor for 5HT?
Trytophan
Examples of Monoamine Oxidase inhibitors
Phenelzine
Moclobemide
Examples of monoamine neurotransmitters
Dopamine
Noradrenaline
5HT
Irreversible Monoamine Oxidase Inhibitors
Phenelzine
Reversible Monoamine Oxidase Inhibitors
Moclobemide
What severe side effect is linked to Monoamine Oxidase Inhibitors?
Cheese reaction
Dietary tyramine is not broken down leading to a hypertensive crisis.
What common side effect are linked to Monoamine Oxidase Inhibitors?
Insomnia
Postural hypertension
Peripheral oedema
How do Tricyclics work?
Block reuptake channels for 5-HT and Noradrenaline
Examples of Tricyclic antidepressants.
Imipramine
Amitriptyline
Tricyclic antidepressants have no Anticholinergic effects.
T/F
False they have a strong anticholinergic effect
What are some of the anticholinergic side effects of Tricyclic drugs?
Blurred Vision
Dry mouth
Constipation
Urinary retention
List some common side effects of Tricyclic antidepressants.
Sedation Weight gain postural hypertension tachycardia Arrhythmias
Why should Tricyclics never be prescribed for anyone with arrhythmias?
They are Cardiotoxic
Prolong QT
How do SSRIs work?
Selective Seretonin Reuptake Inhibitors
Block serotonin channels
Examples of SSRIs
Fluoxetine
Citalopram
Setraline
Give some common side effects of SSRIs
Nausea Headache Worsened anxiety Sweating Sexual dysfunction Hyponatraemia - elderly
SSRIs should be used in patients with a history of self harm. T/F
False
Be careful as SSRIs linked to transient increase in Self Harm
Side effects of SSRIs discontinuation
Flu like symptoms
Insomnia
N+V
How do SNRIs work?
Seretonin Norepinephrine re-uptake inhibotors
Noradrenaline and 5HT channels are blocked
Examples of SNRIs
Venlafaxine
Dulaxetine
Side effects of SNRIs
Similar to SSRIs
Less Anticholinergic side effects
A Tetracyclic Antidepressant selective for α2 5-HT2 and 5-HT3 reuptake channels.
Mirtazapine
Which side effects of Mirtazapine is actually a desirable one which advocates for its use?
Sedative
Use in patients who are suffering from insomnia or poor sleep.
Weight gain
Use in patients who are underweight
Some side effect so Mirtazapine.
Dry mouth
Increased appetite
List of Antidepressant Drugs
TCA MAOI SSRIs SNRIs Mirtazapine
What is the most common mood stabilising drug?
Lithium Carbonate
Side effects of Lithium
Dry mouth Polyuria Tremor Hypothyroidism Nephrogenic Diabetes Insipidus Weight gain
What are some signs a patient has toxic Lithium poisoning?
Diarrhoea Vomiting Ataxia Drowsiness Convulsiona Coma
List some common Anticonvulsants
Valproic acid
Lamotrigine
Carbamazepine
List some Antipsychotic drugs
Olanzapine
Aripiprazole
Quetiapine
What is the mode of action in Antipsychotic drugs?
Dopamine and 5 HT2 seretonin receptor antagonists
Some common side effects of Antipsychotic drugs.
Sedation
Weight gain
Metabolic syndrome
Extra pyramidal effects
What are the dopamine pathways within the Brain?
Mesolimbic Mesocortical Nigrostriatal Tuberoinfundibular Hypothalamospinal
Where does the mesolimbic pathway originate and terminate?
Ventral Tagmatic area to the limbic region
What does the mesolimbic pathway control?
Memory
Emotional control
Personality
Damage or dysfunction in the mesolimbic pathway results in what?
Delusions
Hallucinations
Thought insertion
What does the mesocortical pathway control?
Higher brain function
What does the Nigrostriatal pathway control?
Voluntary movement
Damage of dysfunction in the nigrostriatal pathway results in what?
Parkinsonism - tremor bradykinesia rigidity
Where is the tuberoinfundibulnar pathway found?
Around the pituitary gland
What are the main dopamine receptors?
D1-D5
Where would you find D1-D2 receptors?
Limbic and striatal areas
Which receptor is found most commonly in the mesolimbic pathway?
D2
List some D2 receptor antagonists
Raclopride
Haloperidol
Give an example of D4 receptor agonists
Clozapine
What do D2 receptors do when activated ?
Inhibit adenyl cyclase
Inhibit voltage gated Ca2+ channels
Open K+ channels
Hyperpolarise
What do D1 receptors do when activated ?
