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                                                                     EXHIBIT 3.1


                      RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                          ENCYSIVE PHARMACEUTICALS INC.

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         Encysive Pharmaceuticals Inc., a corporation organized under the laws
of the State of Delaware, hereby certifies as follows:

         1. The name of the corporation is Encysive Pharmaceuticals Inc. (the
"Corporation") and the name under which the Corporation was originally
incorporated was Cardiology Institute of Texas, Ltd. The date of the filing of
its original Certificate of Incorporation with the Secretary of State was August
2, 1989.

         2. This Restated Certificate of Incorporation only restates and
integrates and does not further amend the provisions of the Certificate of
Incorporation of the Corporation as heretofore amended or supplemented, and
there is no discrepancy between those provisions and the provisions of this
Restated Certificate of Incorporation:

         3. The text of the Certificate of Incorporation as amended or
supplemented heretofore is hereby restated without further amendments or changes
to read as herein set forth in full:

         FIRST: The name of the corporation is Encysive Pharmaceuticals Inc.
(hereinafter referred to as the "Corporation").

         SECOND: The address of the Corporation's registered office in the State
of Delaware is 2711 Centerville Road, Suite 400, City of Wilmington, County of
New Castle. The name of its registered agent at such address is The
Prentice-Hall Corporation System, Inc.

         THIRD: The purpose of the Corporation is to engage in any lawful act or
activity for which corporations may be organized under the General Corporation
Law of Delaware (the "DGCL").

         FOURTH: The total number of shares of all classes of stock which the
Corporation shall have authority to issue is Seventy Five Million (75,000,000)
shares of common stock (hereinafter called "Common Stock"), of a par value of
one-half of one cent ($.005) per share and Five Million (5,000,000) shares of
preferred stock (hereinafter called "Preferred Stock") of a par value of
one-half of one cent ($.005) per share

                  Preferred Stock

                  A. Shares of Preferred Stock may be issued, from time to time,
in one or more series, each of such series to have such voting powers full or
limited or no voting powers, and such designations, preferences, and relative,
participating, optional or other special rights, and qualifications, limitations
or restrictions with respect thereto as are stated and expressed herein, in any
amendment or amendments to this Restated Certificate of Incorporation (the
"Certificate"), or in any resolution or resolutions establishing such series as
are adopted by the board of directors of the Corporation (the "Board") as
hereinafter provided, and as are

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acknowledged, filed and recorded in accordance with the laws of the State of
Delaware and as are not inconsistent with this ARTICLE FOURTH or any other
provisions of the Certificate.

                  B. Authority is hereby expressly granted to the Board, subject
to the provisions of this ARTICLE FOURTH, to authorize the issuance of one or
more series of Preferred Stock and with respect to each series to fix by
resolution or resolutions providing for the issuance of such series:

                  (1) The distinctive designation of such series and the number
                  of shares which shall constitute such series;

                  (2) The amount of the consideration to be received for the
                  shares of such series which shall be capital;

                  (3) The cumulative or noncumulative nature of the dividend to
                  be paid;

                  (4) The dividend rate or rates to which such shares shall be
                  entitled and the restrictions, limitations and conditions upon
                  the payment of such dividends, the date or dates from which
                  such dividends, if declared, shall be payable, and whether
                  arrearages on the payment of dividends will bear interest;

                  (5) Whether or not the shares of such series shall be
                  redeemable; the limitations and restrictions with respect to
                  such redemptions (including whether or not the shares of such
                  series shall be redeemable at the option of either the holder
                  or the Corporation or upon the happening of a specified
                  event); the manner of selecting shares of such series for
                  redemption if less than all the shares are to be redeemed; the
                  amount, if any, in addition to any accrued dividends thereon
                  which the holder of shares of such series shall be entitled to
                  receive upon the redemption thereof, which amount may vary at
                  different redemption dates, may be subject to adjustment and
                  may be different with respect to shares redeemed through the
                  operation of any purchase, retirement or sinking fund and with
                  respect to shares otherwise redeemed; and whether or not the
                  shares of such series, if redeemable, shall be redeemable for
                  cash, property or rights, including securities of any other
                  corporation;

