Does isotretinoin cause back pain?

Ive been taking isotretinoin daily dose 20 mg for 2-3 weeks and ive been getting this painful lower back pain after i stand up after having bent over for half a minute or more and also i get the pain when im lying down straight on my back, but only when i do those 2 things i get the pain so far. Im worried of this being permanent or something if i stay on the drug.