ViroPharma Announces Positive CHMP Opinion for Cinryze(R) (C1 Inhibitor [Human]) in European Union

Approval Recommended for Three Indications: Routine Prevention, Pre- Procedure Prevention, and Treatment in Patients with Hereditary Angioedema (HAE) -

EXTON, Pennsylvania, March 18, 2011 - ViroPharma Incorporated (Nasdaq: VPHM) today announced that the Committee
for Medicinal Products for Human Use (CHMP) of the European Medicines Agency
(EMA) has adopted a positive opinion at its plenary meeting in March 2011
recommending approval of a Centralized Marketing Authorization for Cinryze(R)
(C1 inhibitor [human]) in adults and adolescents with hereditary angioedema
(HAE) for routine prevention, pre-procedure prevention and acute treatment of
angioedema attacks. The recommendation includes a self administration option
for appropriately trained patients included in the proposed Summary of
Product Characteristics.

Specifically, the CHMP-recommended the approved therapeutic indication to
include treatment and pre-procedure prevention of angioedema attacks in
adults and adolescents with hereditary angioedema (HAE), and routine
prevention of angioedema attacks in adults and adolescents with severe and
recurrent attacks of hereditary angioedema (HAE), who are intolerant to or
insufficiently protected by oral prevention treatments or patients who are
inadequately managed with repeated acute treatment. The CHMP also notes the
relationship between Sanquin and ViroPharma, and that Sanquin's C1 inhibitor,
Cetor, is approved in a limited number of member states for acute treatment
which is one of the three indications recommended for Cinryze, as an
outstanding issue that must be considered by the European Commission prior to
approval of the Cinryze Marketing Authorization Application.

"This would be the first C1-inhibitor therapy to be approved in Europe
for prevention of HAE attacks in patients with hereditary angioedema,"
commented Dr. Emel Aygoren-Pursun, Universitatsklinik (University Hospital),
Frankfurt. "Prophylactic therapy with C1-inhibitor concentrate is an
important step forward in the management of severely affected HAE patients.
It is also beneficial that this C1-inhibitor therapy is also to be approved
for therapy of acute attacks and pre-procedure prevention."

"This positive CHMP opinion marks a key step in making Cinryze available
to HAE patients across Europe and beyond that choose to proactively address
their disease," commented Thierry Darcis, M.D., ViroPharma's vice president,
general manager, Europe. "We estimate that there are several thousand
patients throughout Europe who suffer from this debilitating disease, and
with this recommendation, these patients may soon benefit from the unique use
of Cinryze to either prevent their attacks or treat them when they occur,
with the added convenience of self administration after appropriate training.
ViroPharma is committed to providing important medicines to patients with
unmet medical needs, and we look forward to working closely with physicians
across Europe toward this important goal."

The CHMP is the scientific advisory body of the EMA responsible for
reviewing Marketing Authorization Applications for medicinal products for
human use. The CHMP positive opinion forms the scientific basis for the
European Commission to issue a binding decision for a Centralized Marketing
Authorization, once issued, is valid throughout all the Member States of the
European Union (EU) as well as in the European Economic Area (EEA), namely
Norway, Iceland and Liechtenstein. The anticipated timeframe for the European
Commission decision is in the second quarter of 2011. A summary of the CHMP
opinion will be available here: tinyurl.com/2am4ubc. Please select "C"
to access the Cinryze summary opinion.

Continued Darcis, "Our work is already well underway towards preparing
for our commercial launch in Europe, with the goal of making this important
therapeutic product available to European patients as soon as possible."

Cinryze was designated an orphan medicinal product on October 8, 2009.
Upon granting of a Centralized Marketing Authorization and retention of the
orphan medicinal product designation, Cinryze would be entitled to a period
of 10 years market exclusivity in respect of the approved therapeutic
indication. This 10-year market exclusivity period could be extended
cumulatively to 12 years when the results of all studies conducted in
compliance with an agreed pediatric investigation plan are completed and
included in the summary of product characteristics.

About Cinryze(R) (C1 esterase inhibitor [human])

Cinryze is a highly purified, pasteurized and nanofiltered plasma-derived
C1 esterase inhibitor product. In the U.S., Cinryze was approved by FDA for
routine prophylaxis against angioedema attacks in adolescent and adult
patients with HAE. In the E.U., the recommended indication is for treatment
and pre-procedure prevention of angioedema attacks in adults and adolescents
with hereditary angioedema (HAE), and routine prevention of angioedema
attacks in adults and adolescents with severe and recurrent attacks of
hereditary angioedema (HAE), who are intolerant to or insufficiently
protected by oral prevention treatments or patients who are inadequately
managed with repeated acute treatment.

