Patients w/ known risk factors for QT prolongation interval eg, congenital long QT syndrome, known history of acquired QTc prolongation, medicinal products known to prolong QTc interval & hypokalaemia; hypomagnesaemia; known or suspected heart disease; pulmonary HTN. Not recommended in patients w/ elevated transaminases (>5 times upper limit of normal). Monitor complete blood count (eg, Hb, WBC & platelet count); assess liver & renal function & electrolytes. Regularly monitor ECG or echocardiography prior to & during treatment. Not recommended in concomitant use w/ other PDE III inhibitors eg, milrinone, amrinone, enoximone, olprinone, cilostazol. Concomitant use w/ acetylsalicylic acid. Galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption. May affect ability to drive & use machines. Renal or hepatic impairment. Not recommended in moderate or severe hepatic impairment. Women of childbearing potential should use effective contraception during treatment. Not recommended during pregnancy. Not to be used during lactation. Childn & adolescents. Elderly >60 yr.