Schizo Flashcards
First line therapy for schizophrenia
Monotherapy FGA or SGA, except clozapine
If first antipsychotic fails to show response or improvement, what is the next line of therapy?
Use another monotherapy FGA or SGA, except clozapine (switch FGA/SGA)
Goals of pharmacological treatment of schizophrenia?
- Relieve symptoms of psychosis
- Prevent relapse (because more relapse = more treatment resistant)
Describe the four tracts of the central dopamine system that antipsychotics target
- Mesolimbic tract: Blocks dopamine receptors here. Responsible for positive symptoms in schizophrenia
The following causes AEs of antipsychotics
1. Mesocortical tract: Dopamine blockage here result in negative symptoms
2. NIgrostriatal tract: EPSE
3. Tuberoinfundibular tract: hyperprolactinemia from dopamine blockage
What is an adequate trial of antipsychotic?
Try a new antipsychotic on a patient for 2-6 weeks before determining if it is useful for the patient or not
In an acute agitation, state the drug class to manage the patient
BZD
If patient is cooperative in an acute agitation, what is the first line option?
ORAL lorazepam 1-2mg
or
- Haloperidol 2-5mg, risperidone 1-2mg, quetiapine 50-100 mg, olanzapine orodispersible 5-10mg
If patient is Uncooperative in an acute agitation, what is the first line option?
IM lorazepam 1-2 mg
OR
- IM olanzapine 5-10 mg
- IM aripiprazole 9.75 mg
- IM haloperidol 2.5 - 10 mg (with pre-treatment ECG)
- IM promethazine 25-50 mg
First line treatment for acute agitation related to catatonia?
BZDs (because catatonia involves deactivation of GABA, so BZD is very effective since it is a GABA activator)
Common adverse effect of FGAs (and is more prominent than SGAs)
- EPSE
- Hyperprolactinemia
Usual dosage range of haloperidol
5 - 15 mg a day
(0.5 - 3 mg/ BD - TDS)
(3-5 mg BD-TDS for severe symptoms)
Usual dosage range of olanzapine. State one important adverse effect
5 - 20 mg a day (usual 10 mg OD)
- Weight gain (hence balanced diet is important)
Management of dystonia in patients taking antipsychotics
IM anticholinergics (e.g. benztropine)
Management of dystonia in patients taking antipsychotics
- Decrease or switch to SGA
- Anticholinergics PRN (e.g. benzhexol)
Management of Akathisia in patients taking antipsychotics
- Decrease or switch SGA
- Low dose clonazepam PRN
Management of tardive dyskinesia in patients taking antipsychotics
- Discontinue anticholinergics (important!!)
- Decrease or switch antipsychotics to SGA
- Valbenazine 40-80mg/day
- Note: symptom worsen with anticholinergic drugs
Management of hyperprolactinemia in patients taking antipsychotics
Switch to aripiprazole if it is a problem
Antipsychotics with metabolic side effects and sedation. What are the metabolic side effects?
Drugs: Olanzapine, clozapine, quetiapine
Metabolic side effects: Weight gain, diabetes, increased lipids
- Management: treat conditions. Switch to aripiprazole or lurasidone if really necessary
One prominent CNS side effects of antipsychotics characterised by muscle rigidity, fever, altered consciousness, etc. How to manage?
Neuroleptic malignant syndrome (muscle rigidity, fever, autonomic dysfunction, altered consciousness etc.)
Treatment: IV dantrolene 50 mg TDS, or oral dopamine agonist
Important side effect of clozapine
Agranulocytosis.
- Monitor weekly for the first 18 weeks, then monthly
Drug interaction with clozapine which may increase the risk of agranulocytosis?
Carbamazepine (coz it also can cause agranulocytosis)
SGA are able to improve mood sx and negative symptoms via what kind of mechanism of action?
5HT2A antagonism
A long acting FGA given via the IM route. State its dosing range.
IM Haloperidol decanoate 50 - 300 mg/4 weeks
(or 25 - 150 mg / 2 weeks)
A long acting FGA given via the IM route. State its dosing range.
IM Haloperidol decanoate 50 - 300 mg/4 weeks
(or 25 - 150 mg / 2 weeks)
