Antipsychotic Drugs & Mood Stabilizers Flashcards
What are the TYPICAL antipsychotics?
1st gen
Haloperidol, Chlorpromazine
What are the ATYPICAL antipsychotics?
2nd gen
Clozapine, Risperidone, Olanzapine, Aripiprazole, Quetiapine
What are the 3 Sx’s of Schizophrenia and dopaminergic pathways?
- (+) Sx’s
- (-) Sx’s
- Cognitive dysfunction
What are the (+) Sx’s of Schizophrenia?
- Hallucinations
- Delusions
- Disorganized thought
What are the (-) Sx’s of Schizophrenia?
- Affective blunting; Apathy; Anhedonia (like depression)
- Social withdrawal
What are the Cognitive dysfunction Sx’s of Schizophrenia?
- Declines in attention, language, memory, executive function
What are the 2 parts of the Dopamine hypothesis?
Amphetamine
- Hyperactivity, extreme anxiety, paranoid delusions, hallucinations…..
- Membrane dopamine transporter (can inhibit reuptake & therefore buildup & dopamine can cause psychosis)
Antipsychotic drugs
- Antipsychotic drugs tend to block dopamine
receptors in the dopamine pathways of the brain.
What 4 parts of the Dopaminergic pathways?
- Mesolimbic pathway
- Mesocortical pathway
- Nigrostriatal pathway
- Tuberoinfundibular pathway
What is the Mesolimbic pathway?
- VTA (Ventral Tegmental Area) →(projects to) → Nucleus accumbens in the ventral striatum
- Motivation, reward, addiction, reinforcing behaviour
- HYPERACTIVITY → POSITIVE SYMPTOMS
(A Dopaminergic pathway)
What is the Mesocortical pathway?
- VTA →(projects to) → Prefrontal cortex
- Cognitive function, motivation and emotional response.
- DEFICIT → NEGATIVE SYMPTOMS,
- DEFICIT → COGNITIVE DYSFUNCTION
(A Dopaminergic pathway)
What is the Nigrostriatal pathway?
- SNc (substantia nigra) →(projects to) → caudate nucleus and putamen in the dorsal striatum
- MODULATE MOTOR ACTIVITY, part of the basal ganglia motor loop.
(A Dopaminergic pathway)
What is the Tuberoinfundibular pathway?
- infundibular nucleus in hypothalamus →(projects to) → pituitary gland
- regulates the secretion of prolactin (which)→ INHIBITS PROLACTIN RELEASE.
(A Dopaminergic pathway)
What are antipsychotic drugs?
Antipsychotic drugs are able to REDUCE PSYCHOTIC SYMPTOMS in a wide variety of conditions, including schizophrenia, bipolar disorder and others.
What is the classification of Antipsychotic drugs?
- TYPICAL antipsychotics (1st generation):
– chlorpromazine, haloperidol - ATYPICAL antipsychotics (2nd generation):
– clozapine, risperidone, olanzapine,
quetiapine, aripiprazole
What is the action sites of the TYPICAL antipsychotics (first generation): chlorpromazine, haloperidol?
- BLOCK DOPAMINE D2 RECEPTOR: binding affinity is strong
- NON-SELECTIVELY BLOCK: histamine H1 receptor; muscarinic M receptor; adrenergic α receptor
NO EFFECT ON 5-HT receptor
What is the therapeutic uses of TYPICAL antipsychotics (first generation): chlorpromazine, haloperidol?
- Onset of action is about 1 WEEK
- Effective for POSITIVE symptoms (block Mesolimbic pathway) but not effective for negative symptoms (NO EFFECT ON (-) & Cognitive Sx’s)
- Inhibit D2 receptor in mesolimbic DA pathway → positive symptoms ↓
Why are TYPICAL antipsychotics effective for (+) Sx’s but not (-) Sx’s?
b/c only for psychosis; b/c blocks dopamine D2 r.; inhibiting it
- for (-) Sx’s, you’d want to UPregulate dopamine
What are the adverse effects of TYPICAL antipsychotics (first generation): chlorpromazine, haloperidol?
EXTRAPYRAMIDAL SYMPTOMS (EPS):
- block DA nigrostriatal pathway (which controls motor movement)
- Short-term Tx (hours-months):
– Parkinson’s syndrome
– Akathisia, acute dystonia
– REVERSIBLE
- Long-term treatment (months-years):
- Tardive dyskinesia (repetitive, invol, purposeless movements)
- IRREVERSIBLE
NEUROLEPTIC MALIGNANT SYNDROME:
- A rare but life-threatening reaction (high fever, rigid muscles, etc.)
GALACTORRHEA:
- block tuberoinfundibular pathway: spontaneous flow of milk from breast
OTHER:
- ANTIMUSCARINIC, ANTIHISTAMINERGIC, ANTIADRENERGIC
What are the action sites of ATYPICAL antipsychotics (second generation)
(clozapine, risperidone, olanzapine, quetiapine, aripiprazole)?
- Block dopamine D2 receptor
- Block 5-HT2 receptor
What are the therapeutic uses of ATYPICAL antipsychotics (second generation)
(clozapine, risperidone, olanzapine, quetiapine, aripiprazole)?
- Onset of action is about one week
- Useful for BOTH POSITIVE and
NEGATIVE symptoms
For positive symptoms:
- SIMILAR EFFICACY with typical antipsychotics
- Inhibit D2 receptor in mesolimbic DA pathway → positive symptoms↓
For negative symptoms:
- Block 5-HT2 receptor → ↓Negative symptoms, cognitive dysfunction
Clozapine: reduce suicidal risk in patients with schizophrenia
What is unique about Clozapine (Atypical)?
only one that can REDUCE suicidal risk in patients with schizophrenia