You can Google Antabuse...it's not for helping withdrawal, it's more a deterrent from further drinking once you're through the detox and initial stages.
The UK does things quite differently than the US where I live. In-patient treatment might be your only option if you are looking for drugs to ease withdrawal, I'm not sure. Maybe start a thread asking for UK input. Are you in the alcohol services system? (I'm not sure what it's called...)
In the US the options are much more varied and some doctors here would prescribe a short course of at-home medication if they felt the patient might be able to do it at home, or there are in-patient detoxes and/or the hospital.