Abstract: A method for inceasing the weight gain and/or improving the feed utilization efficiency and/or increasing the lean body mass and/or decreasing birth mortality rate and increasing post-natal survival rate of livestock comprises the administration to livestock of an effective, non-toxic amount of a compound of formula (I), or a veterinarily acceptable acid addition salt thereof: ##STR1## wherein R.sup.1 is phenyl (C.sub.1-6)alkyl or optionally substituted C.sub.1-6 alkyl, andW is optionally substituted phenyl, a heterocyclyl group, or phenoxymethyl optionally substituted on the phenyl group. Certain compounds of formula (I) are novel.

Abstract: A method for the treatment of cerebral vascular and neuronal degenerative disorders associated with learning, memory and cognitive dysfunctions including cerebral senility, multi-infarct dementia and senile dementia of the Alzheimer type and/or peripheral vascular disease and/or proliferative skin disease in mammals, such as humans, which comprises administering to the mammal in need of such treatment an effective amount of 1,3-di-n-butyl-7-(2-oxypropyl) xanthine or a pharmaceutically acceptable salt thereof.