I always tell my patients that they can drink water prior to a lipid panel and water isn't going to affect the glucose either. I also tell my patients to take all their routine medications the morning of their tests, with the exception of medications that are taken with food.
When I worked on the floor, we gave all routine meds to patients who were NPO just for lab work and we didn't restrict water for them either. Heck, we gave many routine PO meds with sips of water even for those patients who were NPO for surgery. You don't want out of control BPs in surgery. Of course, that was left up to the doc to order, but if he didn't order routine meds or order them held, we double checked. Most often unless they wrote "Hold all medication day of surgery" they meant for us to give them.