In re Zicam Cold Remedy Mktg. Sales Practices, & Prods. Liab. Litig., 09–md–2096–PHX–FJM.

• Decision Date: 03 June 2011
• Docket Number: No. 09–md–2096–PHX–FJM.,09–md–2096–PHX–FJM.
• Citation: 797 F.Supp.2d 940
• Parties: In re: ZICAM COLD REMEDY MARKETING, SALES PRACTICES, AND PRODUCTS LIABILITY LITIGATION.This Document Relates To: All Personal Injury Actions.
• Court: U.S. District Court — District of Arizona

797 F.Supp.2d 940

In re: ZICAM COLD REMEDY MARKETING, SALES PRACTICES, AND PRODUCTS LIABILITY LITIGATION.This Document Relates To: All Personal Injury Actions.

No. 09–md–2096–PHX–FJM.

United States District Court, D. Arizona.

June 3, 2011.

ORDER

FREDERICK J. MARTONE, District Judge.

We have before us defendants' motion for summary judgment on the issue of general causation (doc. 1374), plaintiffs' response (doc. 1412), and defendants' reply (doc. 1426).¹

I. MDL Background

Plaintiffs allege that their use of Zicam Cold Remedy Intranasal Gel Spray or Swabs caused them to lose their sense of smell. For a description of the Zicam intranasal products, see our Order on Defendants' Motion to Exclude Plaintiffs' Causation Experts (“ Daubert Order ”) at 2–3 (doc. 1360).

Defendants moved to exclude the opinions of four of plaintiffs' experts, see Motion to Exclude Plaintiffs' General Causation Experts (doc. 1061); Motion to Exclude Plaintiffs' Expert Jay Sirois (doc. 1063), which we granted in part and denied in part. We admitted Dr. Greg Davis's opinions about (1) the diffuse location of olfactory tissue in the nose, and (2) the toxicity of Zicam. Daubert Order at 19. We admitted Dr. Ashim Mitra's opinions about (1) the distribution and deposition of Zicam within the nasal cavity, (2) the principle of diffusion, and (3) the effect of the preservative benzalkonium chloride on the absorption of Zicam. Id. at 23. We admitted Dr. Steven Pike's opinions about the toxicity of Zicam to olfactory epithelium (“OE”) and its potential to cause anosmia, but excluded his reliance on certain studies. Id. at 28.²

II. Legal standards

We grant summary judgment if defendants show “there is no genuine dispute as to any material fact and the movant is entitled to judgment as a matter of law.” Fed.R.Civ.P. 56(a). We draw all justifiable inferences in favor of the non-moving party. Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255, 106 S.Ct. 2505, 2513, 91 L.Ed.2d 202 (1986).

Plaintiffs assert causes of action under the products liability laws of their respective states. In a products liability action brought in federal court pursuant to diversity jurisdiction, we apply state substantive law. Stilwell v. Smith & Nephew, Inc., 482 F.3d 1187, 1193 (9th Cir.2007). As an MDL transferee court, we apply the substantive law of each transferor forum. Ferens v. John Deere Co., 494 U.S. 516, 525, 110 S.Ct. 1274, 1280, 108 L.Ed.2d 443 (1990) (choice-of-law rules do not change following a transfer). It is uncontested that each transferor forum applies the substantive law of the place where plaintiff resides, purchased the product, and was injured. See Motion at 15.

The parties also agree that each applicable state requires plaintiffs to prove general and specific causation for their claims for negligence, strict liability, failure to warn, breach of warranties, and consumer fraud. See Motion at 16. Plaintiffs must show a causal link between their alleged injury, anosmia, and their use of Zicam, the allegedly defective product. “General causation” means “whether the substance at issue had the capacity to cause the harm alleged.” In re Hanford Nuclear Reservation Litigation, 292 F.3d 1124, 1133 (9th Cir.2002). The general causation inquiry is “whether exposure to a substance for which a defendant is responsible ... is capable of causing a particular injury or condition in the general population.” Id. at 1133. Specific or individual causation “refers to whether a particular individual suffers from a particular ailment as a result of exposure to a substance.” Id. Where the distinction between general and individual causation is made, “it must be strictly observed.” Id. at 1135

Defendants move for summary judgment solely on the issue of general causation. They contend that we (and the transferor courts) need not reach the issue of specific causation unless plaintiffs' evidence is sufficient to show that anosmia can be caused by the circumstances of their exposure. Motion at 17 (citing Ruggiero v. Warner–Lambert Co., 424 F.3d 249, 254 (2d Cir.2005)).

