▴ Propentofylline (HWA 285) is a novel xanthine derivative which is being developed for the treatment of primary degenerative (Alzheimer's) and vascular dementia.▴ Propentofylline enhances extracellular adenosine levels via inhibition of adenosine uptake, and prevents the enzymic degradation of cyclic adenosine monophosphate and cyclic guanosine monophosphate through inhibition of cyclic nucleotide phosphodiesterases.▴ It modulates the activation of microglial cells, reduces or prevents various aspects of neuronal damage, and has beneficial effects on cognitive behaviour and performance in animal models of ischaemia.▴ In placebo-controlled studies lasting up to 12 months in patients with mild or moderate Alzheimer's or vascular dementia, propentofylline prevented clinical deterioration and produced significant clinical improvement according to most, but not all, efficacy evaluations.▴ Propentofylline appears to be generally well tolerated; gastrointestinal disturbances, dizziness, headache and heartburn were the most common adverse events during clinical trials.