156 Risperidone has been found to be more effective than conventional antipsychotics for positive and affective symptoms in patients with acute schizophrenia.36 For patients with treatment resistance, the most rigorouslydefined double -blind trial found a 24% response rate to risperidone, compared with 11% for haloperidol after 4 weeks.157 A few other double-blind studies have compared risperidone
with see more clozapine and found similar response Inhibitors,research,lifescience,medical rates between drugs, but concerns about the inclusion criteria have been raised.158,159 Another open study by Flynn et al160 reported response rates to clozapine of 44%, compared with 28% to risperidone. It appears from the data available that risperidone is not associated with a clozapine-like response, but is associated with response rates of approximately 25%, higher than those of conventional antipsychotic treatments. A few studies have reported favorable response rates to olanzapine in patients with treatment-resistant Inhibitors,research,lifescience,medical schizophrenia of 36% to 47%. 161-163 However, there is some controversy regarding these
findings. These studies included patients Inhibitors,research,lifescience,medical who were considered treatment-resistant and those who were intolerant to clozapine. A study by Conley et al164 in well-characterized, treatment-resistant patients with schizophrenia found only a 7% response rate to olanzapine in this population and 41% of these treatment failures went on to respond to clozapine.165 Likewise, an open trial of olanzapine in treatment-refractory Inhibitors,research,lifescience,medical patients reported no significant improvements in patients treated for at least 6 weeks on 10 to 20 mg/day.166 Therefore, olanzapine does not have a pattern of response similar to clozapine in a wellcharacterized sample, but may offer a slightly better rate of response than traditional antipsychotic therapy.
Very little data on quetiapine use in treatment-resistant schizophrenia are available. A few brief reports suggest it may be beneficial Inhibitors,research,lifescience,medical to chronic or partial conventional rcsponders167,169; however, no controlled trials for treatment resistance have been published. If patients remain refractory to treatment after trials of SGAs, alternative therapies should be considered. Most of the data for adjunctive treatment arc, however, limited and come from case reports and open trials. Adjunct lithium therapy has been seen to be beneficial in and some patients with treatment-resistant schizophrenia; however, these patients were often not defined by the rigorous criteria of later studies.123,129,170 The published trials of adjunct lithium that are positive were conducted with small numbers of patients, and the criteria for defining treatment resistance were often not clear, or were overinclusive.171 More recent reports have found no benefits with adjunct lithium therapy and fluphenazine decanoate.172 A recent report of 5 male patients with schizophrenia treated with olanzapine showed significant improvements with the addition of lithium.