Warfarin range, side effects research???

[catwoman]

This is probably a question for Al Lodwick.

How have INR ranges been established for warfarin?

How is a list of side effects determined for drugs (Rx or OTC)? What percentage of participates in a trial study must experience a side effect before it's labeled an "adverse reaction"??

 

[Guest]

The INR ranges were detrermined by a consensus of a committee. This is another reason that I don't worry too much about slight variations outside the range. As you all know one strong-willed committee member can sway the decision.

If you are doing a FDA-approved study for approval of a new drug and even one person says that they had a dry mouth then dry mouth gets reported as a side effect. There are also post-marketing surveys. These reports also have a way of finding their way into the warnings. Example: Cranberry juice. A few people ask if there was an adverse effect. Next thing you know somebody can remember one person who died after drinking cranberry juice with warfarin. Then suddenly the FDA makes it sound like you will drop dead the instant cranberry juioce touches the lips of a warfarin-taker.