Ana Hick, 18, collapsed outside the Twisted Pepper in Middle Abbey St at around 3am on Saturday. She was rushed to the Mater Hospital after reportedly suffering a heart attack and seizures.
She remained in a serious condition in hospital before passing away yesterday at approximately 5.30pm.
The tablets reportedly contained PMMA, an amphetamine-based chemical which is often passed off as ecstasy, which normally has the active ingredient MDMA.
PMMA has been implicated in a number of deaths here in recent years.
Gardaí confirmed officers at Store Street had initiated an investigation.
An autopsy and toxicology tests are expected to be carried out to determine the exact cause of death.
A source said if there was any “criminality” involved, that would be investigated.
The venue outside which Ms Hick collapsed posted the following message on its Facebook page: “Everyone at the Twisted Pepper is deeply saddened and devastated at the news of the sad passing of Ana Hick.
“Our thoughts and prayers are with Ana’s family and friends at this tragic time. We are working closely with the authorities.”
Ms Hick, a Dún Laoghaire native and former Loreto College student, had been studying at the Irish Film Academy and working at Crunch Fitness.