An active component in the tablet Cardura XL is doxazosine. Doxazosine belongs to the third generation of alpha 1-adrenolytics. It is a blocker of post-synaptic alpha 1-receptors both in humans and in animals. It is a long acting preparation. A tablet cover of Cardura XL is built of two layers (GITS system). It has enabled administration of doxazosine once a day. A great advance of the GITS system is a verly slow and systematic release of the drug from the tablet. This release is independent of pH of gastro-intestinal content or peristalsis. After administration of the tablet of Cardura XL, over 85% of the drug is released after 12 hours and the release ends after 12-16 hours. Maximal serum drug level after administration of doxazosine GITS is observed after 14-16 hours. Higher maximal serum drug level is achieved when the drug is administered together with a meal. Using doxazosine in the GITS form, minimal and maximal serum drug levels during the whole 24 hours differ non significantly. GITS technology enabled achieving stable daily serum drug concentration. Introducing doxazosine GITS caused: 1. decrease of Cmax; 2. elongation of Tmax; and 3. decrease of Cmin compared to doxazosine. It became possible due to gradual absorption of the preparation from gastrointestinal tract and improved coefficient of the drug fluctuation. It should be stated that the described pharmacological differences of doxazosine GITS in younger and elderly, in female and male patients do not influence significantly initial dosing of the drug. Stenosis of the gastrointestinal tract or chronic diarrhea affecting bowel passage of the drug, change its therapeutic effect. An effect of doxazosine GITS, doxazosine and placebo on blood pressure was studied in 392 patients with mild and moderate hypertension (< or = 220/95-115 mm Hg). Doxazosine GITS similarly to doxazosine effectively decreases blood pressure. The value of diastolic blood pressure decrease increases together with the therapy duration. Use of the unique GITS technology assures stable daily serum drug concentration. It results in: mild but permanent decrease of the blood pressure, decreased risk of side-effects, including orthostatic hypotony. Based on the performed post-registration studies it should be stated that doxazosine GITS is not only a very effective but also a safe preparation, which may be administered once daily. The treatment should be initialized with a dose of 4 mg daily. In as much as 60% of the patients with mild or moderate arterial hypertension, an initial dose (4 mg of Cardura XL) effectively lowers blood pressure. Taking into consideration unique features of the described preparation, it is worth thinking of Cardura XL while initializing or switching therapy in hypertensive patients. Cardura XL, due to favourable metabolic effects as well as the unique GITS technology seems to be the drug particularly suitable in hypertensive patients with accompanying dyslipidaemia, diabetes mellitus type 2 and/or benign prostata hypertrophy.