The most common treatment in the US, Canada and the UK is Truvada. This is what is known as a "fixed-dose combination tablet" combining emtricitabine and tenofovir from the NRTI class, and raltegravir, from the integrase inhibitor class. There ARE alternative drugs available and possibly in Thailand they use lamivudine in place of raltegravir. I am definitely NOT a chemist, so I can't tell you for sure if the combination you're taking is appropriate. You should discuss your concerns with the doctor who prescribed PEP or a pharmacist/chemist. I wish you the best.
Anal, oral or vaginal and was it protected?