Iowa: Medical expert can’t testify about cold medicine

A medical expert cannot testify in a products liability case that prescription cold medicine containing phenylpropanolamine (PPA) causes brain injury, the Iowa Supreme Court has ruled.

The plaintiff ingested “Aquatab C” and immediately felt pain in his head and numbness on his left side. In ensuing years he saw a battery of doctors for pain in virtually every part of his body, but no neurological abnormalities were found in CT or MRI scans, and stroke was ruled out.

He sued the cold medicine manufacturer for products liability and hired an expert who would be the only person at trial to testify that PPA causes brain injury.

But the Iowa Supreme Court said that his testimony was not reliable to show causation.

“[The doctor] used one case-control study… in his general causation analysis. The study concluded that PPA was likely to cause hemorrhagic stroke in women, but … in men showed no increased risk. … [He] reasoned from this study [that] PPA can likely cause stroke and since [the plaintiff] likely suffered a ‘stroke-like event,’ this study tended to show a relevant causal connection. This study is simply not relevant to the case before us. It excludes men and … does not describe an injury following PPA ingestion called ‘stroke-like event’ … [and] as such … cannot be the basis of any general causation opinion,” the court said.

Further, “[s]pecific causation in toxic-tort cases examines whether the toxin at issue could have reasonably caused plaintiff’s specific alleged injuries. … Since [the plaintiff] has failed to reliably show [that] PPA is an external factor to be ‘ruled in’ to a differential causation diagnosis, it follows he cannot establish PPA caused his specific injuries.”

Iowa Supreme Court. Ranes v. Adams Labs, No. 06-1428. Feb. 5, 2010.