A term multigravida, who is receiving oxytocin for labor augmentation, is requesting pain medication. Review of the client's record indicates that she was medicated 30 minutes ago with butorphanol tartrate 2 mg IV push and promethazine 25 mg IV push. Vaginal examination reveals that the client's cervical dilation is 3 cm, 70% effaced, and at a 0 station. Which action should the nurse implement?