Improvement of schizophrenia negative and positive symptoms with amantadine as add-on therapy to antipsychotics: a case series.

Melhora dos sintomas positivos e negativos da esquizofrenia com o uso coadjuvante de amantadina aos antipsicóticos: série de casos Dear Editor, It has been suggested that glutamate deregulation may be involved in the neuropathology of schizophrenia (SZ), mainly through N-methyl-d-aspartate receptor (NMDA) dysfunction. Memantine, a drug approved by the FDA for the treatment of moderate to severe Alzheimer’s disease, acts as weak non-selective NMDA receptor antagonist. Our group conducted the first randomized placebo-controlled clinical trial with memantine adjunctive to clozapine for the treatment-refractory SZ. To our surprise, the improvement was not only in negative symptoms, and we have also found improvement in positive symptoms and cognition. We report the results of Amantadine, a memantine’s derivate, as adjunctive therapy to antipsychotics in four cases of DSM-IV SZ. The four subjects were clinically stabilized, but presented with a pronounced motor retardation, blunted affect, emotional withdrawal and anxiety, scoring at least 3 for each of these items at The Brief Psychiatric Rating Scale (BPRS). The subjects gave informed consent for experimental use of amantadine with the dose increased up to 400mg/day over 6 weeks. Clinical response was assessed using BPRS at baseline and at sixth week and Clinical Global Impression Improvement scale (CGI-I) at the sixth week considering: -3 = very much worse, -2 = much worse,