Students are being warned about the dangers of prescription medication used to boost their brain function at exam time.

New figures show the number of imported drugs seized by customs, which are normally prescribed for conditions like ADHD, doubled between 2011 and 2014.

Doctor Chris Luke is a Consultant in Emergency Medicine at Cork University Hospital.

He says a new drug called ‘brain Viagra’, which is being sold online, can have unpleasant side effects.

“The most common problems we are likely to see are; upset stomach, abdominal pain, nervousness, jitteriness and nausea. So they’re not great side effects leading up to exams,” said Luke.