LAMIVUDINE (3TC )(Combivir - with AZT) What is 3TC 3TC is an antiretroviral (anti-HIV) agent, which belongs to a class of drugs called nucleoside analogue reverse transcriptase inhibitors . 3TC is used in combination with other antiretrovirals to suppress the HIV. How should you take 3TC the usual dose is 150mg (1 tablet) twice daily spread out during the waking hours the dose may be less ...