Hi, Thanks for your question. I'm Dr. Hasan and I'll try to help you. If you take your blood pressure medicines regularly in morning, you must take it in morning with a small sip of water. You shouldn't skip it at all. As far as antibiotic is concerned, you shouldn't take it on empty stomach as it can result in stomach irritation and other side effects. Keep your antibiotic pill with you and inform your doctor in operating room that you haven't taken the antibiotic. They can give you antibiotic through intravenous route before surgery. So to conclude you should take your blood pressure pill with sip of water and should avoid taking the antibiotic. I wish you all the best for your surgery. My goal is to provide you with excellent service – if you feel you have received anything less, please reply back as I am happy to address follow-up questions. Kindly rate me when you are done. You can come back here to ask anything even after you have rated the answer. I will be glad to help you always.