How do painkillers know where it hurts?

Can haemorrhoid cream treat under-eye bags, how much radiation was released from Fukushima, why is the moon larger on the horizon, what constitutes stamina, are mobile masts making me ill, why does logic vary between individuals and how does a drug know where to go in the body? Join Dr Chris for the answers and news of the E. coli outbreak in Europe and a new molecule to render mosquitoes anosmic! Like this podcast? Please help us by supporting the Naked Scientists