Antidepressants (PSYCH DRUGS) Flashcards
First-line antidepressant
SSRI - selective serotonin receptor inhibitor (few SE because selective action on serotonin alone)
SSRI
1. Full name
2. MOA
Selective Serotonin Reuptake Inhibitor
- MOA: block serotonin reuptake by transmitting neurons -> elevated serotonin levels in synaptic space -> prolonged action on receiving neuron
SSRI side effects - common AND uncommon
Common
1. Anxiety
2. Insomnia
3. Headache
4. Nausea
5. Diarrhea
6. Sexual dysfunction
Uncommon
1. Antidepressant-induced hypoNa (common in old people, manifestations: lethargy, muscle ache, nausea, more severe- cardiac failure, confusion, seizure)
2. GI bleed/GI ulcer
3. Serotonin syndrome (applies to antidepressants as a class)
SSRI indications
- Depression with anxiety/obsessional symptoms
- Depression in elderly (due to benign SE profile)
- Suicidal pt (safe in OD)
- (conditions with serotonin deficiency) Panic disorder, social anxiety disorder, PTSD, OCD, bulimia nervosa
SSRI examples AND dose
x5
1. Fluoxetine (20 mg OM)
2. Fluvoxamine (50 mg OM to 50 mg BD)
3. Paroxetine (20mg OM)
4. Sertraline (50mg OM)
5. Escitalopram (10mg OM)
SNRI Full name + MOA
Serotonin noradrenaline reuptake inhibitor
MOA: dual action - block serotonin and noradrenaline reuptake transporters
SNRI side effects
Similar to SSRI PLUS adrenergic SE
- Anxiety
- Nausea
- # Sexual dysfunction
- Tachycardia, HTN, mydriasis, diaphoresis
- Dry mouth
- Constipation
SNRI example and dose
- Venlafaxine (75mg/day)
- Desvenlafaxine (50mg/day)
- Duloxetine (60mg/day)
SNRI indications
- Depression
- Generalised anxiety disorder
- Pain symptoms in depression
Duloxetine added benefits
Effect on pain symptoms in depression eg. Back ache
Which SNRI has Discontinuation symptom?
Venlafaxine
TCA MOA
MOA: dual action - block both serotonin and noradrenaline transporters PLUS block cholinergic, histamine, alpha-adrenergic receptor, sodium channel ***dirty drug!! broad spectrum
TCA side effect
- Dry mouth, tachycardia, memory impairment (bad for elderly), acute closed angle glaucoma [muscarinic M1 receptor blockade]
- Sedation, weight gain [block histamine receptor]
- Postural hypotension [block alpha adrenergic receptor]
- Arrythmia ***overdose + wide QRS complex = TCA OD seizure [block Na channel]
TCA efficacy, safety
Efficacy: superior to other antidepressants
Safety: highly lethal in OD (VF, seizure 2’ to Na channel blockade)
TCA indication
- Severe depression (superior to newer agents)
- Specific dx (chronic pain, fibromyalgia, migraine, insomnia) - use amitriptyline
- Specific dx (OCD) - use clomipramine
Avoid TCA in
- Elderly
- Physically ill
- The suicidal (if really need to prescribe, do safety advice - family keep drugs for pt)
TCA examples and dose
x4
1. Amitriptyline (25-150mg)
2. Imipramine (25-150mg)
3. Dothiepin (25-150mg)
4. Clomipramine (25-100mg)
Noradrenaline Dopamine Reuptake Inhibitor MOA
MOA: block both dopamine and noradrenaline reuptake transporters
Noradrenaline dopamine reuptake inhibitor example AND dose
Bupropion 150mg/day
Noradrenaline dopamine reuptake inhibitor/Bupropion Side effects
- Insomnia, agitation, anxiety (as a result of overstimulation ***rmb that bupropion can be used in ADHD!)
- Seizures (due to effects of elevated dopamine levels on seizure threshold)
Has NO effect on sexual dysfunction
Noradrenaline dopamine reuptake inhibitor Indications
- Depression with anhedonia
- Depression with fatigue
- Smoking cessation
- ADHD (child psych)
Avoid noradrenaline dopamine reuptake inhibitor (bupriopion) in
- Anxiety disorders
- Panic attacks
- Seizures
NaSSA full name + MOA
Noradrenergic and Specific serotonergic antidepressant **diff from SNRI (block reuptake transporter) VS NaSSA (block receptors)
MOA: x3
1. Block presynaptic alpha 2 receptors of noradrenergic AND serotonergic pathways (which are normally responsible for -ve feedback) -> increases noradrenergic and serotonergic neurotransmission
2. Block postsynaptic serotonin 5HT2 AND 5HT3 receptors
3. block histamine 1 receptor -> sedating effect