In order to evaluate the biological effects on some haemostasis factors of antithrombotic-hemorheological treatments on patients with vascular dementia, a multicenter, randomized, double-blind,double-dummy,study comparing sulodexide (Sdx, 50 mg bid orallyfor 6 months)and pentoxitjd]ine (Ptx, 400 mg tid orallyfor six months) was carried out. Eighty-six patients, 46 in Sdx group, 40 in Ptx group, fidfilling the NINDS-AIREN criteriafor probablevascular dementiawere evaluated. Plasmafibrinogenlevelsshoweda significant reductionin both groups, in patientswith highbasal levels(2350 mg/dl),the reductionbeingearlierin Sdx group (2nd month of therapy)than in Ptx group (4th monthof therapy).In Sdx group a significantreduction in factor VII-Ag (baseline102.8U/all;6th month 90.1 U/all)was also observed.Both drugs induced a slight reduction in activated factor VII levels as well. A parallel improvementof G.B.S. Rating Scale for dementiascores was observed in Sdx group. These results seem to indicatethat sulodexidetreatment can have positive effects in vasculardementia. 0 1997Elsevier Science Lld