Antidepressants Flashcards
What are antidepressants used to treat?
Affective Disorders
What are the affective disorders antidepressants treat?
Depressed mood and anhedonia (inability to experience pleasure)
Sleep disturbances
Feelings of hopelessness
Poor concentration
Suicidal tendencies
Biogenic Amine Theory of Affective Disorders
- hypothesis
Major depressive disorders (MDD) arise from a functional deficiency in the biogenic amines (serotonin, 5-HT; norepinephrine, NE or DA) in the CNS, while mania results from a functional excess
Biogenic Amine Theory of Affective Disorders
- Mechanism
TCAs and SSRIs block the re-uptake of biogenic amines at adrenergic and serotonergic nerve terminals
MAOIs prevents degradation of these NTs
How long does it take for TCAs and SSRIs to take effect?
2-4 weeks
Tricycle antidepressants (TCA)
Primarily inhibit NE and 5-HT reuptake at adrenergic and/or serotonergic nerve terminals
Anticholinergic side effects
Anticholinergic side effects
Dry mouth
Blurred vision (cycloplegia)
GI upset
TCA
- Types
Amitriptyline
Imipramine
Amitriptyline
Used to treat patients with neuropathic pain
Amitriptyline
- active metabolite
Nortiptyline
Imipramine
Used clinically to treat enuresis (bed wetting)
Imipramine
- active metabolite
Desipramine
Selective serotonin reuptake inhibitors (SSRIs)
Increase 5-HT levels by inhibiting its re-uptake in the neuronal synapse
Fewer anticholinergic side effects, less sedation, and orthostatic hypotension
SSRIs
- Types
Fluoxetine (Prozac)
Paroxetine
Sertraline (Zoloft)
Escitalopram
Monoamine oxidase inhibitors
- Types
Phenelzine
Tranylcypromine
Selegiline
MOI
- Phenelzine
Irreversible inhibitor of MAO-A and MAO-B
MOI
- Tranylcypromine
Irreversible inhibitor of MAO-A and MAO-B
MOI
- Selegiline
MAO-B selective inhibitor increases DA in synapse; used as an adjunct with L-DOPA to treat Parkinson’s Disease
Selegiline
- Main use
Helpful in PD
Used in adjunct to L-Dopa
Atypical Antidepressant Drugs
- Types
Bupropion
Venlafaxine
Duloxetine
Atypical Antidepressant Drugs
- Burproprion
DA and NE uptake blocker
Atypical Antidepressant Drugs
- Venlafaxine and Duloxetine
SNRI- 5-HT and NE re-uptake blockade
Side Effects - TCAs
- Antagonist actions at
H1 receptors
Muscarinic receptors
Alpha1-adrenoceptors
H1 antagonist
Sedation
Muscarinic antagonist
Atropine-like effects (dry mouth, blurred vision, cycloplegia, constipation, urinary retention)
Alpha1 adrenoceptor antagonist
Orthostatic hypotension
Tachycardia (problematic in elderly patients)
CNS toxicity
Delirium
Confusion
Cardiac toxicity (in overdose)
Na+ and Ca++ channel blockers
QT prolongation
Sweating
Myoclonus
Muscle twitching (sign of toxicity)
Weight gain
Major compliance issue
Side Effects- MAOIs
Hypertensive Crisis
Serotonin Syndrome
CNS SE
Anticholinergic effects and orthostatsis
Sexual dysfunction
Wt gain (not with selegiline)
Side Effects- MAOIs
- Hypertensive Crisis
Patients should be put on tyramine-restricted diets
Side Effects- MAOIs
- HTN Crisis TX
Hydralazine
Labetalol
Side Effects- MAOIs
- Serotonin Syndrome
High fever
Chills
Diarrhea
Agitation
Motor dysfunction (myoclonus, tremor, ataxia and weakness)
Side Effects- MAOIs
- Serotonin Syndrome TX
Ice packs
Cyproheptadine (serotonin block)
Side Effects- MAOIs
- CNS SE
Headache
Insomnia
Atypical SE
Bupropion
Atypical SE
- Bupropion
May induce seizures
Dry mouth
Insomnia
Wt loss
Atypical SE
- Bupropion TX
Lowers seizure threshold
All antidepressants can cause
Sexual dysfxn
- inhibited ejaculation in men and impaired orgasm in women
Boxed warnings of antidepressants
Antidepressants increase risk of suicidal thinking and behavior in children, adolescents and young adults
