Study to determine the efficacy and safety of Antistax® film coated tablets in improving microcirculation of the skin in the leg of patients with chronic venous insufficiency (CVI)

Inclusion Criteria:

• Male or female
• >= 18 years of age
• CVI I or CVI II (without expanded trophic disturbances)
• Willing and able to give written informed consent in accordance to Good Clinical Practice and local legislation prior to participation in the study

Exclusion Criteria:

Concomitant disease(s) exclusion criteria:

• Decompensated cardiac insufficiency
• Edema not due to venous disease of the legs (e.g. latent cardiac insufficiency, renal insufficiency, lymph edema, etc)
• Peripheral arterial disease (ankle/arm pressure index < 0.9)
• Current acute phlebitis or thrombosis
• Renal insufficiency (Serum creatinine > 1.5 mg/dl)
• Liver disease (SGPT (ALAT) > 3x upper limit of normal)
• Other diseases: insulin-dependent diabetes mellitus, neuropathies, hyper- or hypocalcaemia, malignancies
• Anamnestic indications of diabetic microangiopathy or polyneuropathy
• Drug and/or alcohol abuse
• Pregnant or nursing women or inadequate birth control methods (this applies to females of childbearing potential only)
• Severe climacteric complaints or changes in, or initiation with post-menopausal hormone replacement therapy within the last 3 months
• Immobility
• Avalvulie
• Klippel-Trénaunay-Weber-Syndrome (Naevus varicosis osteohypertrophicus, Haemangiectasia hypertrophicans)
• State after pulmonary embolism
• Recognized hypersensitivity to the trial drug ingredients
• Current florid venous ulcus
• Clinical indication for a necessary, specific phlebologic acute treatment, e.g. compressive treatment, phlebectomy, etc.

Previous treatment(s) exclusion criteria:

• Treatment with venous drugs within the last 4 weeks
• Changes in, or initiation with, treatment with theophylline, diuretics, cardiac glycosides, ACE inhibitors or calcium antagonists within the last 8 days

Concomitant treatment/non-drug therapy exclusion criteria:

• Other venous drugs apart from the trial medication
• Compression bandages
• Venous surgery of the leg used for the fluxmetry
• Extensive use (i.e. on more than a total of 6 days during the entire trial) of laxatives which affect fluid or electrolyte balance
• Major surgery requiring full anesthesia

Other exclusion criteria:

• Previously studied under this protocol
• Participation in another clinical trial within the previous 90 days or during the present study
• Patients considered as mentally ill as well as unable to work or with limited working ability, or unable (or only partially able) to follow the spoken or written explanations concerning the trial
• Patients in a bad general health state according to the investigator's judgment