Take them when you want. It shouldn't make much difference. You could try spreading them to twice a day 12 hours apart.

Depending on the kind of Accutane, it could be best to take it with a high fat meal (for much better absorption). I take mine at the morning with milk.

My derm told me to take all my pills at once. I took them after my evening meal because I figured that this meal will be the highest meal in fat for me so absorbtion will be at its best

Thanks