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Completed

NCT Number: NCT02398279

L-arginine add-on Therapy in Patients With Schizophrenia

This study evaluates the addition of L-Arginine to the usual regimen in the treatment of schizophrenia in adults. As a requisite of crossover design, half of the participants started with L-Arginine and the other half with placebo and switched over after a three weeks use and one week of a washout period.

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Key information

Conditions

Schizophrenia Mental Disorders Psychotic Disorders Schizoaffective Disorder Schizophrenia Spectrum and Other Psychotic Disorders

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Hacettepe University Faculty of Medicine Department of Psychiatry

Ankara, 06100, Turkey (Türkiye)

About this study

L-arginine is the precursor of nitric oxide (NO), a neuromodulator of dopamine, gamma-aminobutyrate (GABA) and glutamate systems. Nitric oxide donors which increase NO levels at the cellular level could improve N-methyl-D-aspartate (NMDA) receptor dysfunction. Using L-arginine could bypass the blocked NMDA receptors and improve the therapeutic efficacy by reversing the dysfunction.

The investigators proposed that using L-Arginine, a dietary supplement in most cultures, might constitute a safe option as an add-on treatment which may display beneficial effects on positive, negative, cognitive and affective symptoms associated with schizophrenia.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Schizophrenia-Schizoaffective Disorder
  • Clinical Global Impression >4
  • Able to take oral medication and likely to comply the required evaluations
  • On stable medication regimen for 8 weeks
  • Competent and willing to give informed consent

Exclusion criteria

  • Uncontrolled medical illness (renal disease, hepatic, cardiac diseases, gout, asthma, diabetes, sickle cell anemia, low-high blood pressure)
  • History of Myocardial Infarction (MI)
  • History of genital herpes infections/ receiving lysine containing treatments
  • Pregnancy/ lactation
  • Substance related and Addictive Disorders
  • Drugs that might induce hypotension
  • Intolerance to L-arginine and ingredients of placebo or L-arginine capsule

Treatment and study plan

L-Arginine

Dietary Supplement

Experimental supplement

Placebo

Other

Placebo capsules in the same color and shape with the experimental supplement

Primary outcomes

  1. Change from baseline in Positive and Negative Syndrome Scale

    Time frame: baseline and week 3

    Evaluating change in Positive and Negative Syndrome Scale between baseline and Week 3, comparing subjects treated with L-Arginine for 3 weeks to subjects treated with placebo for 3 weeks.

Secondary outcomes

  1. Change from baseline in Neuropsychological Test Battery

    Time frame: baseline and week 3

    Evaluating change in Neuropsychological Test Battery between baseline and Week 3, comparing subjects treated with L-Arginine for 3 weeks to subjects treated with placebo for 3 weeks.

  2. Change from baseline in the The Calgary Depression Scale for Schizophrenia

    Time frame: baseline and week 3

    Evaluating change in The Calgary Depression Scale for Schizophrenia between baseline and Week 3, comparing subjects treated with L-Arginine for 3 weeks to subjects treated with placebo for 3 weeks.

  3. Change from baseline in Clinical Global Impression - Severity

    Time frame: baseline and week 3

    Evaluating change in Clinical Global Impression - Severity between baseline and Week 3, comparing subjects treated with L-Arginine for 3 weeks to subjects treated with placebo for 3 weeks.

  4. Change from baseline in Abnormal Involuntary Movement Scale

    Time frame: baseline and week 3

    Evaluating change in Abnormal Involuntary Movement Scale between baseline and Week 3, comparing subjects treated with L-Arginine for 3 weeks to subjects treated with placebo for 3 weeks.

  5. Change from baseline in Uku Side Effects Rating Scale

    Time frame: baseline and week 3

    Evaluating change in Uku Side Effects Rating Scale between baseline and Week 3, comparing subjects treated with L-Arginine for 3 weeks to subjects treated with placebo for 3 weeks.

  6. Change from baseline in blood pressure

    Time frame: baseline and week 7

  7. Change from baseline in heart rate

    Time frame: baseline and week 7

  8. Change from baseline in temperature

    Time frame: baseline and week 7

  9. Change from baseline in respiratory rate

    Time frame: baseline and week 7

  10. Change from baseline in weight

    Time frame: baseline and week 7

  11. Change from baseline in electrocardiogram

    Time frame: baseline and week 7

  12. Change from baseline in complete blood count

    Time frame: baseline and week 7

    Composed of different measures. Change in any measure indicates impairment in the composite measure

  13. Change from baseline in alanine aminotransferase

    Time frame: baseline and week 7

  14. Change from baseline in aspartate aminotransferase

    Time frame: baseline and week 7

  15. Change from baseline in alkaline phosphatase

    Time frame: baseline and week 7

  16. Change from baseline in urea

    Time frame: baseline and week 7

  17. Change from baseline in creatinine

    Time frame: baseline and week 7

  18. Change from baseline in sodium

    Time frame: baseline and week 7

  19. Change from baseline in potassium

    Time frame: baseline and week 7

  20. Change from baseline in chloride

    Time frame: baseline and week 7

  21. Change from baseline in calcium

    Time frame: baseline and week 7

  22. Change from baseline in thyroid-stimulating hormone

    Time frame: baseline and week 7

  23. Change from baseline in free T4

    Time frame: baseline and week 7

  24. Change from baseline in total cholesterol

    Time frame: baseline and week 7

  25. Change from baseline in HDL

    Time frame: baseline and week 7

  26. Change from baseline in LDL

    Time frame: baseline and week 7

  27. Change from baseline in triglycerides

    Time frame: baseline and week 7

  28. Change from baseline in human chorionic gonadotropin

    Time frame: baseline and week 7

    Pregnancy test in women

Sponsors and collaborators

Lead sponsor

Hacettepe University

Other

Registry information

Official study title

L-Arginine add-on Treatment for Schizophrenia: A Randomized, Double Blind, Placebo Controlled, Cross Over Study

Important dates

Study start
2011
Primary completion
2012
Study completion
2013
First posted
Mar 25, 2015
Registry last updated
Mar 25, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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