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(▼) The medicinal product is subject to additional monitoring, the notification of suspicious adverse reactions related to it is a priority.

Molecule develoved in under a R&D model of public and private sectors Autonomous University of Madrid, CSIC and Ferrer Group.

Diagnosis drug LacTEST® represents a noninvasive method based on oral administration of 4-galactosil-xilose (4-O-β-D galactopiranosil-D-xilose) whose INN is Gaxilose, for hypolactasia diagnosis.

This synthetic disaccharide, a substrate of intestinal lactase is hydrolyzed and the result is 2 physiological products: galactose and xylose. Galactose is converted into glucose in the liver and xylose is absorbed from a passive way and partially metabolized endogenously (50%). The rest appears in blood and it is excreted finally through urine. The amount of xylose in urine is proportional to the activity of intestinal lactase. This represents a direct measure of hypo or normo lactasia.

Low levels of xylose in urine are related to a low lactase activity. In the following chart Gaxilose structure and products after hydrolyzing can be observed as well as the process of xylose in our body.


Detailed information on safety of this medicinal product is available on the Summary of Product Characteristics.

LacTEST® 0, 45 g powder for oral solution is a drug indicated to the diagnosis of hypolactasia in adults and elderly patients presenting clinical symptoms of lactose intolerance.

Method of administration is based on oral consumption of a structural analogue of lactose (Gaxilose) that breaks into galactose and xylose. Xylose can be detected in urine. The amount of xylose detected in urine is proportional to the level of intestinal lactase activity. This method allows making a direct measure of xylose.

Based on the result, physicians can make some recommendations to the patients about the ingestion or not of dairy products once the test has been performed.

To evaluate safety, efficiency and superiority of Gaxilose test with regard to those already existed; a complete program of preclinical and clinic development have been made following the applicable regulations for diagnosis drugs.

Three clinical trials have been carried out to evaluate the efficiency and safety of LacTEST® to the diagnosis of deficiency of intestinal lactase or the two first clinical trials, Phase I y Phase Ib, method of 4-galactosil-xylose o Gaxilose was evaluated in urine and blood in healthy volunteers and there is also a third clinical trial (Phase IIb/III) made with patients with clinical symptoms suggesting lactose intolerance.