vicky,
Thanks for your question.
Blood pressure is a very dynamic part of our physiology. It is affected by everything we do including exercise, stress, lack of sleep, and infections. It is quite possible that your higher than usual pressure was induced by your kidney infection. Once the infection is cleared and if your readings remain low, I would ask your physician about the possibility of weaning you off the medication while being monitored closely. If your pressure remains normal during and after the weaning process, then you can stay off your medication.
Best wishes and feel better.
Martin Cane, M.D.