Mark Blackburn v. Shire US Inc, 18 F.4th 1310

Blackburn took Shire’s prescription mesalamine drug LIALDA for about 12–16 months; LIALDA’s label warned renal impairment may occur and advised evaluation of renal function “prior to initiation” and “periodically while on therapy.”
Blackburn’s gastroenterologist, Dr. Ferrante, did not order baseline or periodic renal blood tests during treatment; Blackburn missed a scheduled two-month follow-up and later relocated and stopped the drug in early 2015.
In April 2015 Blackburn was diagnosed with advanced chronic interstitial nephritis (stage four); experts opined the injury was detectable months earlier and would likely have been prevented by earlier cessation of LIALDA.
Blackburn sued Shire in Alabama state law tort claims; district court dismissed all claims except failure-to-warn and later granted Shire summary judgment on causation grounds, concluding Ferrante did not read the label and would not have changed care.
The Eleventh Circuit concluded genuine factual disputes exist about what Ferrante would have done and certified two determinative Alabama law questions to the Supreme Court of Alabama: (1) whether a drugmaker’s duty to warn can include instructions to mitigate known risks, and (2) whether causation can be shown by proof the physician would have altered monitoring/treatment even if he still would have prescribed the drug.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Denial of further leave to amend	Blackburn sought another opportunity to amend dismissed warranty and fraud counts.	Shire argued further amendment was untimely and futile.	District court did not abuse discretion; denial affirmed.
Summary judgment based on Ferrante not reading label / missed follow-up	Ferrante testified he was familiar with the label, would have heeded a clearer monitoring instruction, and would have monitored differently — creating a factual dispute.	Shire argued Ferrante didn’t read the label, didn’t test, and Blackburn missed follow-up, so no causal link as a matter of law.	Eleventh Circuit: factual disputes preclude affirming summary judgment on those grounds.
Whether duty to warn can include mitigation/monitoring instructions (learned intermediary)	Blackburn: duty includes providing clear instructions for safe use/monitoring to allow physicians to mitigate warned risks.	Shire: duty limited to warning of risk; physicians decide mitigation once warned.	Question certified to Alabama Supreme Court.
Whether proximate causation can be shown by changed monitoring even if drug still would have been prescribed	Blackburn: proximate cause may be shown if physician would have monitored/mitigated differently and thereby prevented injury.	Shire: causation requires that physician would not have prescribed the drug at all.	Question certified to Alabama Supreme Court.

Wyeth v. Levine, 555 U.S. 555 (manufacturer duty to provide adequate warnings/instructions)
Weeks v. Wyeth, 159 So.3d 649 (Ala. 2014) (prescription-warning adequacy measured as to intermediary; causation requirement)
Stone v. Smith, Kline & French Lab’ys, 447 So.2d 1301 (Ala. 1984) (manufacturer duty to warn users of product dangers)
E.R. Squibb & Sons, Inc. v. Cox, 477 So.2d 963 (Ala. 1985) (causation standard in failure-to-warn claims)
Gurley v. Am. Honda Motor Co., 505 So.2d 358 (Ala. 1987) (but-for and proximate causation discussion in product-liability context)
Stahl v. Novartis Pharms. Corp., 283 F.3d 254 (5th Cir. 2002) (recommended medical monitoring can be instructions for safe use)
Toole v. McClintock, 999 F.2d 1430 (11th Cir. 1993) (physician testimony can create jury question on causation)