The present invention relates to administration of a dinucleoside polyphosphate analogue or a pharmaceutically acceptable salt thereof, topically in a formulation comprising a suitable excipient or using a device for transdermal delivery, and/or combined with a nanoparticle carrier. The present invention also relates to the therapeutic use of such compositions or devices, in particular in the treatment of painor epilepsy. The analogue may be combined with an anaesthetic (such as a salt form) or delivered in a nanoparticle.