Iotalamate meglumine

What is iotalamate meglumine?

Iotalamate meglumine is a contrast agent used in diagnostic tests. In the registered trial it appears as iotalamate meglumine given by intravenous infusion, and also as a radioactive form called sodium iotalamate (125I) given by intravenous bolus injection or infusion.^[1] The substance is used to measure glomerular filtration rate (GFR), which shows how well the kidneys filter waste from the blood.

How does iotalamate meglumine work?

Iotalamate meglumine works as a filtration marker. When injected into the bloodstream, it is cleared from the blood almost entirely by the kidneys through glomerular filtration. By measuring how quickly the substance disappears from the blood or appears in the urine, doctors can calculate the glomerular filtration rate.^[1] The trial compares a radioactive version, 125I-iothalamate, with a non-radioactive method using iohexol, another filtration marker.

Which conditions is it used or studied for?

• Chronic kidney disease — a long-term condition in which the kidneys gradually lose their ability to filter blood.
• Kidney failure — the most severe stage of kidney disease, when the kidneys can no longer maintain the body's balance of fluids and waste products.

Both conditions are the focus of the registered Phase 3 trial.^[1]

How is iotalamate meglumine given?

In the registered trial, iotalamate meglumine is given as an intravenous infusion of 150 millilitres. The radioactive form, sodium iotalamate (125I), is given as an intravenous bolus injection or infusion of 3.7 megabecquerels.^[1] Other substances used in the same study include aminohippuric acid, adrenaline, omnipaque and tavegyl, each with its own route of administration.

What do the clinical trials show?

One Phase 3 interventional trial is registered for iotalamate meglumine. It plans to enrol 200 participants and has the status Authorised.^[1] The trial is designed to determine whether the glomerular filtration rate measured with radioactive 125I-iothalamate and 131I-hippuran is equivalent to the rate measured with non-radioactive iohexol. The primary outcome is the measured glomerular filtration rate (mGFR) determined by both methods.^[1]

The study includes people with chronic kidney disease and kidney failure. Participants receive several substances by different routes, including intravenous, subcutaneous, intramuscular and oral administration, as part of the validation procedure.^[1]

What side effects are known?

The registry record for this trial does not list side effects. No supplementary safety information is available in the data provided.