Slides of a topic Antidepressants_Psychiatry.pdf

lecture note

1. Antidepressants
Psychopharmacology
With Helen M. Farrell, M.D.

2. Learning Objectives
•You will be able to identify the major classes of
medications.
•You will know about antidepressants, mood
stabilizers, antipsychotics and benzodiazepine
•You will be able to determine which patients are
best treated by what method.
•You will know the side effects of medication
classes.

3. Types of Antidepressants
Tricyclic antidepressants
(TCAs)
Monoamine oxidase
inhibitors (MAOIs)
Selective serotonin
reuptake inhibitors (SSRIs)
Atypical antidepressants
Types

4. Tricyclic Antidepressants Types
Drug examples
•Imipramine
•Amitriptyline
•Doxepin
•Clomipramine
•Nortriptyline
•Desipramine
Mechanism of action (MOA)
Blocks reuptake of
noradrenaline and serotonin
Use
•Major depression
•Enuresis
•OCD
•Fibromyalgia
Side effects
Anticholinergic
(tachycardia, urinary retention)
Anti alpha adrenergic
Sedation
Lower seizure threshold
Toxicity/side effects
•Can be fatal
•3 C's
•Convulsions
•Coma
•Cardiotoxicity
(arrhythmia)

5. Inhibit the reuptake of norepinephrine and serotonin, increasing availability in the synapse.
Mechanism of Action of Tricyclic Antidepressants (TCAs) Management

6. Rarely first line agents due to potential for toxicity and
lethality by cardiac arrhythmia in overdose.
Tricyclic Antidepressants (TCAs)
High-yield
Management

7. TCAs start on low doses to allow acclimation to the
common early anticholinergic side effects before
achieving therapeutic doses.
Tricyclic Antidepressants (TCAs)
Clinical pearl
Signs/Symptoms

8. •Sedation
•Orthostatic hypotension
•Tachycardia
•Arrhythmias
•Dry mouth
•Constipation
What are some of TCA Side Effects? Signs/Symptoms

9. •Urinary retention
•Blurred vision
•Weight gain
•Lethal in overdose (must assess suicide
risk as one-week supply can kill)
What are some of TCA Side Effects? Signs/Symptoms

10. The reason there are potentially so many side effects with
TCAs is that they have antihistamine, antiadrenergic,
antimuscarinicproperties therefore, they lack specificity.
Tricyclic Antidepressants (TCAs)
High-yield
Signs/Symptoms

11. MAOIs Types
Drug examples
•Phenelzine
•Tranycypramine
•Isocarboxazid
•Selegeline
Mechanism of action (MOA)
Decreased MAO activity results in decrease
amine degradation and increases levels of
amine neurotransmitters.
Use
•Atypical depression
•Treatment-resistant depression
•Anxiety
•Hypochondriasis
Side effects
•Hypertensive crisis
•CNS stimulation

12. •Prevent the inactivation of biogenic amines such as norepinephrine, serotonin, dopamine
and tyramine.
•MAO-A preferentially deactivates serotonin and MAO-B preferentially deactivates
norepinephrine and epinephrine
•Both types act on dopamine and tyramine.
Mechanism of Action of MonamineOxidase Inhibitors (MOIs)Management

13. Very effective for refractory depression.
MAOIs Indication Management

14. MAOIs are not first-line because of increased safety and
tolerability of other agents.
MAOIs
Clinical pearl
Signs/Symptoms

15. MAOI Side Effects
Sleep dysfunction
Dry mouth
Sexual dysfunctionOrthostatic hypotension
Drowsiness
Weight gain
Complications

16. Hypertensive crisis is a potentially deadly side effect.
Hypertensive Crisis
High-yield
Complications

17. The hypertensive crisis risk elevates when MAOIs are
taken with tyramine-rich food or sympathomimetics
foods with tyramine (Chianti wine, cheese, chicken liver,
fava beans, cured meats).
MAOIs
High-yield
Complications

18. The hypertensive crisis associated with MAOIs comes
from tyramine (found in wine and cheese). MAO usually
degrades tyramine but when it is inhibited it is fully
absorbed and displaces catecholamines.
MAOIs
Clinical pearl

19. The treatment for serotonin syndrome is
cyproheptadineand discontinuation of the offending
agent.
MAOIs
Clinical pearl
Management

20. SSRI Types
Drug examples
•Citalopram
•Escitlaopram
•Fluoxetine
•Fluvoxamine
•Paroxetine
•Sertraline
Mechanism of action (MOA)
Decreases the serotonin reuptake
pump in presynaptic neurons thereby
increasing synaptic serotonin
Use
•Depression
•OCD
•PTSD
•Panic
•Generalized anxiety
•Bulimia
•Binge eating
•Social phobia
Toxicity/side effects
•Very mild
•Weight gain
•QTC prolongation
•GI distress
•Sexual dysfunction
•Serotonin syndrome
•SSRI discontinuation
syndrome

