What are some of the effects of lamivudine?

Hardly any: Do you mean effects or side effects? Lamivudine (3tc, epivir) is a drug that's used in combination with others to stop HIV replication and treat HIV infection. It is one of those rare drugs that has virtually no side effects in most people who take it. There are occasional exceptions, as with any drug, but it is extremely well tolerated by most people.