I don't see a Pdoc just my GP, but when my GP prescribes something new he always has me come back in 4 weeks. One time he was introducing more than one new med - my T had told me to go in and ask for x and x. He only prescribed one had me come back in 4 weeks, then we talked about the second one and he prescribed that and had me come back in 4 weeks. I did well on both so I didn't have to come back for a while. But I know when he precribed for my EX-husband, he wasn't getting optimal results so my husband had to keep coming back and finally (after 2 or 3 times) my GP sent him to a Pdoc. If your pdoc wants you to come back sooner please do - lithium needs to monitored as how your body reacts - it can cause medical conditions if not your body doesn't respond well. I know it is a pain but better safe than sorry.