Project details

Summary

What is the study about?

Like all medicines clozapine can cause side-effects and the side-effect we are interested in is where patients produce too much saliva (spit). Doctors call this ‘clozapine-induced hypersalivation’ (CIH or drooling). People who take clozapine tell us that this is one of the most upsetting side effects of clozapine.

What are you trying to find out?

This study will find out if either hyoscine (Kwells) or glycopyrronium bromide (glycopyrrolate) can improve CIH/drooling by comparing patients taking these medications with patients taking a dummy treatment (placebo). If hyoscine and glycopyrrolate both help reduce CIH/drooling, we will compare the two medications to see which one causes fewer side effects and ask patients which one they prefer. This will help doctors and patients to choose the most effective medication for CIH/drooling.

We want 252 patients (both men and women) to take part in the GOTHIC2 study. 84 patients will receive hyoscine, 84 patients will receive glycopyrrolate and 84 patients will receive a ‘dummy’ treatment (placebo).

What does taking part involve?

Your participation in the study will last for 12 weeks: for the first 48 hours, you will be asked to stop taking your current CIH/drooling medication (if you have one).

The study medication you receive will be decided by chance (like the flip of a coin) to receive either:

• A medicine called hyoscine hydrobromide (Kwells)
• A medicine called glycopyrronium bromide (glycopyrrolate)
• A placebo (dummy capsule, no active medication)

You will have a 1 in 3 chance of having one of these. For the following 12 weeks, you will be asked to take your study medication, but you will not be told which medication it is.

You will continue to take your clozapine as normal throughout the study. During the study, you will be visited by a researcher on four occasions and telephoned three times. On each occasion, the researcher will ask you to complete a number of different tasks.

Who is it for?

We are looking for people to take part in our study who: 

• have been prescribed clozapine for a minimum of 12 weeks
• are experiencing drooling because of clozapine
• are aged between 18 and 65 years
• speak English
• are able to provide informed consent. 

Why is it important? 

We do not know whether the medicine you are given will have any benefits, but we hope that the information we gain from this study will help us to improve treatment for patients who suffer from producing too much saliva because of taking clozapine. 

How can I find out more?

You can find out more information about taking part in this study by downloading the key documents at the top of this page. You can also visit the project website here. 

If you are interested in taking part in this study, or have questions for the research team, click the button below to email the research team:

Email the research team