The question of whether autism-related drug lawsuits will face state-level legal challenges nationwide is increasingly relevant, especially in light of recent developments surrounding acetaminophen (commonly known by the brand name Tylenol) and its alleged links to autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). While federal multidistrict litigation (MDL) efforts have encountered significant hurdles, state courts across the United States are becoming a critical battleground for these claims.
At the heart of these lawsuits is the allegation that manufacturers and retailers of acetaminophen failed to adequately warn pregnant women about potential risks of prenatal exposure to the drug, which plaintiffs claim may increase the likelihood of their children developing autism or ADHD. The legal theory primarily revolves around “failure to warn,” a product liability claim asserting that companies should have disclosed known or reasonably knowable risks associated with their products.
Federal courts have seen mixed outcomes. For example, a major federal MDL involving Tylenol autism claims was dismissed in 2023 after a judge ruled that the plaintiffs’ scientific experts did not provide sufficiently reliable evidence to establish a causal link between acetaminophen use during pregnancy and autism or ADHD. This ruling was a significant setback for plaintiffs in federal court. However, the dismissal is currently under appeal, and the appellate court’s decision could reopen the federal litigation if it overturns the lower court’s ruling.
Meanwhile, plaintiffs’ attorneys have shifted focus to state courts, where litigation is actively proceeding in several states including California, Pennsylvania, New Jersey, Illinois, and Delaware. State courts may apply different evidentiary standards, particularly regarding expert testimony, which can make it easier for these cases to survive early legal challenges. This means that even if federal cases remain stalled or dismissed, families seeking legal recourse may still pursue claims at the state level.
Some state courts have already allowed cases to move forward, reflecting a more favorable environment for plaintiffs. For instance, courts have rejected motions to dismiss claims against retailers and manufacturers, recognizing that federal regulations do not necessarily preempt state law claims about inadequate warnings. This legal nuance opens the door for lawsuits alleging that companies should have included warnings about the potential developmental risks of acetaminophen use during pregnancy.
The broader context includes ongoing scientific and governmental scrutiny. While no definitive medical consensus confirms that acetaminophen causes autism, emerging studies and government investigations have prompted increased attention. The U.S. Department of Health and Human Services has launched efforts to identify environmental and pharmaceutical factors contributing to autis
