The goal of this observational study is to examine the interaction between the diuretic furosemide and certain toxins called protein-bound uremic toxins (PBUTs) in patients with chronic kidney disease (CKD). The main question it aims to answer is: what is the effect of furosemide on plasma levels of PBUTs in patients with CKD? Besides, the investigators will also look at the effect of furosemide on the excretion of PBUTs via the urine.
Participants will be included in the study once they will be prescribed furosemide as part of routine patient care. Before they start with the furosemide treatment, patients will undergo the following:
* Blood pressure measurement * Blood sample withdrawal * Urine sample collection * 12-hour urine collection
Then, one to four weeks after starting with furosemide treatment, patients will undergo the following:
* Blood pressure measurement * Blood sample prior to furosemide intake (Tmin) * Blood sample withdrawal 90 minutes after furosemide intake (Tmax: time at which the highest furosemide plasma level is expected) * Urine sample collection 60-120 minutes after furosemide intake * 12-hour urine collection
The investigators expect furosemide to increase plasma levels of PBUTs by decreasing the renal excretion of the toxins.
An age of 18 years or older
An eGFR <60 mL/min/1.73m2 for at least three months (diagnosis of CKD stage 3-5)
An indication for the start of treatment with furosemide as part of routine patient care
Willingness to participate in the study and a signed informed consent
Patients who are already on furosemide treatment
Patients with a liver disease with hyperbilirubinemia
Patients who receive any type of renal replacement therapy (peritoneal dialysis, haemodialysis)
Patients with end-stage renal failure without residual diuresis
UMC Utrecht
Lead sponsor
Maastricht University, MERLN Institute for Technology-Inspired Regenerative Medicine
Collaborator
Utrecht Institute for Pharmaceutical Sciences
Collaborator