I presume you're referring to lithium carbonate. Shaking hands is a symptom of acute elemental lithium toxicity, why wasn't the doctor monitoring your levels? This often happens when lithium is started too high or ramped up too fast. It goes away on its own after your body adjusts. In your case it sounds like the doctor should have started you at a lower dose, it should never be so pronounced that it forces you to stop treatment.

Using free elemental lithium (i.g. lithium carbonate, lithium citrate) to control the acute phases of this illness is akin to the delicate balance of chemo therapy. In chemo, the dose has to be high enough to kill the cancer, but too high and it will also harm the patient. Elemental lithium does have a very narrow therapeutic range, and it's right up against its toxic threshold. However, you don't need that high a dose for maintenance, and for prophylactic use trace amounts have been show to be effective.