Exactly How Accurate Are The Expiration Dates On Pills

Today is August 1st, 2013. This Claritin expired "July 2013"

The foil back of a Claritin pill packet laying on a wooden table. The foil is dimpled with a cross-hatch of tiny squares. A few lines of bolier plate text are followed by an exporation date of 7/13

Probably won't kill me, right?