5 mg/day.10 At these dose levels, risperidone’s motor side effects are minimal, although they do

increase at daily doses above 6 mg/day. Risperidone has been widely prescribed and well received. Galactorrhea secondary to elevated prolactin levels is one of its major side effects and a moderate weight gain is apparent. Risperidone has been studied Inhibitors,research,lifescience,medical in psychosis of dementia and found to be therapeutic at the lower dose range of 1 to 2 mg/day. Olanzapine was approved in the US approximately a year after risperidone. The drug has a broad receptor affinity profile, similar to that of clozapine, except for a generally higher receptor affinity at each site. Its GDC-0449 mouse antipsychotic action tested against haloperidol is at least comparable, with both drugs showing significantly better effects than placebo.11 With respect to its therapeutic action, olanzapine has broader effects than a traditional compound like haloperidol, with some antianxiety, antidepressant, and arguably antinegative symptom actions as well.12 Olanzapine has been tested in Inhibitors,research,lifescience,medical the psychosis of bipolar illness and found to be therapeutic. Olanzapine’s side effects are mostly benign, with no parkinsonism, mild akathisia, and no blood dyscrasias or prolactin elevations. Significant weight gain and its Inhibitors,research,lifescience,medical consequences, including adult-onset diabetes and hyperlipidemia, are its Inhibitors,research,lifescience,medical most significant side effects. Quctiapinc was

the third new antipsychotic to be approved worldwide for psychosis. This low affinity but broad spectrum compound (like clozapine) is an effective antipsychotic.13 Worldwide use has been relatively low, despite its efficacy and attractive side-effect profile: “placebo-level” parkinsonism and akathisia with no prolactin elevation but moderate weight gain. Moreover, quetiapine has been studied in the psychosis of dementia with oral reports of good activity.14,15 Ziprasidone Inhibitors,research,lifescience,medical is due to be released onto the US market in early 2001. Efficacy and side-effect data for this

promising compound are forthcoming. Amisulpride is an antipsychotic available in several European countries, but not yet in the US. Its antipsychotic efficacy has been demonstrated, Rolziracetam together with a low, but not “placebo” level, motor side-effect profile. Several studies have suggested an antinegative symptom profile for this drug. Such a unique characteristic has not yet been rigorously demonstrated, but repeatedly suggested in the literature. Even beyond these compounds, the industrial pipelines for new antipsychotics are not dry.16 Newer drugs are being tested in all stages of trials: phases 1 through 4. Currently, all the compounds under study block D2 dopamine receptors, but additional novel strategies are also being evaluated, like partial dopamine agonists17 and indirect-acting N-methyl-D-aspartate (NMDA)-sensitive glutamate agonists.