When it comes to poor academic performance, the most important thing to discuss is not explaining reasons for why they occurred but what you have done to rectify the situation. With every cause of bad grades, one can come away with a negative impression. Even if you failed classes because you fell ill, one can easily conclude that a mature decision could have been preemptive withdrawal from the semester. So in trying to explain why bad grades occurred, one can find deficiencies in your decision-making... so trying to explain away bad grades is a non-starter. But to show your maturity, be able to unquestionably and tangibly point to changes you have made in your decision-making and academic performance which puts the school at ease and helps them see that you are a) a good student and b) not likely to make the same academic mistakes again.
As far as compounding is concerned, it doesn't give you any leg up on anyone else, but it may give you a different perspective which, if enlightening, you could discuss. Schools want to know that you are not entering pharmacy school clueless about the profession. Having more experience is always a good thing and explaining how your additional experience has developed your view of the profession can be useful to you on application.
