In November 2006 Thailand's Ministry of Public Health issued a compulsory licence for the Merck-patented AIDS drug Efavirenz. This announcement was followed by two other compulsory licences issued in January of 2007, for the AIDS drug Kaletra and the cardiac drug Plavix. Compulsory licensing is an oft-used mechanism under article 31 of the Agreement on Trade-Related Aspects of Intellectual Property Rights (‘TRIPS Agreement’ or ‘TRIPS’) but Thailand's action was notable as it represented the first use of a compulsory licence for a second-line antiretroviral – at once more lucrative and more effective than the first-line AIDS drugs that had preceded it. In the context of the access to essential medicines debate, this was the confrontation that drug companies, civil society and their derivative allies had been anticipating.