1st Generation Antipsychotics Flashcards
Indication:
Psychosis (schizophrenia)
Acute mania
Agitation
Adverse effects
Dry mouth Muscle stiffness Muscle cramping Tremors EPS (akathisia, Parkinsonism, dystopia) Weight gain
Mode of action
Block D2 receptors mainly in the Mesolimbic pathway
Effects of d2 block in different pathways
Nigrostriatal - EPS
Tuberoinfundibular - endocrine
M1 blocking - drowsiness, dry mouth, blurred vision, constipation
H1 blocking - drowsiness and weight gain
A1 blocking -drowsiness, Dizziness, decreased BP
5-HT2c blocking - weight gain
STANCE mnemonic
S=sedation, sunlight sensitivity T=tardive dyskinesia A=anticholinergic, agranulocytosis N=neuroleptic malignant syndrome C=cardiac arrhythmia E=EPS
Tardive dyskinesia
Involuntary repetitive body movements
Neuroleptic malignant syndrome
Rare, but life-threatening
Fever, muscle rigidity, altered mental status, autonomic dysfunction
Main types of antipsychotics
Pheotiazines - dimethylamines - piperazine derivatives Thoxanthenes Butirophenons
1st gen antipsychotics
Pheotiazines - dimethylamines —chlorpromazine —levopromazine —promethazine - piperazine derivatives —fluphenazine Thoxanthenes —chloprothixol —zuclopenthixol (cisordinol) —flupenthixol Butriophenons —haloperidol (haldol) —droperidol
Chlorpromazine
First antipsychotic drug
- 5-HT2a>D2>M>H1>a1
- it is given in such high doses that D2 antagonism dominates
- potent H1 antagonism —> sedation
- M1 antagonism —> Parkinsonism (?)
- moderate to high potential for orthostatic hypotension (a1) and antimuscarinic effects
- for acute psychotic state
- injections
Levopromazine
Severe antihistaminic block leading to sedative effect
Not used
Promethazine
No used as antipsychotic drug
Can be used as anti-allergic and anti-emetic drug
Fluphenazine
D2»M;H1;a1
Low potential for weight gain, sedation, orthostatic hypotension and antimuscarinic effects
Chlorprothixen and flupenthixol
Derivatives of fluphenazine, not really used
Zuclopenthixol
Cisordinol
