The Food and Drug Administration (FDA) voted 9-2 on Friday to authorize the use of the Xarelto (rivaroxaban) anticlotting agent in the fight against stroke in patients with an irregular heart rhythm known as Atrial Fibrillation.

Earlier this week, the potentially lifesaving drug came under scrutiny because of its potential side effects.

Nevertheless, the drug gained advisory approval by seven votes, with one panelist stating there was “a tremendous unmet medical need for new therapies” such as Xarelto.

The disease (AF), affects more than 2.2 million Americans in what is now a $10 billion stroke-fighting market.

However, with today's vote also came opinions over whether the drug was sufficiently capable at replacing the current front-line intervention - Warfarin.

Specifically, panelists held doubts over whether it can replace a drug which so many depend on for life-saving benefit.

"I've heard nothing that convinces me that rivaroxaban should be first-line treatment for many patients," said Allan Coukell, panelist representing patients and director for medical safety at Pew Health Group.

In tests so far, Zarelto has not been proven to be better, especially as Warfarin dosing varies according to its patient's requirements, making it very tricky to fine tune.

"I still think the agency should not approve this drug without having the data on what to do when you stop the drug," said Dr. Nissen, chair of the department of cardiovascular medicine at the Cleveland Clinic Foundation, who voted against the drug being passed through.

Final recommendation is scheduled for Nov. 4, J&J - the drug's manufacturer said.