The invention provides a method of inhibiting the effects of platelet activating factor (PAF). For instance, a disease or condition mediated by PAF (particularly inflammation) can be treated or platelet aggregation can be inhibited. The invention also provides a method of inhibiting the production and/or release of interleukin 8 (IL-8) by cells. The effects of PAF and the production and/or release of IL-8 are inhibited according to the invention by a compound of the formula: wherein R1 and R2 are defined in the application, or a physiologically-acceptable salt thereof. The invention also provides pharmaceutical compositions comprising these compounds.