21. Inhibit presynaptic serotonin pumps, leading to increased availability of serotonin
in synaptic clefts.
Selective Serotonin Reuptake Inhibitors (SSRIs) Management

22. SSRIs all have similar efficacy and side effects despite
structural differences.
SSRI Side Effects
High-yield
Signs/Symptoms

23. Low incidence of side
effects
Much safer in overdoseNo food restrictions
What Are SSRIs Several Distinct Advantages?
Clinical pearl
Management

24. Anxiety Depression OCD Premenstrual
dysphoric
disorder
Indications of SSRIs Signs/Symptoms

25. SSRI Side effects
Serotonin syndrome
Anorexia, weight loss
HeadacheSexual dysfunction
GI disturbance
Insomnia
Signs/Symptoms

26. Treat sexual side effects from SSRIs with bupropion or
mirtazapine.
SSRI
Clinical pearl
Management

27. SNRI Types
Drug examples
•Venlafaxine
•Duloxetine
Mechanism of action (MOA)
Increases serotonin,
noradrenaline and dopamine
Use
•Depression
•Fibromyalgia
•Generalized anxiety
•Diabetic peripheral
neuropathy
Toxicity/side effects
•Hypertension
•Sedation
•Nausea

28. SNRI Side Effects
Serotonin syndrome and
Hypertension
Anorexia, weight loss
HeadacheSexual dysfunction
GI disturbance
Insomnia
High-yield
Signs/Symptoms

29. Potential withdrawal from SNRIs can be seen after 13
missed doses (flulike symptoms and electric-like shocks
or zaps).
Withdrawal from SNRIs
High-yield
Complications

30. Atypical Antidepressants Types
Bupropion
Increases noradrenaline and
dopamine leading to a
stimulant effect
Mirtazapine
Alpha 2 antagonist that can
cause weight gain and
sedation

31. Serotonin Modulators Types
Trazodone
Inhibits serotonin reuptake
and causes sedation

32. Trazodone can cause priapism (sometimes called
trazobone).
Serotonin Modulators
Clinical pearl

33. Because of their safety and tolerability, SSRIs and atypical
antidepressants have become the most common agents
used to treat major depression.
Treating Major Depression
High-yield
Management

34. •Symptoms
•Risk of suicide
•Previous response to medications
(by patient or family)
•Side effects
•Comorbid conditions
Treatment Choice Should be Based on Diagnosis
Disease
Disease Disease

35. Indications for Antidepressants Other than Depression Diagnosis
Obsessive-compulsive
disorder
Panic disorder
Eating disorder
Dysthymia
Social phobia
Posttraumatic disorder
Irritable bowel syndrome
Enuresis
Neuropathic pain
Migraine headaches
Smoking cessation
Autism
Premenstrual dysphoric
disorder
Depressive phase of
manic depression
Insomnia

36. A group of symptoms that may occur from any SSRIs or
combination of MAOIs with SSRIs or SNRIs.
Serotonin Syndrome
High-yield
Definition

37. Serotonin Syndrome
Diarrhea
Dilated pupils
SweatingHigh body temperature
Agitation
Increased reflexes and tremors
Signs/Symptoms

38. Often occurs when SSRIs and MAOIs are taken together.
When does Serotonin Syndrome Occur? Definition

39. Lethargy
Assessment Serotonin InitialPhase
A.
B.
C.
D.
E.
Diagnosis
F.
B.Restlessness
C.Confusion
D.Flushing
E.Diaphoresis
F.Tremor and myoclonic jerks

40. Hyperthermia
Serotonin Syndrome Symptoms May Progress to
A.
B.
C.
D.
E.
Diagnosis
F.
B.Hypertonicity
C.Rhabdomyolysis
D.Renal failure
E.Convulsions
F.Coma and death

41. Always wait at least 2 weeks before switching from SSRI
to MAOI to avoid serotonin syndrome (5 weeks if
switching from fluoxetine to an MAOI).
Complications when Transitioning from SSRI to MAOI
Clinical pearl
Complications

42. Bupropion (Wellbutrin)
commonly used to aid in
smoking cessation, and it is also
useful in the treatment of SAD
and ADHD
Dopaminergic effect in
higher doses can
exacerbate psychosis
Its most significant
advantage is lack of
sexual side effects
NDRIs (Norepinephrinedopamine reuptake inhibitors) Management
High-yield

43. Useful in treatment of refractory major depression, major
depression with anxiety, and insomnia (secondary to side
effects).
SARIs (Serotonin antagonist and reuptake inhibitor)
High-yield
Definition

44. Mirtazapine (Remeron) useful in treatment of refractory
depression, especially in patients who need to gain weight.
NaSSAs(Noradrenergic and Specific Serotonergic
Antidepressants
Definition

45. About 70% of patients withmajor
depression will respond to antidepressant
medication.
Treating Major Depression
High-yield
Management

46. Learning Outcomes
✓You know the different broad categories of
psychiatric medications.
✓You have some understanding of when to
use what drugs in the treatment of patients
✓You are aware of some potential side
effects of medication.