Typical (1st generation) antipsychotics Flashcards
Typical antipsychotics - 7 drugs
Chlorpromazine Fluphenazine Thioridazine Haloperidol Trifluoperazine Thiothixene Loxapine
Typical antipsychotics - MOA
Blockade of D2 receptors in mesolimbic pathway represses positive symptoms within 1-3 weeks. Blockade of D2 receptors in basal ganglia cause adverse effects.
Typical antipsychotics - adverse effects caused by D2 blockade
Tuberoinfundibular pathway: Increased prolactin levels, gynecomastia, menstrual irregularities.
EPSs:
1. Akathisia
2. Psuedoparkinsonism
3. Dystonias: oculogyric crisis, glossospasm, tongue protrusion, torticollis, life-threatening pharyngeal dystonias
Typical antipsychotics - adverse effects caused by supersensitivity and effect on hypothalamus
Supersensitivity: Tardive dyskinesia - Abnormal facial movements, abnormal limb and truncal movements.
Hypothalamus: Poikilothermy, heat stroke, hypo- and hyperthermia.
Potency of the different typical antipsychotics
Low potency: Chlorpromazine, thioridazine.
Medium potency: Loxapine.
High potency: Fluphenazine, haloperidol, trifluoperazine, thiothixene.
Thioridazine - adverse effects
Pigmentary retinopathy and cardiac toxicity (high doses). Fewer EPSs.
Greater anticholinergic effect.
Poikilothermy.
Haloperidol - indications
Schizophrenia
Tourette syndrome
Typical antipsychotics - general interactions
Additive effects with antiadrenergic, anticholinergic, CNS depressants. Betablockers and antidepressants may increase levels of both drugs.
Which typical antipsychotics may decrease the levels of lithium?
Chlorpromazine
Thioridazine
Trifluoperazine
Typical antipsychotics with more EPSs
Fluphenazine
Haloperidol
Haloperidol - interactions
Barbiturates and carbamazepine decrease serum levels.
Quinidine increases serum levels
Typical antipsychotics with fewer autonomic effects
Fluphenaizne
Typical antipsychotic with a greater anticholinergic effect
Thioridazine
Administration of antipsychotics
Chlorpromazine: Oral, IM, IV Fluphenazine: Oral, IM Thioridazine: Oral Haloperidol: Oral, IM Trifluoperazine: Oral, IM Thiothixene: Oral, IM Loxapine: Oral, IM