"Awakenings" - A transient phenomenon with risperidone

The use of risperidone in the demented elderly has increased dramatically because of its high potency and low side effect profile. A demented patient with severe paranoia was treated with risperidone after failure with several typical neuroleptics. With risperidone, there was a dramatic, but transient, reaction-an "awakenings" phenomenon. Yet with another atypical, olanzapine, the dramatic effect was more permanent. This "awakenings" effect with risperidone has not been reported previously. Typical neuroleptics act via the dopaminergic system but have severe side effects. The atypical neuroleptics, with a greater affinity for the serotonergic and adrenergic systems, have lower side effect profiles and accordingly are recommended for use in the elderly. However, increasing the dose of risperidone causes a safety profile similar to a typical neuroleptic, because of its high affinity for D2 dopaminergic receptors. In contrast, olanzapine has a low affinity for D2 receptors. We propose that this may explain why there was this "awakenings" phenomenon for risperidone and not for olanzapine.