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Flashcards in Antidepressants Deck (18)
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1
Q

Types of antidepressants

A
  • MAOIs
  • TCAs
    (imipramine, amitriptyline, nortriptyline)
  • SSRIs,
    (fluoxetine, citalopram)
  • selective NA uptake inhibitors, (NARI)
    (reboxetine)
  • non-selective 5HT/NA uptake inhibitors (SNRI)
    (venlafaxine, duloxetine)

Mirtazapine
Bupropion
Agomelatine
Ketamine

2
Q

Major clinical depression causes

A

Major cause of work days lost to disability.

Major cause of premature death.

3
Q

Symptoms of depression

A

 Emotional
• Misery, apathy, and pessimism
• Low self-esteem (feelings of guilt, inadequacy and ugliness)
• Indecisiveness, loss of motivation

 Other domains
• Retardation of thought and action
• Loss of libido
• Sleep disturbance and loss of appetite

duration of symptoms >6months

4
Q

Types of depression

A

 Unipolar depression
• Mood swings always in the same direction

 Bipolar depression or affective disorder
• Alternating depression and mania

5
Q

Types of Unipolar depression

A

 Reactive Depression (about 75 % of cases)

• non-familial
• associated with life-events
• accompanied by symptoms of anxiety and agitation
anxiety and depression hard to differentiate normally co-exist

 Endogenous Depression (about 25 % of cases)
• familial pattern
• not directly related to external stress

6
Q

Reactive depression

A

 Reactive Depression (about 75 % of cases)

• non-familial
• associated with life-events
• accompanied by symptoms of anxiety and agitation
anxiety and depression hard to differentiate normally co-exist

UNIpolar

7
Q

endogenous depression

A

 Endogenous Depression (about 25 % of cases)
• familial pattern
• not directly related to external stress

UNIpolar

8
Q

bipolar depression

A

 Depression alternates with mania
 Periodicity of oscillations in mood vary but usually occur over several weeks
 Usually appears in early adulthood
 Strongly familial
 Some studies suggest genetic similarities to susceptibility to schizophrenia
 Drugs used to treat depressive symptoms still usually include antidepressants

9
Q

theory to explain depression

A

Monoamine theory
 Deficits in monoamine neurotransmitters (noradrenaline and 5-HT) cause depression.
 Basis of most successful pharmacological strategies for treatment of depression.

  • observed from reserpine which inhibits NA and 5-HT storage, depressed mood.
10
Q

limitation of monoamine theory

A

 Hypothesis originally formulated for noradrenaline, but later emphasis shifted to 5-HT.

 Studies of monoamine markers in depressed patients have yielded inconsistent and equivocal results.

 Monoamine hypothesis alone is inadequate to explain all pharmacological actions in depression

11
Q

Monoamine oxidase (MAO)

A

 Found in nearly all tissues, including nerve terminals, intestine, and liver.
 Found intracellularly, mostly on the mitochondrial surface.
 Breaks down monoamines.

Two major forms, MAO-A and MAO-B:
 5-HT broken down mainly by MAO-A.
 Both forms act on noradrenaline (NA) and dopamine.

MAO-B selective inhibitors (e.g. selegiline) are used in Parkinson’s disease.

 MAO inhibitors (MAOIs) increase biological availability of monoamines.
 MAOIs such as phenelzine are used as antidepressants.

Phenelzine is:
 Non-selective for MAO-A versus MAO-B.
 An irreversible MAO inhibitor.

12
Q

Tricyclic Antidepressants (TCAs)

A

Initially produced as potential antipsychotic drugs in 1949 but found to be ineffective in schizophrenia.

Non-selective for SERT/NET:
Imipramine, Amitriptyline, nortriptyline

Selective for NET:
Desipramine

SERT: serotonin transporter
NET: norepinephrine transporter

13
Q

Nortriptyline

A

 Second generation TCA
 Milder side effects compared to amitriptyline and imipramine
 Improved compliance

14
Q

Selective Serotonin reuptake Inhibitors (SSRIs) are the first drug class developed for the purpose of antidepressant treatment

A

Selective Serotonin reuptake Inhibitors (SSRIs) are the first drug class developed for the purpose of antidepressant treatment

15
Q

SSRI

A

 Greater 5-HT reuptake selectivity than TCAs.
 50- to 1000-fold selectivity for 5-HT over NA.
 Fluoxetine approximately 50-fold selectivity for 5-HT.  Citalopram approximately 1000-fold selectivity for 5-HT.

 Fewer adverse effects than TCAs.

16
Q

currently the most widely prescribed antidepressant.

A

Fluoxetine

17
Q

Noradrenaline Reuptake Inhibitors (NARIs)

A

 Greater NA reuptake selectivity than TCAs.
 Approximately 1000-fold selectivity for NA over 5-HT.  Reboxetine approximately 1000-fold selectivity for NA.
 Fewer adverse effects than TCAs and SSRIs.

18
Q

Serotonin and Noradrenaline reuptake Inhibitors (SNRIs)

A

 Similar dual 5-HT and NA reuptake inhibition profiles to non-selective TCAs.
 Issue of additional receptor antagonism is controversial.
 Venlafaxine, desvenlafaxine(synthetic metabolite of venlafaxine) and duloxetine are examples in clinical use.