Anti-Depressants Flashcards
Two Primary Types of Depression Classification
Differentiation?
MDD or Unipolar
Bipolar - has manic episodes
Key is MANIC EPISODES
Chemical Anti-Depressant Important Considerations (3)
Ineffective in 30% of patient population
Therapeutic response takes weeks to months
Side effects can limit dosing - elderly are more likely to experience adverse effects
Two Hypotheses of Depression
Monoamine/Biogenic Amine
Neurotrophic
Monoamine/Biogenic Amine Hypothesis
Depression may be related to DEFICIENCY OF 5-HT, NE, and DA
Neurotrophic Hypothesis
Loss of NEUROTROPHIC GROWTH FACTORS
BDNF - “brain fertilizer”
MAOI Mechanism of Action
block MAO enzyme (MAO a or b)
increases synaptic availability of NE AND 5-HT
MAO-A targets
MAO-B targets
A - Tyramine, NE, 5-HT, DA
B - DA
Phenelzine
MAO-A and B inhibitor
irreversible
WORSE SIDE EFFECT PROFILE
Tranylcypromine
MAO-A and B inhibitor
Irreversible
WORSE SIDE EFFECT PROFILE
Selegiline
Dose dependent uses?
MAO-B Inhibitor (low dose)
Non-selective (High dose)
Low dose - Parkinsons
High dose - Antidepressant
MAOI Most common side effects
ORTHOSTATIC HYPOTENSION - alpha-1 receptor inhibition in brainstem
WEIGHT GAIN
Irreversible MAOi’s have HIGHEST RATE OF SEXUAL DYSFUNCTION
Food Interactions
Tyramine
HYPERTENSIVE CRISIS
Tricyclic Antidepressant Important clinical use
CHRONIC PAIN CONDITIONS
tricyclic - three ring structure
Tricyclic Antidepressant MOA
block reuptake of 5-HT AND NE
inhibits SERT and NET
Imipramine - drug type? MOA? Important characteristic?
inhibits SERT and NET
PROTOTYPE TCA
has some anti-cholinergic effect
Used to treat enuresis
Desipramine - drug type? MOA? Important characteristic?
TCA
inhibits SERT and NET
More effective at treating neuropathic pain
Amitriptyline - drug type? MOA? Important characteristic?
TCA
inhibits SERT and NET
Sedative effects
Side Effects of TCA’s
Hip breakers in elderly patients - ORTHOSTATIC HYPOTENSIONS
DELIRIUM in elderly more pronounced
CARDIAC TOXICITY
OVERDOSE - convulsions, coma, cardiac arrythmias
TCA Drug Interactions
Do not use with MAOI’S OR SSRI’S
6 Available SSRI’s
Fluoxetine Sertraline Paroxetine Citalopram Escitalopram Fluvoxamine
SSRI’s MOA
selectively inhibit SERT and block reuptake of 5-HT into presynaptic terminal
SSRI’s Side Effects
Short term - NAUSEA, GI UPSET, DIARRHEA
Long term - SEXUAL DYSFUNCTION
LOW RISK OF OVERDOSE
SSRI’s Drug Interaction
SEROTONIN SYNDROME if used with other anti-depressants
Serotonin Syndrome
Rare side effect d/t LONG HALF LIFE
Need to ALLOW TIME FOR DRUGS TO CLEAR BEFORE MAKING SWITCHES
Fluoxetine and Serotonin Syndrome avoidance
Discontinued for 4-5 WEEKS prior to using other anti-depressants
(others are 2 weeks)
Discontinuation Syndrome
discontinuation of SHORT HALF-LIFE SSRI’s
Dizziness, paresthesias, anxiety
only occurs in some patients
Venlafaxine - drug type? MOA?
Clinical?
SNRI
inhibit BOTH SERT AND NET
severe depression
Duloxetine - drug type? MOA?
Clinical?
SNRI
inhibits BOTH SERT AND NET
increasing use for CHRONIC PAIN
Trazodone - drug type? MOA?
Clinical?
Side effect?
Atypical anti-depressant
BLOCKS 5-HT2 AND H1
unlabeled hypnotic
Priapism - prolonged painful erections - peripheral alpha-1 block
Bupropion - drug type? MOA?
Clinical?
Atypical Antidepressant
BLOCKS NE AND DA REUPTAKE
SMOKING CESSATION
Mirtazapine - drug type? MOA?
atypical antidepressant
Blocks pre-synaptic alpha-2 - increases 5-HT and NE release
Anti-depressant Treatment Considerations
2-4 weeks for therapeutic effect
SHOULD NOT COMBINE DIFFERENT CLASSES
Pharmacokinetic Considerations
most INHIBIT CYP ISOENZYMES - 2D6 and 3A4
Never combine TCA’S AND SSRI’S –> SEROTONIN SYNDROME AND TCA TOXICITY
Bipolar Disorder Treatment
Main drug?
Drugs used to treat acute mania?
Lithium - mood stabilizing agent - MAINTENANCE
Valproic acid and Carbamazepine - anti-convulsants
Lithium Side Effects
Tremor
Hypothyroidism
Nephrogenic diabetes insipidus
Skin reactions
Lithium Drug Interactions
THIAZIDES AND LOOP DIURETICS
diminishes Li clearance - can cause toxicity
