Who is responsible for not noticing a new prescription should not be taken with a current one?

We caution all potential clients that medical malpractice claims are very difficult to win - few settle and those that are tried are won by the doctor 9 out of 10 times.  Those cases which have the best chance for a good outcome for the plaintiff are those where a clear act of negligence, or omission of appropriate care, are apparent in the medical record. From your facts, there may be a claim for negligent care against the prescribing physician as well as the pharmacy. But much will depend upon the specifics of your mother's medical history. However, even if negligence can be established, I am uncertain  that it would still be in your best interest to pursue a case.  We estimate that the litigation expenses alone, excluding attorney fees, will run $30,000 to $50,000 for the "average" medical malpractice case - these are costs for which the plaintiff is responsible regardless of the outcome of the claim.  Only those cases where there is catastrophic injury requiring significant future medical expenses do the damages warrant the risk of litigating the claim.  If your mother has in fact suffered significant renal injury because of the drug interaction, she may wish to consider a lawsuit.  But if she is expected to fully recover, it probably would not be advantageous.  Please keep in mind that you have a two year statute of limitations in Colorado for filing a medical malpractice claim, you must file within two years of the act of negligence or lose your right to do so.  Other time limitations may apply.