Histamine H2 antagonism as adjuvant therapy

INTERVENTION: Trade Name: Famotidin Hexal Pharmaceutical Form: Capsule INN or Proposed INN: Famotidine Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 40‐ Pharmaceutical form of the placebo: Capsule Route of administration of the placebo: Oral use Trade Name: FADUL Pharmaceutical Form: Capsule INN or Proposed INN: Famotidine Other descriptive name: FAMOTIDINE Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 20‐ CONDITION: Schizophrenia ; MedDRA version: 17.0 Level: PT Classification code 10039626 Term: Schizophrenia System Organ Class: 10037175 ‐ Psychiatric disorders Therapeutic area: Psychiatry and Psychology [F] ‐ Mental Disorders [F03] PRIMARY OUTCOME: Main Objective: To study if famotidine add‐on treatment is more effective than placebo add‐on in reducing symptoms of schizophrenia among patients receiving insufficient response to ongoing antip‐sychotic treatment. Primary end point(s): Positive and Negative Syndrome Scale (PANSS); Secondary Objective: Not applicable Timepoint(s) of evaluation of this end point: baseline, randomization, and every second week during 8 weeks treatment, end of treatment, and 2 weeks after treatment. SECONDARY OUTCOME: Secondary end point(s): Clinical Global Impression (CGI) scale ; Timepoint(s) of evaluation of this end point: baseline, randomization, and every second week during 8 weeks treatment, end of treatment, and 2 weeks after treatment. INCLUSION CRITERIA: • 18‐65 year‐old men and women with a ICD‐10 diagnosis of schizophrenia (F20.00‐20.39, F20.5, F20.9) who have had the disorder for at least 5 years and who are on disability pension. (This means that their treatment response is not satisfactory and for the purpose of this study, the subjects are potentially treatment resistant). • Clinical Global Impression (CGI) severity score of at least 3. • No changes in schizophrenia treatment within 12 weeks before study inclusion. • Written informed consent • The subjects must fulfil schizophrenia criteria both according to DSM‐IV (295.10, .20, .30, .60, .90) (American Psychiatric association) and the Research Diagnostic Criteria for schizophrenia (RDC) [40]. They must also have at least mild residual symptoms (CGI 3 points). The DSM‐IV diagnosis will be verified by use of the SCID‐I [41]. The DSM‐IV is clearly the most commonly used in psychiatric research, so this is important to be able to generalize th