Severe hypersensitivity reactions to Cinryze may occur. Thrombotic events
have occurred in patients receiving Cinryze for routine prophylaxis, and in
patients receiving off-label high dose C1 inhibitor therapy. Monitor patients
with known risk factors for thrombotic events. With any blood or plasma
derived product, there may be a risk of transmission of infectious agents,
e.g. viruses and, theoretically, the CJD agent. The risk has been reduced by
screening donors for prior exposure to certain virus infections and by
manufacturing steps to reduce the risk of viral transmission including
pasteurization and nanofiltration.

The most common adverse reactions observed have been upper respiratory
infection, sinusitis, rash and headache. No drug-related serious adverse
events (SAEs) have been observed in clinical trials.

Cinryze is for intravenous use only. Per the U.S. label, a dose of 1000
Units of Cinryze can be administered every 3 or 4 days for routine
prophylaxis against angioedema attacks in HAE patients. Cinryze is
administered at an injection rate of 1 mL per minute.

About Hereditary Angioedema (HAE)

HAE is a rare, severely debilitating, life-threatening genetic disorder
caused by a deficiency of C1 inhibitor, a human plasma protein. This
condition is the result of a defect in the gene controlling the synthesis of
C1 inhibitor. C1 inhibitor maintains the natural regulation of the contact,
complement, and fibrinolytic systems, that when left unregulated, can
initiate or perpetuate an attack by consuming the already low levels of
endogenous C1 inhibitor in HAE patients. Patients with C1 inhibitor
deficiency experience recurrent, unpredictable, debilitating, and potentially
life threatening attacks of inflammation affecting the larynx, abdomen, face,
extremities and urogenital tract. Patients with HAE experience approximately
20 to 100 days of incapacitation per year. There are estimated to be at least
6,500 people with HAE in the United States and approximately similar
demographics in the European Union.

For more information on HAE, visit the U.S. HAE Association's website at:
www.haea.org or the HAEi (International Patient Organization for C1
Inhibitor Deficiencies) at www.haei.org.

About ViroPharma Incorporated

ViroPharma Incorporated is an international biopharmaceutical company
committed to developing and commercializing innovative products for physician
specialists to enable the support of patients with serious diseases for which
there is an unmet medical need, and providing rewarding careers to employees.
ViroPharma commercializes Cinryze(R) (C1 esterase inhibitor [human]) in the
U.S. for routine prophylaxis against angioedema attacks in adolescent and
adult patients with hereditary angioedema (HAE). ViroPharma commercializes
Vancocin(R), approved in the U.S. for oral administration for treatment of
antibiotic-associated pseudomembranous colitis caused by Clostridium
difficile and enterocolitis caused by Staphylococcus aureus, including
methicillin-resistant strains (for prescribing information on ViroPharma's
commercial products, please download the package inserts at
www.viropharma.com/Products.aspx). ViroPharma currently focuses its
drug development activities in diseases including C1 esterase inhibitor
deficiency and C. difficile infection.

ViroPharma routinely posts information, including press releases, which
may be important to investors in the investor relations and media sections of
our company's website, www.viropharma.com/. The company encourages
investors to consult these sections for more information on ViroPharma and
our business.

Forward Looking Statements

Certain statements in this press release contain forward-looking
statements that involve a number of risks and uncertainties. Forward-looking
statements provide our current expectations or forecasts of future events,
including our regulatory filings in Europe related to Cinryze, including
without limitation statements related to potential regulatory timelines, the
likelihood of regulatory success including our ability to address the
questions regarding our relationship with Sanquin and the scope of
indications for which Cinryze may be approved. The EC may view the data
regarding the use of Cinryze for acute treatment and / or prevention of HAE
we have submitted in the MAA as insufficient or inconclusive, request
additional data, require additional clinical studies, delay any decision past
the time frames anticipated by us, limit any approved indications, deny the
approval of Cinryze for acute treatment and / or prevention of HAE or approve
a competing product which has been granted orphan drug designation thereby
preventing Cinryze from reaching the European market. In addition, the EMEA
has enacted orphan drug legislation and Cinryze has received an orphan drug
designation under this legislation. The EMA must reconfirm the orphan
designation in connection with the approval of an MAA. These factors, and
other factors, including, but not limited to those described in our annual
report on Form 10-K for the year ended December 31, 2010 filed with the
Securities and Exchange Commission, could cause future results to differ
materially from the expectations expressed in this press release. The
forward-looking statements contained in this press release are made as of the
date hereof and may become outdated over time. ViroPharma does not assume any
responsibility for updating any forward-looking statements. These forward
looking statements should not be relied upon as representing our assessments
as of any date subsequent to the date of this press release.

Robert A. Doody, Assistant Director, Investor Relations, +1-610-321-6290, or Kristina M. Broadbelt (Media), Associate Director, PR & Advocacy, +1-610-321-2358