Psychopharmacology Flashcards
(44 cards)
what are the indications for use of Antidepressants?
Unipolar and bipolar depression, organic mood disorders, schizoaffective disorder, anxiety disorders including OCD, panic, social phobia, PTSD. There is a delay typically of 3-6 weeks after a therapeutic dose is achieved before symptoms improve.
list the types of Antidepressants…
Tricyclics (TCAs)
Monoamine Oxidase Inhibitors (MAOIs)
Selective Serotonin Reuptake Inhibitors (SSRIs)
Serotonin/Noradrenaline Reuptake Inhibitors (SNRIs)
Novel antidepressants
what are TCA’s side effects?
Very effective but potentially unacceptable side effect profile i.e. antihistaminic (weight gain, sedation), anticholinergic (dry mouth, dry eyes, constipation, memory deficits and potentially delirium), antiadrenergic (orthostatic hypotension, sedation, sexual dysfunction). QT lengthening, lethal in overdose (can overdose on a weeks supply)
what do tertiary TCA’s act on? Give egs ontertiary tca’s…
Act predominantly on serotonin receptors
Examples:Imipramine, amitriptyline, doxepin, clomipramine
what are secondary TCA’s and what do they act on, give egs too…
metabolites of tertaiary amines, Primarily block Noradrenaline. Eg’s: Desipramine, notrtriptyline
What are MAOI’s and list their side effects…
bind irreversibly to monoamine oxidase preventing amine inactivation leading to increased synaptic levels on amines. Side effects:orthostatic hypotension, weight gain, dry mouth, sedation, sexual dysfunction and sleep disturbance
when can a hypertensive crisis occur with MAOI’s?
when taken with tyramine-rich foods or sympathomimetics
when can a serotonin syndrome occur with MAOI’s?
If you take MAOI with meds that increase serotonin or have sympathomimetic actions. Serotonin syndrome sx include abdominal pain, diarrhea, sweats, tachycardia, HTN, myoclonus, irritability, delirium. Can lead to hyperpyrexia, cardiovascular shock and death. To avoid need to wait 2 weeks before switching from an SSRI to an MAOI.
what are SSRI’s and their side effects…
Block the presynaptic serotonin reuptake. Treat both anxiety and depressive sx, Most common side effects include GI upset, sexual dysfunction (30%+!), anxiety, restlessness, nervousness, insomnia, fatigue or sedation, dizziness
discontinuation syndrome…
condition that can occur following the interruption, reduction, or discontinuation of antidepressant medication. The symptoms may include flu-like symptoms, trouble sleeping, nausea, poor balance, sensory changes, and anxiety.
PROS and CONS of - Paroxetine
P - short half life, no build up, sedating properties (dose at night) gives relief from anxiety and insomnia. C - Sedating, wt gain, more anticholinergic effects Likely to cause a discontinuation syndrome
PROS and CONS of - Sertraline
P - weak P450 interactions, short half life, less sedating compared to paroxetine. C - max ab. Requires a full stomach, increase number of GI adr’s
PROS and CONS of - Fluoxetine (Prozac)
P - Long half-life so decreased incidence of discontinuation syndromes. Good for pts with medication noncompliance issues. Increased energy. C - long half life and active metabolite may build up (e.g. not a good choice in patients with hepatic illness), Significant P450 interactions so this may not be a good choice in pts already on a number of meds, more likely to unduce mania than other SSRI’s
PROS and CONS of - Citalopram
P - Low inhibition of P450 enzymes so fewer drug-drug interactions, Intermediate ½ life. C - Dose-dependent QT interval prolongation, can be sedating anf has GI side effects.
PROS and CONS of - Escitalopram
P - Low overall inhibition of P450s enzymes so fewer drug-drug interactions, Intermediate 1/2 life, more effective than citalopram in acute response and remission. C - Dose-dependent QT interval prolongation, nausea and headache.
PROS and CONS of - Fluvoxamine
P - shortest half life, analgesic properties. C - short half life, GI side effects, headaches, sedation, weakness, Strong inhibitor of CYP1A2 and CYP2C19
what are SNRI’s?
Inhibit both serotonin and noradrenergic reuptake like the TCAS but without the antihistamine, antiadrenergic or anticholinergic side effects. Used for depression, anxiety and possibly neuropathic pain
PROS and CONS of - Venlafaxine
minimal drug interactions, short half life and fast renal clearance avoids build up so good for the geriatric population. C - 10-15 mmHG dose dependent increase in diastolic BP, nausea, Can cause a bad discontinuation syndrome, QT prolongation, sexual side effects.
PROS and CONS of - Duloxetine
P - efficacy for physical sy of depression, less BP increase as compared to venlafaxine. C - Cannot break capsule, as active ingredient not stable within the stomach, higher drop out rate.
Novel Antidepressants: PROS and CONS of - Mirtazapine
P - good augmentation strategy. C - inreases serum cholestrol and TAG’s, sedating, weight gain association
Novel Antidepressants: PROS and CONS of - Buproprion
P - good augmentation strategy, Mechanism of action likely reuptake inhibition of dopamine and norepinephrine . C - siezure risk increased, abuse potential because can induce psychotic sx at high doses, anxiety, agitation and insomnia too.
CASE 1…
Susie has a nonpsychotic unipolar depression with no history of hypomania or mania. She has depressed mood, hyperphagia, psychomotor retardation and hypersomnolence. What agent would you like to use for her?
Establish dx: Major depressive disorder and target symptoms. For a treatment naive patient start with an SSRI.
Using the side effect profile as a guide select an SSRI that is less sedating. Good choices would be Citalopram, Fluoxetine or Sertraline.
CASE 2…
ob is a 55 year old diabetic man with mild HTN and painful diabetic neuropathy who has had previous depressive episodes and one suicide attempt. He meets criteria currently for a major depressive episode with some anxiety. He has been treated with paroxetine, sertraline and buproprion. His depression was improved slightly with each of these meds but never remitted.
Establish dx: Major depressive disorder with anxious features. Assuming he received adequate trials previously would move on to a duel reuptake inhibitor as he had not achieved remission with two SSRIS or a novel agent. Given his mild HTN would not choose Venlafaxine. TCA’s can help with neuropathic pain and depression however not a good choice given the SE profile and lethality in overdose. Duloxetine is a good choice since it has an indication for neuropathic pain, depression and anxiety. Three birds with one stone!! Keep in mind Duloxetine is a CYP2D6 and CPY1A2 inhibitor and has potential drug-drug interactions. Combination of antidepressants eg SSRI or SNRI with Mirtazepine. Adjunctive treatment with Lithium. even ECT if nothing else works.
what are indications of use of Mood Stabilisers?
Bipolar, cyclothymia, schizoaffective, Mania
