Antipsychotic Agents Flashcards

1
Q

Clinical Features of Schizophrenia

Positive symptoms

A

overactivity of dopamine neurons in the limbic system (mesolimbic pathway)

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2
Q

Clinical Features of Schizophrenia

Psychotic Symptoms

A

Delusions: false belief, often paranoid in nature

Hallucinations: false perception, usually voices

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3
Q

Clinical Features of Schizophrenia

Disorganized symptoms

A

Thought disorders–> wild trains of thought with irrational conclusions (inserted by an outside agency)

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4
Q

Clinical Features of Schizophrenia

Negative symptoms

A

hypoactivity of dopamine neurons in the prefrontal cortex (mesocortical pathway)

  • Withdrawal from social contact
  • Flattening of emotional responses
  • Decreased motivation
  • Poverty of speech
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5
Q

Clinical Features of Schizophrenia

Cognitive symptoms

A

Decreased attention span-executive function

Poor working memory

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6
Q

Abnormality of brain function in schizophrenics is due to overactivity in brain dopaminergic pathways, especially in the mesolimbic pathway

A

Dopamine Hypothesis of Schizophrenia

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7
Q

Virtually all antipsychotic drugs block __________ receptors

A

dopamine D2

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8
Q

Evidence exists for role of _______ (3) systems in SK

A

glutamate and serotonin and acetylcholine

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9
Q

↑ DA –>

A

Positive Symptoms
Delusions
Hallucinations
Disordered thoughts

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10
Q

↓ DA –>

A

Negative Symptoms
Blunted affect-anhedonia
Alogia - Asociality

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11
Q

Subserve the integration of sensory input and motor responses with affective or emotional data

A

Mesolimbic pathway

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12
Q

Involved in communication and social abilities

A

Mesocortical pathway

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13
Q

Part of basal ganglia (aka extrapyramidal tract) plays a central role in planned, coordinated movement

A

Nigrostriatal pathway

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14
Q

Hypothalamic neurons release DA in pituitary to inhibit prolactin release

A

Tuberoinfinduibular pathway

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15
Q

5HT2A receptors on DA neurons in the PFC decrease DA release. Block of these receptors by atypical agents results in _______ resulting in alleviation of negative symptoms of schizophrenia

A

Serotonin Hypothesis - 5HT2A Receptors

increased DA release

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16
Q

Activation of _______ was found to be basis of hallucinatory effects of drugs like LSD and mescaline

A

Serotonin Hypothesis - 5HT2A Receptors

5HT2A

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17
Q

________ on DA neurons in the PFC decrease DA release. Block of these receptors by atypical agents results in increased DA release resulting in alleviation of negative symptoms of schizophrenia

A

Serotonin Hypothesis - 5HT2A Receptors

5HT2A receptors

18
Q

Glutamate Hypofunction Hypothesis

A

Cortical Glu –> GABA–> cortical Glu –> ↑ mesolimbic DA

Hypofunction in cortical NMDA-Glu neurons -remove GABA inhibition-activate DA Neurons -positive symptoms of schizophrenia

19
Q

Positive symptoms of schizophrenia (delusions, hallucinations) are believed to result from:

A

Overactivity of cholinergic neurons in the cortex

Overactivity of dopamine neurons in the mesolimbic system

20
Q

Cortical Glu –> GABA –> Glu –> GABA –> ↓ mesocortical DA

A

Glutamate Hypofunction Hypothesis

Hypofunction in cortical NMDA-Glu neurons remove inhibition of VTA GABA inhibit mesocortical DA negative symptoms of schizophrenia

21
Q

TYPICAL VS ATYPICAL

A

Typical Agents [1st generation] – high D2 / 5HT2A blocking ratio

Atypical Agents [2nd generation] - low D2/5HT2A blocking ratio

22
Q

Typical Agents [1st generation] – high D2 / 5HT2A blocking ratio

A

Good D2 block - good efficacy against positive symptoms

Good D2 block - high incidence of extrapyramidal toxicity

23
Q

Atypical Agents [2nd generation] - low D2/5HT2A blocking ratio

A

Poor D2 block yet good antipsychotic efficacy (atypical)

Good 5HT2A block good efficacy against negative symptoms

Poor D2 block + good 5HT2A block reduced incidence of EPSE

24
Q

Haloperidol

A

High potency ↑ D2 side effects (EPSE) but less ADRs via M-H1-α1 block

25
Chlorpromazine
↓ EPSE, but ↑ ADRs from M-H1-α1 block Low potency
26
Atypical Agents (2nd generation)
``` #42: Quetiapine (Seroquel®) #79: Aripiprazole (Abilify®) #84: Risperidone (Risperdal®) #145: Olanzapine (Zyprexa®) Ziprasidone (Geodon®) Clozapine (Clozaril®) ```
27
Typical Agents (1st generation)
Haloperidol (Haldol®) | Chlorpromazine (Thorazine®)
28
Olanzapine
Atypical Agents (2nd generation)
29
Haloperidol
Typical Agents (1st generation)
30
Risperidone
Atypical Agents (2nd generation)
31
Aripiprazole
Atypical Agents (2nd generation)
32
Quetiapine
Atypical Agents (2nd generation)
33
Chlorpromazine
Typical Agents (1st generation)
34
Atypical antipsychotic agents such as clozapine or olanzapine are distinguished from typical agents such as haloperidol because they are associated with a lower incidence of:
Extrapyramidal side effects Defines them, makes them atypical
35
Adverse Reactions | Muscarinic block – ↑ with typical-low potency
Dry mouth Blurred vision Urination difficulty Constipation Tachycardia Sedation
36
Alpha-1 adrenergic block | ↑ with typical-low potency
Orthostatic hypotension
37
H1 Histamine block | ↑ with typical-low potency
Sedation **Weight gain --> risk of Type 2 diabetes**
38
D2 Block – _______________- ↑ with typical-high potency
Extrapyramidal Side Effects
39
D2 Block | Extrapyramidal Side Effects early
* Acute dystonia (onset 1-5 days) - -Torticollis, trismus, opisthotonos - -rx: anticholinergic agents [diphenhydramine-benztropine] * Akathisia (onset 6-60 days) - -Motor restlessness – “can’t sit still” - -rx: reduce dose – change drug – try anticholinergic, β blocker or benzodiazepine
40
D2 Block – Extrapyramidal Side Effects late
*Pseudoparkinsonism (onset 5-90 days) - Tremor, bradykinesia, rigidity, shuffling gait - Rx: anticholinergic agents *Tardive dyskinesia (onset 3-6 months or longer, 20-40% incidence in elderly females) - D2 receptor supersensitivity? - Involuntary movements of orofacial muscles, choreathetoid* movements - rx: rarely effective, prevention best strategy