Bryan Ranes v. Adams Laboratories, Inc.; Adams Respiratory Therapeutics; Owl Pharmacy; Frank Reznicek; Amanda Mathews; Hy-Vee, Inc.; McKesson Corporation; and Michael Rinaldi

Summary

The Iowa Supreme Court affirmed summary judgment for defendants in a toxic-tort action alleging that ingestion of phenylpropanolamine in Aquatab C caused neurological injuries. The court held that the plaintiff’s toxicology expert was qualified to testify regarding general causation but that his methodology and opinions were insufficiently reliable to establish specific causation. The court upheld exclusion of the expert testimony and dismissal of the claims.

Holdings

1. In a toxic-tort case involving complex medical and scientific causation issues, the trial court may apply relevant Daubert considerations as part of its gatekeeping function under Iowa Rule of Evidence 5.702.
2. A toxic-tort plaintiff must establish both general causation—that the substance is capable of causing the relevant type of harm—and specific causation—that the substance actually caused the plaintiff's alleged harm.
3. An expert need not be a specialist in the precise field at issue, but must possess knowledge, skill, experience, training, or education adequate to answer the particular question presented. Dr. Thoman was qualified to address the general effects of PPA but was not qualified to diagnose Ranes with complex neurological vasculitis.
4. Case reports and a case-control study that do not address the injury alleged by the plaintiff, standing alone and without a reliable supporting methodology, cannot establish general causation.
5. A differential diagnosis is unreliable when the expert fails to reliably rule in the alleged toxin, fails to consider alternative causes, or diagnoses the alleged disease solely from symptoms while disregarding contrary diagnostic evidence.
6. When expert causation testimony is properly excluded and the plaintiff lacks other evidence sufficient to create a jury question on causation, summary judgment is proper on claims requiring proof that the defendant's product caused the alleged injury.

Questions Presented

1. Whether the district court abused its discretion by excluding Dr. Thoman's expert testimony concerning general and specific causation.
2. Whether Dr. Thoman was qualified to diagnose Ranes with vasculitis and opine that PPA caused Ranes's alleged neurological injuries.
3. Whether the exclusion of the causation testimony left insufficient evidence to create a jury question on causation and therefore justified summary judgment for the defendants.

Disposition

affirmed