United States District Court, E.D. Pennsylvania
action, Plaintiff Samuel Woniewala claims that MiraLAX®,
an over-the-counter laxative, failed to warn the medical
community about the risks associated with the product, which
allegedly caused him to develop oxalate nephropathy, an acute
renal injury characterized by calcium oxalate deposits in the
kidneys. (Doc. Nos. 49 at ¶ 7; 74 at 8.) As a result of
this injury, Plaintiff will require continued treatment and
potentially a kidney transplant. (Doc. No. 74 at 8.) To
support these claims, he seeks to admit the testimony of two
causation experts: his nephrologist and a renal pathologist.
A nephrologist is a physician who specializes in kidney
function and a renal pathologist is a physician who studies
the development of disease in the kidneys.
move to preclude the testimony of these witnesses, relying on
Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579
(1993), and Fed.R.Evid. 702 (Testimony By Expert Witness)
(Doc. Nos. 67 and 76.) On May 10, 2017, the Court held a
hearing on Defendants' Motion to Exclude Plaintiff's
Causation Experts. For reasons that follow, the Court finds
that Plaintiff's Causation Experts are qualified to
testify in this case and that they have opinions which are
the result of reliable methodologies. Accordingly,
Defendants' Motion to Exclude Plaintiff's Causation
Experts (Doc. No. 67) will be denied.
has lived with stable, Stage III chronic kidney disease for
roughly thirteen years. (Doc. Nos. 49 at 4; 74 at 7.) His
disease was managed by his primary care physician, Dr. Karen
Bowles, M.D. and in later years, by a nephrologist, Dr.
Michael Rudnick, M.D.. (Doc. No. 74 at 7.) By July 10, 2009,
his disease was also being monitored by another nephrologist
at the Hospital of the University of Pennsylvania. (Doc. No.
49 at 5.)
in 2009, Plaintiff experienced problems with chronic
constipation. (Id. at 4.) Both his primary care
physician, Dr. Bowles, and his nephrologist, Dr. Rudnick,
prescribed MiraLAX®-an over-the-counter laxative-to treat
Plaintiff's constipation. (Id. at 4-5.) From
2009 until May 2013, Plaintiff continued using MiraLAX®,
as his doctors advised. (Id. at 4-8.) On May 6,
2013, he was hospitalized with an acute kidney injury.
(Id. at 7.) In June 2013, a renal biopsy revealed
that Plaintiff had developed oxalate nephropathy.
(Id.) Oxalate nephropathy is a condition in which
calcium oxalate crystals are deposited in the kidneys,
causing injury. (Doc. No. 67-1 at 9.)
initiated this action alleging claims of negligence, strict
product liability, and breach of express and implied
warranties arising from his use of the laxative MiraLAX®.
(Doc. No. 1-1.) In support of his claims, Plaintiff will
offer at trial the expert testimony of his treating
nephrologist Dr. Michael Rudnick, M.D., renal pathologist Dr.
Glen Markowitz, M.D., and toxicologist Dr. Lawrence H. Lash,
Ph.D. (Doc. No. 74 at 6.) Both Dr. Rudnick and
Dr. Markowitz opine that Plaintiff developed oxalate
nephropathy as a result of his use of MiraLAX®.
(Id.) The active ingredient in MiraLAX® is a
form of polyethylene glycol with a molecular weight of 3350,
referred to as PEG-3350. (Doc. No. 67-1 at 9.) Plaintiff
claims that there is a “clear relationship between
polyethylene glycol and the deposit of calcium oxalate in the
kidneys” (Doc. No. 80 at 30:10-13) and submits that Dr.
Rudnick and Dr. Markowitz will support these claims. The
focal point of the overarching case, therefore, is whether
MiraLAX®'s active ingredient, PEG-3350, caused
Plaintiff's acute kidney injury.
noted, Defendants move to preclude the testimony of the
proffered experts, Dr. Rudnick and Dr. Markowitz. (Doc. No.
67.) Defendants argue that Dr. Rudnick: (1) is not qualified
to offer a “biological plausibility” opinion or a
specific causation opinion, and (2) did not use reliable
methodology in forming his opinions. (Doc. No. 67-1 at
13-28.) Similarly, Defendants argue that Dr. Markowitz: (1)
is not qualified to offer a specific causation opinion, and
(2) did not use reliable methodology in forming his opinions.
(Id. at 28-34.) Relying upon Feit v. Great West
Life & Annuity Ins. Co., 271 F. App'x 246, 254
(3d Cir. 2008), insofar as reliable methodology is concerned,
Defendants claim that the experts improperly employed
differential diagnosis as a methodology because they did not
consider all possible causes of Plaintiff's oxalate
nephropathy and then rule out through the process of
elimination all possible causes, leaving the remaining
potential cause as the most likely cause. Defendants also
challenge the fact that Dr. Markowitz relied on Dr.
Rudnick's report without ever having met Plaintiff and
merely formulated a “piggybacked opinion.” (Doc.
No. 67-1 at 34.)
Dr. Michael Rudnick's Report
Michael Rudnick is Plaintiff's treating nephrologist. His
expert report essentially is comprised of knowledge of his
own treatment and medical records of Plaintiff. In order to
prepare his expert report,  Dr. Rudnick also reviewed the
1. Medical Records of Michael Rudnick, M.D.
2. Medical Records of Karen Bowles, M.D.
3. Admission records at Mercy Hospital 5/6/13
4. Admission records at the Hospital of the University of
5. Deposition of Dr. Sanjeev Sethi
6. Deposition of Samuel Woniewala
7. Deposition of Karen Bowles
(Doc. No. 67-9 at 1.)
Rudnick led a team of physicians to uncover the cause of and
treat Plaintiff's acute kidney injury. (Doc. No. 74 at
7.) He ordered the biopsy of Plaintiff's kidney, which
was sent to the Mayo Clinic in Rochester, Minnesota.
(Id. at 8.) There, Dr. Sanjeev Sethi, the renal
pathologist at the Mayo Clinic, discovered the oxalate
nephropathy and disclosed his findings to Dr. Rudnick.
upon the above information, Dr. Rudnick concluded that
Plaintiff's kidney injury was due to oxalate nephropathy
resulting from his ingestion of MiraLAX®.
Dr. Glen Markowitz's Report
Glen Markowitz is a renal pathologist and a professor of
pathology and cell biology at Columbia University's
College of Physicians and Surgeons. (Doc. No. 74-3.) Dr.
Markowitz has given lectures and has written extensively on
the pathology of drug-induced renal injury. (Id.)
order to prepare his expert report,  Dr. Markowitz reviewed the
1. Deposition transcript, Dr. Sanjeev Sethi
2. Deposition transcript, Samuel Woniewala
3. Expert report of treating nephrologist, Dr. Michael