Depression Flashcards
What is the PHQ-9?
a nine item questionnaire designed to screen for depression in primary care
What questionnaire can we use in a primary care setting to diagnose depression?
Patient Health Questionnaire 9 (PHQ-9)
How can do we score the PHQ-9? What do the numbers mean?
What are the 3 most common prescribed SSRIs?
Sertraline
Citalopram
Fluoxetine
What are SSRIs?
selective serotonin reuptake inhibitors
What is the mechanism of action of SSRIs?
(target, location, effect)
Target: 5HTT
Location: pre-synaptic neurone
Effect: increased serotonin availability
What is the role of 5HTT?
transports the neurotransmitter serotonin from synapses to presynaptic neurons (reuptake of serotonin)
What change in an ECG might you see after someone starting taking citalopram?
prolonged QT interval
What factors may predispose someone to QT interval prolongation? (4)
increasing age
female sex
cardiac disease
hypokalaemia
What antibiotic may cause QR interval prolongation?
erythromycin
What can QT interval prolongation lead to?
Torsades de pointes
How does Torsades de pointes come about?
If you have a Long QT interval and your ventricles get an extra contraction during the time when they’re supposed to be getting ready for the next one, you may get Torsades de Pointes.
What 2 transporters does Venlafaxine target?
serotonin transporter
noradrenaline transporter
What 4 receptors does Mirtazapine target?
Histamine H1 receptor
Alpha-2 receptor
5HT2 receptor
HT3 receptor
What 4 receptors does Mirtazapine target?
Histamine H1 receptor
Alpha-2 receptor
5HT2 receptor
HT3 receptor
Why should you not prescribe Venlafaxine when a patient has hypertension?
Venlafaxine targets and inhibits the noradrenaline receptor and therefore has an adrenergic effect.
This can cause hypertension
Why may Mirtazapine help those who have trouble sleeping?
has a beneficial impact on sleep continuity and duration due to its anti-histaminergic effects.
Explain the selectivity, affinity and efficacy of Mirtazapine.
not high selectivity!
mirtazapine has very high affinity to histamine receptor
high efficacy for a-2-receptor and 5HT2 receptor for anti-depression effect
Potency vs efficacy of drugs?
Potency is the amount of drug necessary to produce a biological response of a certain magnitude.
Efficacy is the ability of the drug to produce a response by the activation of the receptor.
Affinity vs efficacy of drugs?
Affinity describes strength of drug binding with receptor (“fit the lock”).
Efficacy describes ability of drug-bound receptor to produce a response
Selectivity vs specificity of drugs?
Selectivity is the degree to which a drug acts on a given site relative to other sites.
Specificity is the measure of a receptors ability to respond to a single ligand
Explain selectivity and give an example of how a non-selective drug by act.
Selectivity is the degree to which a drug acts on a given site relative to other sites.
Relatively nonselective drugs affect many different tissues or organs. For example, atropine, a drug given to relax muscles in the digestive tract, may also relax muscles in the eyes and in the respiratory tract.
Explain specificity and give an example of how a non-specific drug by act.
Specificity is the measure of a receptors ability to respond to a single ligand.
Low specificity generally results in physiological responses not targeted or intended. (side effects of different effect of what the drug is meant to do)
