Recruiting
Phase 1
Phase 2

Acetazolamide

Sponsor:

Vishwajit Nimgaonkar, MD PhD

Code:

NCT04887792

Conditions

Schizophrenia

Schizo Affective Disorder

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Not accepted

Interventions

Acetazolamide

Placebo

Study Details

Brief summary:

This is a double blind adjunctive randomized controlled trial for schizophrenia using acetazolamide.

Conditions

Schizophrenia

Schizo Affective Disorder

Study ID

NCT04887792

Start date

Feb 1, 2022

Status verified date

Jul, 2026

Completion date

Jun 30, 2028

Anticipated

Primary completion date

Dec 30, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Written informed consent.
  • Both genders, ages 18-55 years (older patients may not tolerate high ACZ dose).
  • PANSS total score > 60 and Score > 4 on one or more items of the 'positive' syndrome items (P1-P7), following treatment at therapeutic doses for 6 weeks with different APDs on 2 occasions.
  • Stable dose of antipsychotic drug (APD) for > 1 month, continued throughout the study.
  • Not participating in another randomized controlled clinical trial (RCT).

Exclusion Criteria:

  • Substance abuse in the past month/dependence past 6 months with the exception of methadone prescribed for opiate withdrawal.
  • History or current medical/neurological illnesses that may lead to unstable course, e.g., epilepsy.
  • Pregnancy.
  • Acetazolamide (ACZ) contraindications: hypersensitivity to ACZ; history of renal hyperchloremic acidosis; Addison's disease/adrenal failure; chronic closed angle-closure glaucoma.
  • Current or prior treatment with ACZ or history of hypersensitivity to ACZ.
  • Intellectual disability as defined in DSM 5.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: Acetazolamide

acetazolamide capsules

active comparator: Placebo

Identical gelatin capsules

Interventions

Acetazolamide

ACZ 250 mg/day in gelatin capsules will be administered initially and increased over 7-10 days to 2g/day.

Placebo

Identical gelatin capsules will be prepared by filling with inert excipients.

Primary outcome measure

  • Change in positive symptoms [ Time Frame: 24 weeks ]

Central Contacts and Locations

Central contacts

Vishwajit L Nimgaonkar, M.D., Ph.D.

412-246-6356vishwajitNL@upmc.edu

Maribeth A Wesesky, BPS

4122957017weseskyma@upmc.edu

Locations

University of Pittsburgh

Recruiting

Pittsburgh, Pennsylvania, United States, 15213

Contacts

Maribeth A Wesesky, BPS

412-295-7017weseskyma@upmc.edu

More Information

Sponsor

Vishwajit Nimgaonkar, MD PhD

Last update posted

Jul 7, 2026

Last verified

Jul, 2026

Keywords

  • Schizophrenia
  • Schizo Affective Disorder
  • acetazolamide

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Vishwajit Nimgaonkar, MD PhD on 2026-07-07.