RecruitingPhase 4ACTRN12617001547336

The efficacy of Metformin as an adjunctive treatment to attenuate weight gain and metabolic syndrome in patients with schizophrenia or schizoaffective disorder newly commenced on clozapine

Sponsor

The University of Queensland

Enrollment

86 participants

Start Date

Mar 5, 2018

Study Type

Interventional

Conditions

Schizophrenia

Summary

The study will be a randomised, placebo-controlled, double-blind parallelgroup trial over a 24 week period. The primary objective is to examine the clinical efficacy of the add-on treatment of Metformin XR for people newly commenced on clozapine. Specifically, it is hypothesised, that participants allocated to the active arm (2000mg once daily) Metformin XR will have lower mean body weight at week 24 compared to individuals taking placebo, adjusted for baseline body weight (ANCOVA).

Eligibility

Sex: Both males and femalesMin Age: 18 YearssMax Age: 64 Yearss

Inclusion Criteria6

Aged between 18 and 64 years (inclusive)
Fulfil the DSM-IV criteria practice for schizophrenia or schizoaffective disorder, based on the Diagnostic Interview for Psychosis (DIP)
Have received oral clozapine for a period of no more than 2 weeks
Agree to participate, have capacity to consent and are able to follow the study instructions and procedures
Fasting Blood Glucose Level less than or equal to 5.6 mmols (confirmed within the previous two weeks of commencing clozapine)
BMI greater than or equal to 18 and less than or equal to 40

Exclusion Criteria11

Known allergies to Metformin or any part of the formulation of the investigational product
Obesity induced by other endocrinologic disorder (e.g Cushing Syndrome, untreated
Hypothyroidism)
Current use of any weight-lowering therapy including: pramlintide, sibutramine, orlistat, zonisamide, topiramate or phenteremine (either by prescription or as part of a clinical trial)
Diagnosis of Type 1 or Type 2 Diabetes mellitus or already on metformin
Participants treated with corticosteroids or other hormone therapy (except oestrogens or thyroxine) for greater than 10 days
Chronic kidney disease (eGFR<60mL/min)
Previous surgical treatment of obesity
BMI less than or equal to 18 or BMI greater than or equal to 40
Any concomitant disease or condition that according to the investigator’s assessment makes the patients unsuitable for trial participation
People who are unable to understand or communicate in English

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Interventions

The study will include 86 individuals with schizophrenia or schizoaffective disorder who will be randomised to receive either 2g/d (2000 mg once daily) of Metformin XR tablet or placebo (1:1 ratio)

The study will include 86 individuals with schizophrenia or schizoaffective disorder who will be randomised to receive either 2g/d (2000 mg once daily) of Metformin XR tablet or placebo (1:1 ratio) orally for 24 weeks, in addition to their normal routine care. Participants will be requested to return all unused study medication (i.e. unopened bottles or tablets not taken) and empty bottles to the delegated research assistants. All unused supplies of study medication will be accounted for and documented by the designated Research Pharmacist. Compliance with study medication will be calculated at each visit by means of self-report and a tablet count. Face to face clinical assessments will be weekly for the first 4 weeks and then monthly (4, 8, 12, 16, 20, 24) for the duration of the study.