GOTHIC 2: A multi-centre randomised placebo-controlled trial of Glycopyrrolate and Hyoscine Hydrobromide for the treatment of clozapine-Induced hypersalivation
Overview
HELP IMPROVE TREATMENT FOR CLOZAPINE-INDUCED HYPERSALIVATION
Do you have drooling because of taking clozapine?Joining our clinical trial could contribute to developing better treatment for this distressing condition.
Can you help?
We invite women and men who are affected by drooling because of clozapine to take part in a 12-week trial of medication (this could be either hyoscine, glycopyrrolate
or a dummy tablet). Your help will contribute to better evidence for an effective treatment for drooling.
Are you interested in taking part in this study?
Planned end date
01 Oct 2026 10:37Conditions
SchizophreniaInclusion Criteria
1. Aged 18 to 65 years inclusive.
2. English speaking.
3. Prescribed clozapine for a minimum of three months.
4. Experiencing hypersalivation with a minimum score of 4 on the Drooling Rating Scale (DRS) and are either:
(a) Currently not receiving treatment for CIH
OR
(b) Receiving drug treatment for CIH and agreeable to a 48-hour washout period
5. Written and informed consent obtained from participant (with capacity and ability) and agreement of participant to comply with the requirements of the trial prior to study specific procedures.
Exclusion Criteria
1. Medical conditions that could influence hypersalivation (e.g., Parkinson’s Disease).
2. Neurological conditions that could affect cognitive functioning during the course of the study (e.g., unstable epilepsy).
3. History of an allergic reaction to hyoscine hydrobromide
4. History of an allergic reaction to glycopyrrolate.
5. Any of the following contra-indications to hyoscine hydrobromide or glycopyrrolate as stated in the British National Formulary:
(a) Prostatic enlargement
(b) Myasthenia gravis
(c) Pyloric stenosis
(d) Paralytic ileus
(e) Glaucoma
(f) Hepatic Impairment
6. Any of the following cautions to hyoscine hydrobromide or glycopyrrolate as stated in the British National Formulary:
(a) Chronic heart failure
(b) Stomach ulcer
(c) Ulcerative colitis
(d) Significant liver disease that in the opinion of the CI or PI is a contraindication
(e) Down’s syndrome
(f) Arrythmia and/or history of myocardial infarction
(g) Overactive thyroid gland.
(h) Unstable angina
7. Current prescription for a) potassium chloride, b) digoxin, c) amantadine, or d) levodopa.
8. Pregnant, trying to conceive or breastfeeding.
9. Patients who are unable or unwilling to use contraception during the study or abstain from sexual intercourse (see section 10.4).
10. Participation in another drug study within the preceding 12 weeks or use of other investigational drugs.
11. Active suicidal ideation as assessed within usual care.
12. Known sensitivity to any interventions or excipients.
13. Known history of intestinal obstruction.
14. Known history of urinary retention.
15. Severe renal impairment (eGFR <30 ml/min/1.73m2).
16. Known history of brain tumour or encephalitis.