Stimulate cAMP
How does GABA affect the post synaptic membrane?
Inhibits neuronal activity by activating Cl- channels causing hyperpolarisation.
How do Benzodiazepines work?
Enhance the affect if GABA increasing the inhibition of postsynaptic potential
Describe the efficacy of Benzodiazepines?
Rapid action
Well tolerated for less than two weeks
What are the issues of Benzodiazepines?
Sedation Psychomotor impairment Withdrawal issues Dependancy and abuse Alcohol interactions- both act on same receptor Can worsen co-morbid depressions
What drugs are used in the treatment of anxiety?
Benzodiazepines Antidepressant drugs Buspirone Pregablin Beta Blockers Propanolol
What pathway is involved in anxiety?
Corticostriatal thalamic cortical circuit
What are the main neurotransmitters in the amygdala centred circuit?
5 HT GABA Glutamate CRF - Corticotrophin releasing factor Norepinephrine
What is the affect of GABA on anxiety?
Reduces affect of neurones in Amygdala and Corticostriatal thalamic cortical circuit
reduces anxiety
How do BDZ work to reduce anxiety?
BDZ enhance the action of GABA hence increasing suppression of amygdala and CTCC
How many types of GABA receptors are there?
A
B
C
GABA A is bound by what?
BDZ
Barbiturates
Alcohol
Activation of GABA A receptors does what?
Hyperpolarises the membrane by opening Cl- channels alowing influx of Cl- ions.
What properties do Ethanol, Neurosteroids and Barbiturates display?
Anxiolytic - reduce anxiety
Give a example of an Inverse BD2 agonist
B-Carboline
What properties do Inverse BD2 agonists displays i.e B-Carboline
Anxiogenic - Increase anxiety
What GABA antagonists are used in the treatment of BDZ overdose?
Flumazenil - Bind and block GABA A receptors
Give examples of Benzodiazepines.
Lorazepam
Diazepam
Chlordiazepam
What is Xanax?
Alprazolam - form of BDZ
What effect do BDZ have?
Reduce anxiety and aggression
Hypnosis and sedation
Muscle relaxent
Anticonvulsant effect
What are some clinical uses of BDZ?
Acute anxiety Hypnosis Alcohol withdrawal Mania Delirium Rapid tranquillisation Status Epilepticus
Why is a BDZ “fairly safe”?
As it is unlikely to cause respiratory depression
What are some issues surrounding the use of BDZ?
Some have paradoxical aggression
Anterograde amnesia
Impaired coordinations
Tolerance and dependance are risks
What some side effects of BDZ withdrawal?
Abdo cramps, Increased anxiety and panic attacks, Blurredvision
Muscle tension, chest pain, palpitation, sweating
Depression insomnia nightmares dizziness
N+V restlessness
What causes the withdrawal symptoms from BDZ?
Chronic BDZ used reduces GABA receptors response to GABA.
Less inhibitory input, as less GABA and less receptive to its presence.
What are some signs of rapid BDZ withdrawal?
Confusion Psychosis Convulsions Tachychardia Hypertension Agitation Tremor
How do you withdraw somoene from BDZ?
Transfer over to Diazepam or Chlordiazepam - taken at night
Reduce dose every 2-3 weeks - 2- 2.5 mg
Time needed varies from around 4 weeks to 1 year
If whilst withdrawing your patient from BDZ they start to develop symptoms what do you do?
Maintain dosage
What does seretonin do within the amygdala?
Innervates it
How do SSRIs and SRNIs increase extracellular seretonin?
Blockage of the Serotonin reuptake transporters
How does SSRI and SRNI usage help to reduce anxiety
After chronic usage due to increased extracellular Serotonin expression of serotonin and glucocorticoid receptors is decreased - less stimulation
What can SSRIs be used for, anxiety and fear?
Panic disorders OCD PTSD Phobias GAD
What SSRIs can be used, Anxiety?
Escitalopram
Paroxetine
Fluoxetine
What can Tricyclics be used for, anxiety and fear?
OCD
Panic disorder 2nd line
What Tricyclic are used, anxiety.
Clomipramine
Imipramine
What are SNRIs used for? Anxiety disorders.
GAD
What SRNI is sued in GAD?
Venlafaxine
What are MAOI used for? Anxiety disorder.
Social Anxiety disorders
What MAOI is use for social anxiety disorders?
Moclobemide
What is Pregablins mode of action?
GABA enhancer and Ca2+ channel blocker
When is Pregablin used in anxiety?
Only for unresponsive disease