A Phase 4 interventional study of Cabergoline (Dopamine Agonist) in Prolactinoma, sponsored by University Hospital, Basel, Switzerland. Recruiting at 1 site in Switzerland. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-09-23.
Sponsored by University Hospital, Basel, Switzerland · Phase 4, Interventional, and Treatment
This randomized, active-controlled, parallel-arm, single-blind trial is to compare the effects of Dopamine agonists (DA) therapy targeting different established treatment strategies on glucose metabolism assessed by an oral glucose tolerance test.
Prolactinomas are the most common pituitary tumors, leading to hyperprolactinemia, which causes hypogonadism, infertility, and is associated with adverse metabolic effects such as insulin resistance, dyslipidemia, and obesity. Dopamine agonists (DAs), especially cabergoline, are the first-line treatment. They reduce prolactin levels and tumor size effectively. Despite their widespread use, there are no evidence-based guidelines regarding target prolactin levels during DA therapy. Limited evidence suggests that different prolactin levels may have different effects on metabolic health. This trial aims to assess glucose tolerance, insulin sensitivity, and beta-cell function-using OGTT with insulin levels-after 12 months of DA treatment, to target treatment options.
In Switzerland, cabergoline is the preferred DAs for treating hyperprolactinemia.
Cabergoline is available in tablet form, with doses of 0.5 mg per tablet. The standard dosing for hyperprolactinemia typically starts at 0.25 mg to 0.5 mg per week, which can be gradually increased based on the patient's response, with a usual range of 0.25 mg to 2 mg per week.
28 studies on the registry are indexed under Prolactinoma; 5 are open to participants now.
This study's planned enrollment of 60 is close to the median of 55 across 14 interventional studies indexed under Prolactinoma.
Browse Prolactinoma studies →University Hospital, Basel, Switzerland is the lead sponsor of 990 studies on the registry; 189 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria (treatment-naïve patients):
Inclusion Criteria (treatment-naïve patients):
Exclusion Criteria:
Severe hepatic insufficiency or cholestasis
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Child-Pugh class
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The experimental intervention arm aims to treat patients (with hyperprolactinemia) with Cabergoline (Dopamine Agonist) by targeting the suppression of prolactin levels (below the normal plasma prolactin range).
Drug: Cabergoline (Dopamine Agonist)
The control intervention arm aims to treat patients (with hyperprolactinemia ) with Cabergoline (Dopamine Agonist) by targeting the normalisation of prolactin levels (within the normal plasma prolactin range).
Drug: Cabergoline (Dopamine Agonist)
Cabergoline is available in tablet form, with doses of 0.5 mg per tablet. The standard dosing for hyperprolactinemia typically starts at 0.25 mg to 0.5 mg per week, which can be gradually increased based on the patient's response, with a usual range of 0.25 mg to 2 mg per week. The dose required to achieve the target prolactin levels (pre- defined for each intervention arm) may vary between patients, so a fixed dose is not specified. This allows for individualized treatment based on each patient's response.
2-hour post-oral glucose tolerance test (OGTT) plasma glucose levels
The OGTT is a test used to assess the ability to process glucose. It involves fasting overnight and then drinking a solution containing a measured amount of glucose (75g). Blood Samples are taken at 120 min after glucose intake.
Time frame: assessed at 12 months after randomisation
Change in Insulin sensitivity by MATSUDA Index
The Matsuda Index is a measure used to assess insulin sensitivity from the data obtained during an OGTT. The Index is derived from OGTT data and reflects whole-body insulin sensitivity by incorporating both fasting and postprandial glucose and insulin levels. The formula uses (1) fasting glucose and insulin before the glucose load and (2) mean glucose and mean insulin.
Time frame: measured at time points (0, 30, 60, 90, and 120 minutes) during the OGTT
Change in Insulin Sensitivity Index (ISI)
ISI is an OGTT-based measure that quantifies insulin sensitivity using fasting and post-load insulin and glucose values. It is similar to the Matsuda Index but has variations depending on specific formulas. Higher ISI values reflect better insulin action.
Time frame: measured at time points (0, 30, 60, 90, and 120 minutes) during the OGTT
Change in Quantitative Insulin Sensitivity Check Index (QUICKI)
QUICKI is a simple, fasting- based index to estimate insulin sensitivity, calculated as 1 / (log(Fasting Insulin) + log(Fasting Glucose)). Higher values indicate greater insulin sensitivity.
Time frame: measured at time points Screening, Month 6, Month 12, Month 24
Change in Glycated Haemoglobin (HbA1c)
HbA1c reflects average blood glucose levels over the past 2-3 months by measuring glucose-bound haemoglobin. It is used for diagnosing and monitoring diabetes, with values ≥6.5% indicating diabetes.
Time frame: measured at time points Screening, Month 3, Month 6, Month 12
Change in Fasting glucose (mmol/L)
Fasting glucose measures baseline blood sugar levels after at least 8 hours of fasting. It is a primary diagnostic criterion for diabetes, with ≥7.0 mmol/L indicating diabetes.
Time frame: measured at time points Screening, Month 3, Month 6, Month 12
Change in Fasting insulin (µU/mL)
Fasting insulin provides insight into pancreatic insulin secretion and insulin resistance. Elevated levels often indicate insulin resistance, while low levels may suggest beta-cell dysfunction.
Time frame: measured at time points Screening, Month 3, Month 6, Month 12
Change in C-peptide (nmol/l)
C-peptide is released in equal amounts to insulin and is used to assess endogenous insulin production
Time frame: measured at time points Screening, Month 3, Month 6, Month 12
Change in Disposition Index (DI)
The DI integrates beta-cell function and insulin sensitivity, calculated as insulin secretion × insulin sensitivity. It reflects how well beta-cells compensate for insulin resistance, with lower values indicating a higher risk of diabetes.
Time frame: measured at time points Screening, Month 3, Month 6, Month 12
Change in plasma prolactin levels (ng/mL)
Change in plasma prolactin levels (ng/mL)
Time frame: measured at time points Screening, Month 3, Month 6, Month 12
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