I took an online college algebra, and for myself found it better than the instructor I dropped (couldn't understand his accent!)
Anyway....I have taken other classes over. I really think it all depends on your school. With the program I plan to apply to, the lady that talked in the information session actually told us if we don't get in the first time, try looking to see if there are any classes we can retake to get the grade up. (It goes by prereq GPA, then by non-nursing course credits, then by non-nursing course GPA.)
Good luck. I think most schools will not look too badly at it. If you are determined to finish school, and are smart enough to know you can't handle something at that time, then it is better to drop and retake than to fail a course, and quit school.
Good luck!