Pharmacology of depression Flashcards
What are the core drugs used to treat depression?
Sertraline
Citalopram
Fluoxetine
Venlafaxine
Mirtazapine
What is the primary mechanism of action of Sertaline?
Inhibition of serotonin reuptake results in an accumulation of serotonin. Serotonin in the central nervous system plays a role in the regulation of mood, personality, and wakefulness.
What is the drug target of Sertraline?
Serotonin transporter
What are the main side effects of Sertraline?
GI effects (nausea, diarrhoea), sexual dysfunction, anxiety, insomnia
What affect can Sertraline have on dopamine levels?
Mild inhibition of dopamine transporter
Why is it important to monitor the dosage of Sertraline?
Must be gradually decreased on discontinuation. Partial inhibition of CYP2D6 at high doses (150 mg)- CYP2D6 inhibitors can decrease efficacy of many drugs as the CYP2D6 enzyme is involved in the metabolism of many drugs
What is the primary mechanism of action of Citalopram?
Inhibition of serotonin reuptake results in an accumulation of serotonin. Serotonin in the central nervous system plays a role in the regulation of mood, personality, and wakefulness.
What is the drug target of Citalopram?
Serotonin transporter
What are the main side effects of Citalopram?
GI effects (nausea, diarrhoea), sexual dysfunction, anxiety, insomnia
What affect can Citalopram have on other parts of the body?
Mild antagonism of muscarinic and histamine (H1) receptors
Why does the dose of Citalopram need to be monitored?
Must be gradually decreased on discontinuation. Metabolized by CYP2C19.
What is the primary mechanism of action of Fluoxetine?
Inhibition of serotonin reuptake results in an accumulation of serotonin. Serotonin in the central nervous system plays a role in the regulation of mood, personality, and wakefulness.
What is the drug target of Fluoxetine
Serotonin transporter
What are the main side effects of Fluoxetine
GI effects (nausea, diarrhoea), sexual dysfunction, anxiety, insomnia
What affect can Fluoxetine have on the rest of the body?
Mild antagonism of 5HT2A and 5HT2C receptors
Complete inhibition of CYP2D6 and significant inhibition of CYP2C19 (caution with warfarin).
What is the primary mechanism of action of Venlafaxine
Venlafaxine is a more potent inhibitor of serotonin reuptake than norepinephrine reuptake.
Noradrenaline in the central nervous system is implicated in the regulation of emotions and cognition.
What is the drug target of Venlafaxine?
Serotonin transporter
Noradrenaline transporter
What are the main side effects of Venlafaxine
GI effects (nausea, diarrhoea), sexual dysfunction, anxiety, insomnia, hypertension (at higher doses)
What is important to consider during the discontinuation of Venlafaxine?
Must be gradually decreased on discontinuation- wash out the drug before prescribing a new one to avoid drug-drug interactions (v. dangerous)
What is the primary mechanism of action for Mirtazapine?
Antagonises central presynaptic alpha-2-adrenergic receptors, which causes an increased release of serotonin and norepinephrine.
Antagonises central 5HT2 receptors, which leaves 5HT1 receptors unopposed causing anti-depressant effects.
What are the drug targets of Mirtazapine?
Alpha-2 receptor
5-HT2 receptor
What are the main side effects of Mirtazapine
Weight gain, sedation,
Less common: May exacerbate REM sleep behaviour disorder
Low probability of sexual dysfunction
Why is it important that many of the anti-depressant drugs are gradually decreased on discontinuation
- Have to be decreased/ discontinued before prescribing a new drugs: need to do a wash out to avoid drug- drug interference (can be v. dangerous)
- Gradually: body becomes used to/ dependent on the old drug/ effects of the old- needs to be washed out to avoid side effects
What are “the seven steps” for prescribing drugs to patients?
- Identify the patient’s problem
- Specify the therapeutic objective
- Select a drug on the basis of comparative efficacy, safety, cost and suitability
- Discuss choice of medication with patient (and carer) and make a shared decision about treatment
- Write a correct prescription
- Counsel the patient on appropriate use of the medicine
- Make appropriate arrangements for follow up (Monitor/stop the treatment)