The admission of significant portions of plaintiffs' experts' opinions does not necessarily mean that the evidence is sufficient to support the general causation element of plaintiffs' claims. See Stilwell, 482 F.3d at 1195 (affirming grant of summary judgment because the inclusion of the rejected testimony of plaintiff's expert does not establish causation). Even where scientific evidence “meets the standards of Rule 702,” summary judgment may be an “appropriate safeguard.” Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 596, 113 S.Ct. 2786, 2798, 125 L.Ed.2d 469 (1993). “[P]roof of causation must be such as to suggest ‘probability’ rather than mere ‘possibility,’ precisely to guard against raw speculation by the fact-finder.” Sakaria v. Trans World Airlines, 8 F.3d 164, 172–73 (4th Cir.1993); see also Domingo ex rel. Domingo v. T.K., 289 F.3d 600, 607 (9th Cir.2002) (“bits and pieces of testimony of defendants' experts could not give rise to a triable issue of causation.”). However, as we noted in our Daubert Order, “[v]igorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible evidence.” Daubert, 509 U.S. at 596, 113 S.Ct. at 2798.

III. The delivery of a toxic dose.

To defeat summary judgment, plaintiffs' collective expert opinions and evidence must be sufficient for a fact-finder to reliably conclude that ordinary use of Zicam can deliver zinc ions to the OE in an amount capable of damaging enough OE to cause smell loss in humans. Defendants contend that plaintiffs cannot meet their burden because: (1) evidence of the toxic level of Zicam is insufficient; (2) evidence of how much Zicam reaches the OE is insufficient; and (3) evidence of the location of smell tissue is speculative.

A. Toxic level of Zicam1. Is a showing of a toxic dose required?

Defendants contend that plaintiffs cannot meet their causation burden because they have not demonstrated how much Zicam (or zinc) exposure is necessary to cause smell loss. Motion at 13. Plaintiffs argue they need not prove a “toxic dose,” but rather must simply demonstrate a “causal relationship between the defect and the injury.” Response at 15. We therefore first determine whether plaintiffs must introduce evidence of the level of exposure that could cause anosmia, i.e. whether they must demonstrate a toxic dose.

A central tenet of toxicology is “ ‘the dose makes the poison’; this implies that all chemical agents are intrinsically hazardous—whether they cause harm is only a question of dose.” Fed. Judicial Ctr., Reference Manual on Scientific Evidence at 403 (2d. ed. 2000). An “important component of toxicological research is dose-response relationships.” Id. at 406. This is the concept “that the more intense the exposure, the greater the risk of disease.” Id. at 377. Some causal agents do not exhibit a dose-response relationship. For example, exposure may not cause disease until it exceeds a certain dose. “Thus, a dose-response relationship is strong, but not essential, evidence that the relationship between an agent and disease is causal.” Id.

However, while a Zicam dose-response relationship may exist, determining the toxic dose of a drug is challenging. Drugs, in contrast to toxins, are intended to be ingested. We do not require studies on “living humans with intact physiology and operative metabolic and immune function” to demonstrate “the amount needed to destroy a sufficient amount of OE to compromise smell function.” See Motion at 20. While this sort of study might be helpful to a trier of fact, it presents significant ethical problems. See Daubert Order at 14 (citing Reference Manual at 405).

Given the challenge of determining a toxic dose, and plaintiffs' concession that they have not done so, the issue is whether this failure entitles defendants to summary judgment on general causation. Related to this question is the parties' disagreement about whether plaintiffs' actions arise under the law of “products liability” or “toxic tort.” See Response at 13; Reply at 9. Clearly, there is some overlap between toxic tort and products liability litigation in actions where plaintiffs allege that a product's defect is its chemical toxicity to humans. See, e.g. McClain v. Metabolife Intern., Inc., 401 F.3d 1233, 1239 (11th Cir.2005) (classifying personal injury actions arising from pharmaceutical use as kind of toxic tort case in which the medical community does not generally recognize toxicity of agent); see also Leathers v. Pfizer, Inc., 233 F.R.D. 687, 690 (N.D.Ga.2006). However, the relationship between toxic tort and products liability law is not exactly the issue before us. The issue is whether the toxic dose showing required in environmental exposure actions is applicable to products liability claims for allegedly toxic drugs.

Defendants cite a lengthy list of cases in support of their argument that products liability claims about the toxicity of drugs require evidence of a toxic dose. See Reply at 15. However, only two of these decisions involve medicine. First, in McClain v. Metabolife Intern., Inc., 401 F.3d 1233, 1236 (11th Cir.2005), plaintiffs alleged they sustained “serious injuries after taking Metabolife 356, an herbal appetite suppressant containing ephedrine and caffeine.” The court categorized the action as a toxic tort case in which the medical community does not “generally recognize the agent as both toxic and causing the injury plaintiff alleges,” as distinguished from actions involving known toxins like asbestos and cigarette smoke. Id. at 1239. The court excluded a scientific expert's opinion in part because he could not “provide any opinions about the general dose-response levels for Metabolife's toxicity.” Id. at 1241. In toxic tort cases, the court concluded, “scientific...