Health Minister Mongkol Na Songkhla said not enough people are able to afford Kaletra and Plavix under their current prices. About half a million people in Thailand have HIV, but the country is only able to provide anti-AIDS medications for a fifth of them.
"We have to do this because we don't have enough money to buy safe and necessary drugs for the people under the government's universal health scheme," Mongkol told reporters, according to BBC News.
Mongkol said the decision was permissible under international trade rules in the event of national public health emergencies.
Plavix, a blood-thinning medication to prevent heart attacks, is thought to be the second-largest medication sold worldwide. Mongkol said that the cost of a generic version of the drug would be about a tenth of Plavix's cost.
Pharmaceutical firms said the approval caught them off guard.
"They are concerned about continuing to invest in a country where the government cannot provide a basic guarantee for the safety of their assets," the Pharmaceutical Research and Manufacturers' Association said.
But AIDS activists have praised the move.
"It is a brave decision, despite both anticipated pressure from industry and possible threats to withdraw investments," said Kannikar Kijtiwatchakul, of aid agency Medecins Sans Frontieres.
"The authorities have engaged in dialogue with companies before, but the discounts have been marginal. The licenses will benefit a lot of people and will set an example to other countries who face the same problem."