                  (6) The amount which the holders of shares of such series may
                  be entitled to receive in addition to any accumulated
                  dividends upon the voluntary or involuntary liquidation or
                  dissolution of the Corporation, which amount may vary
                  depending upon whether such liquidation or dissolution is
                  voluntary or involuntary and, if voluntary, may vary at
                  different dates; provided, however, that the merger or
                  consolidation of the Corporation or a sale, lease, or
                  conveyance of all or part of the assets of the Corporation
                  shall not be deemed a liquidation or dissolution;

                  (7) Whether or not the shares of such series shall be subject
                  to the operation of a purchase, retirement or sinking fund,
                  and if so, whether such purchase, retirement or sinking fund
                  shall be cumulative or noncumulative, and the extent to and
                  the manner in which such funds shall be applied to the
                  purchase or

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                  redemption of the share of such series for retirement or to
                  the other corporate purposes and the terms and provisions
                  relative to the operation of said fund or funds;

                  (8) Whether or not the shares of such series shall be
                  convertible into, or exchangeable for, shares of stock of any
                  other class or classes, or of any other series of the same
                  class, and if so convertible or exchangeable, the price or
                  prices or the rate or rates of conversion or exchange and the
                  method, if any, of adjusting the same;

                  (9) The voting rights, if any, of such series, but not to
                  exceed one vote per share, and whether such voting rights
                  shall be contingent upon the happening of a specified event
                  and whether such voting rights shall cease upon the happening
                  of a specified event; and

                  (10) Any other preferences and relative, participating,
                  optional or other special rights, and qualifications,
                  limitations or restrictions thereof not inconsistent with this
                  ARTICLE FOURTH or any other provision of the Certificate.

                  C. The Board also shall have authority to change the
designation of shares, or the relative rights, preferences and limitations of
the shares of any theretofore established series of Preferred Stock, no share of
which has been issued, and further, the Board shall have authority to increase
or decrease the number of shares of any series previously determined by it
(provided, however, that the number of shares of any series shall not be
decreased to a number less than that of the shares of that series then
outstanding).

                  D. Description of Series A Junior Participating Preferred
                  Stock

                  (1) Designation and Amount. The shares of such series shall be
                  designated as "Preferred Stock - Junior Participating Series
                  A" (the "Series A Preferred Stock") and the number of shares
                  constituting the Series A Preferred Stock shall be 10,000.
                  Such number of shares may be increased or decreased by
                  resolution by the Board and without stockholder action;
                  provided, however, that no decrease shall reduce the number of
                  shares of Series A Preferred Stock to a number less than the
                  number of shares then outstanding plus the number of shares
                  reserved for issuance upon the exercise of outstanding
                  options, rights or warrants upon the conversion of any
                  outstanding securities issued by the Corporation convertible
                  into Series A Preferred Stock, including (without limitation)
                  that certain Rights Agreement dated as of January 2, 2002 (the
                  "Rights Agreement") to which the Corporation is a party.

                  (2) Dividends and Distributions. (a) Subject to the prior
                  dividend rights of the holders of shares of any (i) other
                  series of Preferred Stock or (ii) other class of capital
                  stock, whether now existing or hereafter created (other than
                  the Common Stock), which does not by its express terms rank on
                  a parity with or subordinate to the Series A Preferred Stock
                  with respect to payment of dividends, the holders of Series A
                  Preferred Stock shall be entitled to receive dividends when,
                  as and if

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                  declared from time-to-time by the Board, out of any funds
                  legally available for that purpose; provided, however, that no
                  dividend shall be declared or paid on the Common Stock (other
                  than in shares of Common Stock) unless a dividend shall be
                  simultaneously declared and paid on each share of outstanding
                  Series A Preferred Stock in an amount equal to 1,000 times
                  (subject to adjustment as set forth below) the amount of the
                  dividend then declared and paid on each share of Common Stock.
                  In the event the Corporation shall at any time following the
                  initial issuance of Series A Preferred Stock declare or pay
                  any dividend on the Common Stock payable in shares of Common
                  Stock, or effect a subdivision or combination or consolidation
                  of the outstanding shares of Common Stock (by reclassification
                  or otherwise than by payment of a dividend in shares of Common
                  Stock) into a greater or lesser number of shares of Common
                  Stock, then in each such case the amount to which each share
                  of Series A Preferred Stock was entitled immediately prior to
                  such event to receive pursuant to the preceding sentence shall
                  be adjusted by multiplying such amount by a fraction, the
                  numerator of which is the number of shares of Common Stock
                  outstanding immediately after such event and the denominator
                  of which is the number of shares of Common Stock that were
                  outstanding immediately prior to such event.

