A 22-year-old primigravid woman at term comes to the labor room because of painful contractions every 2 minutes. She has had no gush of fluid and no bleeding from the vaginA. Her prenatal course was unremarkable. She takes no medications and has no allergies to medications. Examination shows that her cervix is 6 cm dilated and 100% effaced; the fetus is at 0 station. The fetal hea rate has a baseline in the 150s and is reactive. The patient desires an epidural for pain relief. Which of the following should be given orally sholy before the epidural is placed?