Abstract
While effective as a single agent in a significant proportion of treatment refractory
patients, clozapine is often used in combination with other medications, including
classical neuroleptics (1), mood stabilizers and antidepressants (2), benzodiazepines
(3) and lithium (4). In Denmark, where clozapine has been in near continuous use since
1975, up to 60 % of clozapine patients receive additional medication (4). Classical
neuroleptics, often at antipsychotic levels, are the medications most frequently added,
and are used in 30 - 35 % of patients receiving clozapine (4, 5). Clozapine, due to
its low D2-blocking effect, may be therapeutically insufficient to contain symptoms
and additional agents may be required (4). In controlled clinical trials risperidone
has been shown to be superior to haloperidol (6), but has not yet been rigorously
compared to clozapine. In light of its established efficacy and pharmacological profile
(7) risperidone may be reasonably construed to be a medication with efficacy somewhere
between clozapine and classical neuroleptics. As such, it may be especially well suited
for use with clozapine as a part of an augmentation strategy. There are no reports
in the literature describing the concurrent use of risperidone and clozapine. We present
two cases demonstrating augmentation of clozapine's effects through combined use with
clozapine.
