Complex sentence: It was part of the storyline inloving Joe's addiction to painkillers, after a back injury he was given painkillers to easy the pain he told Dr Patel that he back was healing, so he wasn't given any more prescriptions.
Split into simpler sentences: It was part of the storyline inloving Joe's addiction to painkillers, after a back injury for which he was prescribed the drugs to ease the pain. After telling Dr Patel that his back was healing he wasn't given any more prescriptions.