ANti-parkonsonian drugs and neuroleptics-schizo

Question 1

Describe the incidence of schzophrenia, and how it affects life expentency

Answer 1

• Affects » 1% of population & has genetic influence
• Onset of symptoms: between 15-35 years
• Higher incidence in ethnic minorities (eg Afro-Caribbean immigrants)
• Patients’ life expectancy - 20-30 years lower than average

Question 2

Exokain postive and negative sysptoms of schizophrenia

Answer 2

Symptoms

Positive symptoms

• ­ IncreasedMesolimbic dopaminergic activity
• Hallucinations: Auditory & visual
• Delusions: Paranoia
• Thought disorder: Denial about oneself

Negative symptoms

• Decreased Mesocortical dopaminergic activity
• Affective flattening: lack of emotion
• Alogia: lack of speech
• Avolition/ apathy: loss of motivation

Question 3

Explain the replacements of the established drug for schizophrenia, that ocurred with the time of first generation/typical antipscychotics

Answer 3

Chlorpromazine

• Discovered whilst developing new antihistamines
• Primary mechanism of action – possibly D2 receptor antagonism

Side effects

• High incidence - anti-cholinergic, especially sedation
• Low incidence - extrapyramidal side-effects (EPS)

Haloperidol

• Very potent D2 antagonist (~ 50x more potent than chlorpromazine)
• Therapeutic effects develop over 6-8 weeks
• Little impact on negative symptoms

Side effects

•High incidence - EPS

Question 4

Mechainism of action of clozepine

Answer 4

Question 5

Discuss efficacy , mechanism of action and side effects of commonly used sencond generation/atypical antipscychotics

Answer 5

Clozapine

• Most effective antipsychotic
• Very potent antagonist of 5-HT2A receptors
• Only drug to show efficacy in treatment resistant schizophrenia & negative symptoms

Side effects

•Can cause potentially fatal neutropenia, agranulocytosis, myocarditis & weight gain(these set of side effects are why it is used as a last resort)

Risperidone

•Very potent antagonist of 5-HT2A & D2 receptors

Side effects

•More EPS & hyperprolactinaemia than other atypical antipsychotics

Quetiapine

•Very potent antagonist of H1 receptors

Side effects

•Lower incidence of EPS than other antipsychotics

Aripiprazole

•Partial agonist of D2 & 5-HT1A receptors( in theory should mean that it reverses an pathological changes in dopamine levels however does not happen in practice therefore No more efficacious than typical antipsychotics)

Side effects

•Reduced incidences of hyperprolactinaemia & weight gain than other antipsychotics

Question 6

WHen did first generationa nd second generation antipsychotic/ neuroleptics begin to be discovered

Answer 6

1950s for 1st genration and 1970s for 2nd generation

Question 7

Recall times when sencond generation/atypical antipscychotics were discovered

Answer 7