To Assess the Efficacy and Safety of Ceftriaxone in Patients With Mild to Moderate Parkinson's Disease Dementia

This is a randomized, double blinded, placebo-controlled Phase II study to investigate the efficacy and safety of ceftriaxone in patients with mild to moderate Parkinson's disease dementia (PDD).This study will enroll approximately 106 patients to have up to 84 evaluable subjects, and conduct in Chung Shan Medical University Hospital, National Taiwan University Hospital, Kaohsiung Chang Gung Memorial Hospital, China Medical University Hospital, Changhua Christian Hospital, and Taipei Veterans General Hospital.

Inclusion Criteria: 1. Patients are male or female, age 50-85 years, inclusive. 2. Diagnosis of idiopathic Parkinson's disease (PD) based on the UK Parkinson's Disease Society Brain Bank Criteria and with a modified Hoehn and Yahr Stage of I to IV. 3. Patients have been receiving stable dose of medications equivalent up to 1800 mg/day of levodopa for Parkinson's disease at least 2 weeks prior to screening and patients are considered as being optimally treated at screening and no known further adjustments of current medication needed to improve the subject's status of PD during the study period by the judgment of the Investigator based on the subject's history, previous treatments, and the clinical presentation. 4. Diagnosis of PDD based on Movement Disorder Society (MDS) Task Force criteria as the following items: 1. A diagnosis of PD based on UK Parkinson's Disease Society Brain Bank Criteria 2. PD development prior to the onset of dementia based on patient/caregiver history or records 3. Cognitive deficiency severe enough to impair daily life based on patient/caregiver interview or questionnaire 4. Impairment of at least 2 of the following domains: attention, executive function, visuo-constructive ability, memory Besides, patients' Mini-Mental State Examination (MMSE) should be in the range of 18-25 (inclusive) or CDR scale in the range of 0.5-2. Note that MMSE range 16-25 for illiterate. Illiterate is defined as no education history. 5. Patients who are eligible and able to participate in the study must be judged by the investigator to evaluate the competency of providing informed consent for this dementia related study (the decision making is based on MacArthur Competence Assessment concept) and should be able to understand the language in which the tests require so and must be able to perform all the assessments. 6. All male and female patients with child-bearing potential (between puberty and 2 years after menopause) should use at least any one of the appropriate contraception methods shown below, for during and at least 4 weeks after ceftriaxone treatment. 1. Total abstinence (when this is in line with the preferred and usual lifestyle of the subject. Periodic abstinence (e.g., calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception). 2. Female sterilization (have had surgical bilateral oophorectomy with or without hysterectomy) or tubal ligation at least six weeks before taking study treatment. In case of oophorectomy alone, only when the reproductive status of the woman has been confirmed by follow up hormone level assessment. 3. Male sterilization (at least 6 months prior to screening). For female subjects on the study, the vasectomized male partner should be the sole partner for that subject 4. Combination of any two of the following listed methods: (d.1+d.2 or d.1+d.3, or d.2+d.3): d.1 Use of oral, injected or implanted hormonal methods of contraception or other forms of hormonal contraception that have comparable efficacy (failure rate \