Therapeutics - Schizophrenia

Question 1

Describe the pathophysiology of schizophrenia

Answer 1

Dopamine theory
Xs dopamine rece activation

5HT theory
Xs 5HT rece antagonism improve -ve symptoms

Glutamate theory
Drugs which block NMDA rece channel produce sx sim to acute schizo

Question 2

Describe the aetiology of schizophrenia

Answer 2

Genetics
- Potential loci ID on chr 6,8,13,15,22
- 50% risk in monozygotic twin, 12-14% dizygotic twins, 40% both parents
- DiSC1, neuregulin-1, dysbindin-1, COMT

Neurodev abnormalities, effects
Personality
Physical & psychological and social factors in infancy & early childhood

Cerebral tumours or injury
Drugs/sub induced
- Alc, benzo, barbiturates, antidepressants, GCs, CNS stimulants, hallucinogens, BB, dopamine agonists
Personal misfortune
Env of high xp emotion

Stress
Lack of support
Social withdrawal
Poor adherence to antipsychotic meds
Secondary demoralisation

Question 3

What are the risk factors of schizophrenia

Answer 3

Genetics
Late adolescence, early childhood
- Males: early 20s, Females: late 20s to early 30s

Question 4

Describe the epidemiology of schizophrenia

Answer 4

1% lifetime incidence
0.3% prevalence

Question 5

What are the signs and symptoms of schizophrenia?

Answer 5

A. 2 or more of the following, each persisting for sig portion of at least 1mo period
Delusion
Hallucination
Disordered speech
Grossly disordered or catatonic behaviour
-ve sx: affective flattening, avolition (lack of motivation)

B. Social/occupational dysfn
C. Duration
- Continuous signs of disorder for at least 6mo
- Inclusive of min 1mo of symptoms fulfilling criteria A unless successfully treated
- 6mo may incl prodromal or residua; sx

D. Schizoaffective or mood disorder has been EXCLUDED
E. Disorder is NOT due to medical disorder or sub use
F. If Hx of pervasive dev disorder is present, must be sx of hallucinations or delusions present for at least 1mo

Aggressive sx
Anxiety/depression (in 10% of schizo pts)

Question 6

What are the pharmacological agents available for schizophrenia management?

Answer 6

Antipsychotics
Benzodiazepine

Question 7

What are the principles of management for schizophrenia?

Answer 7

1. Single monothera FGA or SGA (except Clozapine)
2. If inadequate response after adequate trial: switch to another FGA or SGA (except Clozapine)
3. If treatment resistant (fail >=2 adequate trials): Clozapine
4. If refuse clozapine, insuff resp: combi agents (2FGA or FGA+SGA) or antipsychotic + ECT
5. If pt non-adherent: IM antipsychotics
   IM haloperidol
   IM risp/aripiprazole
6. If responding well: cont treatment

Question 8

What is an adequate trial?

Answer 8

Min 80% compliance @ optimal dose for 2-6 weeks. Req 3mo to confirm treatment resp. If another antipsychotic added to clozapine, add on another 8-10 week trial.

Question 9

What are the non-pharm management for schizophrenia?

Answer 9

CBT
Interactive/Social thera
ECT - reserved for treatment resistant schizophrenia

Question 10

What are the monitoring parameters in schizophrenia?

Answer 10

EPSE
Wt, BMI, waist circumference
FGB
Lipid panel
FBC (for clozapine)
ECG
Prolactin
BP, HR

Question 11

What are the stages of schizophrenia management?

Answer 11

Acute phase
- If pt cooperative
- If pt uncooperative
- If catatonia

Stabilisation/maintenance phase

Question 12

What are the recommendations for if a pt is cooperative during the acute phase?

Answer 12

PO lorazepam 1-2mg or PO antipsychotic

Question 13

What are the recommendations for if a pt is uncooperative & remains agitated/aggressive in the acute phase?

Answer 13

IM lorazepam
IM haloperidol/olanzapine/aripirazole/promethazine
IM lorazepam + haloperidol
IM haloperidol + promethazine

Question 14

What are the recommendations for if the pt is catatonic during the acute phase?

Answer 14

PO/IM benzodiazepines or ECT

Question 15

What are the recommendations for if the pt is depressive and/or has -ve sx in the acute phase?

Answer 15

Antidepressants