Can medication lose its effectiveness when taken with cola? If so, why?

No real answers, but:
Taking tylenol with a caffeinated beverage can help with migraines.
http://answers.yahoo.com/question/index;_ylt=Ai_WgCkEtONBYGwWJ.2YDursy6IX?qid=20060717194526AALjYj8

According to a study, taking sleeping pills with soda can cause heartburn.
http://www.azomed.com/?id=9953

I was able to find a couple of bulletin boards and blogs where the writer warned against taking meds with soda, but there was no explanation as to why. I was also able to find on BB that said that in the 70's people would take meds with soda to "get high."

There are ingredients and acids that are in cola. The colas can have a chemical reaction with the medication, and it will lose its effectiveness or even cause side effects. It is always recommended to take medication with water, sometimes milk.

Yes, because Colas increase the acidity of the stomach. But it depends on the medicine, not all medicines are affected by the increased acidity. Cola's have high sugar content, which can make some medicines seem more effective when taken with Cola.

I would stick with the advice in other answers, take medicine with water, unless a doctor advises you otherwise.

re: Cola/acidity
Yohoho05 - Here's a reference re: Cola, acidity and enhanced absorbtion of a specific medicine -- http://gateway.nlm.nih.gov/robot_pages/MeetingAbstracts/102244631.html

My reference shows that Cola's increase stomach acidity. Yes, I believe this applies to everyone, not just the population being discussed in the study.

Yohoho05 -- if you are so sure this answer is wrong, please write a better one -- I couldn't find any reference that told me there are absolutely no contraindications for combining Cola's with medicine. That's what the question asks.