A trial looking at how drugs are broken down in the body when people have bladder cancer (Pittsburgh study)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Bladder cancer





This trial is looking at how certain enzymes Open a glossary item break down drugs in the body. The research team will be comparing the enzyme activity in those with bladder cancer and those without.

Some drugs are broken down in the body by enzymes. Enzymes are proteins that control chemical reactions. The research team think that enzyme activity is different in people with bladder cancer compared to those without bladder cancer. If this trial shows that people with bladder cancer break down drugs in a different way, this could affect future research.

People in this trial will have a low dose of 4 different drugs to see what happens to certain enzymes in the body. The research team want to see if there is a link between enzyme activity and bladder cancer. The drugs used in this trial are not treatments for bladder cancer.

The aim of this trial is to find out if enzyme activity is different in people with bladder cancer and people without. And to find out more about whether this enzyme activity is related to how well people with bladder cancer respond to treatment.

Who can enter

You can take part if you have been seen at an outpatient clinic at Bristol Royal Infirmary or Southmead Hospital in Bristol because you have had blood in your urine.

You cannot enter this trial if you

  • Have had an allergic reaction to any of the drugs used in this trial
  • Have cirrhosis of the liver
  • Have poor kidney function
  • Are pregnant

As part of this trial you will need to stop taking most other drugs for 2 days (there are some exceptions). If you are taking any drugs that affect the enzymes studied in this trial and you can’t stop taking them for 2 days, you won’t be able to take part. Your doctor will be able to tell you if this is the case. Please do not stop taking any of your medications unless you are told to do so by your doctor.

Trial design

This trial will recruit 250 people from the outpatient clinics in Bristol. This will be 125 people who have bladder cancer and 125 people who don’t. The people who don’t have bladder cancer will be the ‘control group’ in the trial.

Everyone in this trial will have 4 different drugs. They are all licensed drugs but are not treatments for bladder cancer. You will take one low dose of each of the following

  • Caffeine - equivalent to about 1 to 2 cups of coffee
  • Metoprolol (Betolac, Lopresor) - use to treat heart problems such as high blood pressure, angina and heart failure
  • Chlorzoxazone - used to treat muscle spasms and pain
  • Dapsone - used to treat skin disorders

The research team will ask you a number of questions about your home and work environment. This is to find out if you have been exposed to any known risk factors for bladder cancer.

Hospital visits

You will have a cystoscopy as one of the tests to find out what is causing the blood in your urine. The doctors will take a sample (biopsy) of any areas of the inside of your bladder that look abnormal. If the test results show that you have bladder cancer, the research team will look at the tissue samples in more detail.

You will need to avoid alcohol and caffeine for 2 days before you take the drugs as part of this trial. You may also have to stop taking some of your regular medication, but your doctor will tell you more about this.

You have a blood test and a urine test before you have the drugs. The research team will collect your urine for 8 hours after you have taken the 4 drugs. And take a blood sample at 4 hours and 8 hours. They will use these to look at the activity of enzymes in your body.

You will be at the hospital for about 8 hours on the day you have the drugs. But you shouldn’t have to stay in overnight.

If you have bladder cancer, you will see the doctors regularly as part of your routine care. If you don’t have bladder cancer you won’t need to see the trial team again.

Side effects

The drugs used in this trial all have some side effects when taken at full dose. But you will have a single low dose, so the research team are not expecting you to have any side effects. The most common side effects of the full dose include

  • Caffeine - feeling restless or having an increased heart rate
  • Metoprolol - possible drop in blood pressure and dizziness when standing up in the first hour or so
  • Chlorzoxazone - feeling drowsy, dizzy or light headed, but these are rare
  • Dapsone - there are no side effects with a single dose

There are other, rare, side effects. Your doctor will tell you about these in more detail. As with all treatments, there is a risk that there are other side effects we don’t know about yet.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Dr Robert A Branch (Chief Investigator in US)
Dr Raj Persad (Principal Investigator in the UK)

Supported by

NIHR Clinical Research Network: Cancer
United Bristol Healthcare NHS Trust
University of Pittsburgh

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle - 690

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Over 60,000 cancer patients enrolled on clinical trials in the UK last year.

Last reviewed:

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