A pharmaceutical composition containing as an essential ingredient a compound of the formula ##STR1## wherein one of the groups R.sub.1, R.sub.2 and R.sub.3 is an .omega.- or (.omega.-1)-hydroxyalkyl group having from 5 to 8 carbon atoms in which the hydroxy group is separated from the xanthine nucleus by at least 2 carbon atoms, radicals R.sub.1 and R.sub.3 which are no hydroxyalkyl group, are hydrogen or methyl and equal or different, and R.sub.2 is said hydroxyalkyl group or methyl, a compound of formula (I) and a pharmaceutical product for treatment of diseases involving insufficiency of cerebral blood flow.