Is it possible to split the dose of an antidepressant?

Hello, I was wondering if it is possible to split the intake of an antidepressant if you have digestive problems? I am currently taking fluoxetine 10 mg but it is quite possible that I will have to increase to 20 mg if 10 mg is not effective. However, I have taken antidepressants before and in the last few years, every time I increased the dose, I had heartaches or dizziness that was a bit stressful. Same thing if I eat heavy, rich or sweet food. It seems that my liver is tired... So I wanted to know if 2 doses of 10 mg at 12 hours interval is equivalent in terms of efficiency... it seems to me that it would lighten my digestion...? I thank you! :) Melanie