Following an expiration date is important no matter what is in question. The facts are that the item in question has been found that under normal conditions it only remains effective for a set amount of time (a time that can easily be effected by abnormal conditions such as prolonged exposure to heat which can make the item expire sooner). After this time, the item becomes ineffective, meaning it is pointless to even take it, and at times it can even become harmful. Medication is simply no exception.
It has been a common practice for most to ignore the expiration date on their medication. The danger of using expired medication is simply undeniable. Similar to expired foods, expired medication not only loses its effectiveness, it also can become dangerous to use these medications because the chemicals have been altered due to various exposures and these changes can be detrimental to your health. Also very similar to foods, although it may not be deadly, your body won't accept the medication, it won't do what it was intended to do, and it can even make you sick in a variety of ways.
The dangers are only compounded when many over the counter drugstores are selling already or soon to be expiring medication. On average, over the counter medications should be disposed of after six months and prescription medication should be disposed of after a year before they expire. However, when the medication being purchased and the person purchasing the medication isn't careful enough to check the expiration date on the container, the danger is only worsened.
Although it may seem like a simple idea of what not to do, taking expired medication is actually a common practice. It is surprising as to how many people simply never even think to look at the expiration dates on their medication before taking them. If you are taking medication, it is highly recommended that you go through and clean out your medicine cabinet sometime soon and check all of the expiration dates just to be safe.
Hope this helps.