Drugs Used in Psychiatric Disorders Flashcards
How do psychiatric drugs work, generally speaking?
Agonists or antagonists of neurotransmitter receptors, or as an inhibitor of a regulatory enzyme
What are the 3 core symptoms of depression, and how many do you need to diagnose depression?
Low mood
Decreased energy
Anhedonia
What are the secondary symptoms of depression?
Decreased appetite, sleep disturbance, physical aches, irritability, self harm, suicidal thoughts, reduced concentration, as well as psychotic symptoms if severe, and reduced libido.
What class of neurotransmitter are NA and serotonin?
Monoamine neurotransmitters
What is the theory of pathophsiology of depression?
Deficiency of neurotransmitters such as NA and serotonin, or receptor abnormality. Depletion causes compensatory upregulation of post-synaptic receptors.
What are the classes of antidepressants?
TCAs SNRIs SSRIs MAOIs NARIs Other including mirtazepine
What is the indication for SSRIs?
moderate to severe depression, alongside CBT
Which SSRI is the most selective?
Citalopram
Which is the most potent SSRI?
Paroxetine
Tell me about the pharmacokinetics of SSRIs.
Almost complete absorption in the gut
Long half life (once daily dose)
Metabolised in the liver
Are SSRIs generally well tolerated?
Yes
What are the most common side effects of SSRIs?
Loss of appetite, nausea, and diarrhoea
What are some of the rarer side effects of SSRIs?
Precipitation of mania
Possible increased suicidal ideation
Neurological side effects
What neurological side effects do you get with SSRIs?
Extra-pyramidal i.e. parkinsonian
What is the risk of taking an overdose of SSRIs?
Not much of a risk, as long as taken alone
Which SSRIs cause QT prolongation?
Citalopram
What are the main TCAs?
Amitryptiline
Imipramine
Clomipramine
Lofepramine
How do SSRIs work?
Selective serotonin reuptake inhibitor - prevent serotonin reuptake so more is available in the synapse to keep receptors saturated.
How to TCAs work?
Inhibit NA reuptake, block muscarinic cholinergic receptors, and alpha 1 adrenoceptor blockage.
Tell me about the pharmacokinetics of TCAs.
Lipid soluble
Aborbed in the gut and metabolised by liver
Long half lives
What are the CNS side effects of TCAs?
Sedation
Impaired psychomotor skills
Seizure threshold lowered
What is the ANS and GI side effect of TCAs?
Reduced glandular secretions
Constipation
What are the CVS side effects of TCAs?
Tachycardia
Postural hypotension
Impaired myocardial contractility
If a pt already on NSAIDs is given an SSRI, what else should they be given, and why?
PPI as they are at an increased risk of developing a GI bleed
