Atripla, which combines efavirenz, emtricitabine and tenofovir disoproxil fumarate, can now be used throughout the 27 countries of the EU.
Previously only available in the US, the drug is manufactured by three rival companies, Gilead Sciences, Bristol-Myers Squibb and Merck Sharp & Dohme Limited.
Dr Brian Gazzard, clinical research director at Chelsea and Westminster Hospital in London said: 'Historically, HIV treatment regimens have been a challenge for many patients since they often combine multiple medications with complex dosing schedules.
'Atripla combines three clinically proven and well-established anti-HIV medicines in a single once-daily pill and represents an important step forward in dosing simplification,' he said.
Atripla is currently the most-prescribed treatment for HIV-diagnosed patients in America since its approval by the US Food and Drug Administration in July 2006. It will now be available through the NHS at the discretion of PCTs and GPs.