Can i take aciclovir. Take the medicine?

My doctor prescribed my 400mg aciclovir every 8 hours(3x a day basically for 10 days) as i had hsv(1+2 igm) as 1.38 and positive. While igg is negative for the same. So he said it's highly unlikely you have herpes, as the girl with whom i had sex and seeing her for last 2-3 months, she tested negative. And if it was past infection I would've gotten my igg in higher numbers as well. So, my question is this medication safe for kidneys? I have malrotated ectopic left kidney.. in dec i did a KFT which showed a slightly elevated creatinine? But when i repeated the test after a week it was normal only.(could that be possible as i had eaten a lot of nonveg the before day and night?). And in the second kft my potassium was slight higher and after that i never checked it again. So in these circumstances, can I take the medicine? Please guide me