Cocaine also affects the reward pathways in the brain, use over a long period of time diminishes the sensory reward of other experiences.
For example, sex. If you repeatedly use cocaine as a supplement to sex, you will start to enjoy sex less.
Repeated cocaine use can also affect stress hormones, elevating them, often meaning that people seek out more cocaine to alleviate their stress.
It's also worth noting that a lot of the time cocaine isn't only cocaine.
The emergence of a two-tier market has occured, with average purity levels rising in the UK and elsewhere in Europe over the last five years, but despite this, most of the gram you buy isn't cocaine, and it really isn't harmless.