An animal deworming tablet is being touted as the new drug of choice by clubbers. A leading medical expert has told Sky News it can cause heart and brain problems or lead to fits. Benzyl piperazine was taken by an 18-year-old woman who collapsed in a London nightclub and suffered a seizure. It is considered a legal alternative to other recreational drugs such as Ecstasy - although its unlicensed sale has now been outlawed. Doctors warned over reactions