The Singapore Family Physician

Back to issue Vol 39 No. 1 - Schizophrenia

Update on Medications in Schizophrenia

Roger Ho
The Singapore Family Physician Vol 39 No 1 - Schizophrenia
26 - 34
1 February 2013
Antipsychotics are a pharmacologically heterogeneous group of compounds, but all act as D2 dopamine receptor antagonists, an action linked to their antipsychotic effect. Today, sixty years on since 1952, we have the FGAs and the SGAs. These medications continue to be useful, and continue to have some troubling adverse effects. As a class, the FGAs are more likely to be associated with EPS but this is primarily true of medications that bind tightly with D2 neuroreceptors, such as haloperidol, and less true of medications that bind weakly, such as chlorpromazine. Anticholinergic effects are especially prominent with weaker-binding FGAs, as well as with the SGA clozapine. As a class, the SGAs, especially clozapine and olanzapine generally tend to cause more problems relating to the metabolic syndrome, such as obesity and type 2 diabetes mellitus. All antipsychotic medications are associated with an increased likelihood of sedation, sexual dysfunction, postural hypotension, prolonged QT interval and sudden death. Primary care physicians need to be familiar with the individual adverse effect profiles of these medications.