A while back my girlfriend got a prescription to Cipro for an ear infection. Afterwords she did some research and founf out that it can have permanent side effects.
Here's an article about it: http://www.ph.ucla.edu/EPI/bioter/ciprodownside.html
For those who don't know, Cipro is one of the strongest antibacterials. Here's a link that provide a good range of information (pros vs cons, etc) http://www.healthsquare.com/newrx/cip1082.htm
Anyway, after the Coming Zombie Apocalypse, this shit is going to be a valuable commodity. I'll be able to trade it for lots of stuff; firearms, food and water, and other supplies.
Arguably, Cipro could counteract the infection if taken in high enough a dose.