                           (b) The provisions of this Section (D) (2) shall not
                  apply to any dividend or other distribution which shall be
                  directly or indirectly in furtherance of any plan of
                  liquidation, whether or not the same shall have been approved
                  by stockholders.

                  (3) Voting Rights. In addition to any other voting rights
                  required by law, the holders of shares of Series A Preferred
                  Stock shall have the following voting rights:

                           (a) Subject to the provisions for adjustment
                  hereinafter set forth, each share of Series A Preferred Stock
                  shall entitle the holder thereof to 1,000 votes (and each one
                  one-thousandth (1/1,000th) of a share of Series A Preferred
                  Stock shall have one vote) on all matters submitted to a vote
                  of the stockholders of the Corporation. In the event the
                  Corporation shall at any time following the initial issuance
                  of Series A Preferred Stock declare or pay any dividend on the
                  Common Stock payable in shares of Common Stock, or effect a
                  subdivision or combination or consolidation of the outstanding
                  shares of Common Stock (by reclassification or otherwise than
                  by payment of a dividend in shares of Common Stock) into a
                  greater or lesser number of shares of Common Stock, then in
                  each such case the number of votes per share to which holders
                  of shares of Series A Preferred Stock were entitled
                  immediately prior to such event shall be adjusted by
                  multiplying such number by a fraction the numerator of which
                  is the number of shares of Common Stock outstanding
                  immediately after such event and the denominator of which is
                  the number of shares of Common Stock that were outstanding
                  immediately prior to such event.

                           (b) Except as otherwise provided herein or by law,
                  the holders of shares of Series A Preferred Stock and the
                  holders of shares of Common Stock

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                  shall vote together as one class on all matters submitted to a
                  vote of stockholders of the Corporation, including, without
                  limitation, the election of directors. If the holders of the
                  Common Stock shall be entitled to cumulate their votes at any
                  election of directors, or upon any other matter, the holders
                  of the Series A Preferred Stock shall also be entitled to
                  cumulative voting at such election of directors or upon such
                  other matter. If cumulative voting shall ever be denied to the
                  holders of the Common Stock, the holders of the Series A
                  Preferred Stock shall similarly cease to be entitled to
                  cumulative voting, without any further action or consent by
                  the holders of Series A Preferred Stock.

                           (c) Except as otherwise set forth herein, holders of
                  Series A Preferred Stock shall have no special voting rights
                  and their consent shall not be required (except to the extent
                  they are entitled to vote with holders of Common Stock as set
                  forth herein) for taking any corporate action.

                  (4) Certain Restrictions. (a) Whenever dividends or
                  distributions payable on the Series A Preferred Stock as
                  provided in Section D (2) are in arrears, thereafter and until
                  all accrued and unpaid dividends and distributions, on shares
                  of Series A Preferred Stock outstanding shall have been paid
                  in full, the Corporation shall not:

                                    (i) declare or pay dividends on, make any
                           other distributions on, or redeem or purchase or
                           otherwise acquire for consideration any shares of
                           stock ranking junior (either as to dividends or upon
                           liquidation, dissolution or winding up) to the Series
                           A Preferred Stock;

                                    (ii) declare or pay dividends on or make any
                           other distributions on any shares of stock ranking on
                           a parity (either as to dividends or upon liquidation,
                           dissolution or winding up) with the Series A
                           Preferred Stock, except dividends paid ratably on the
                           Series A Preferred Stock and all such parity stock on
                           which dividends are payable or in arrears in
                           proportion to the total amounts to which the holders
                           of all such shares are then entitled;

                                    (iii) redeem or purchase or otherwise
                           acquire for consideration shares of any stock ranking
                           on a parity (either as to dividends or upon
                           liquidation, dissolution or winding up) with the
                           Series A Preferred Stock; provided, however, that the
                           Corporation may at any time redeem, purchase or
                           otherwise acquire shares of any such parity stock in
                           exchange for shares of any stock of the Corporation
                           ranking junior (either as to dividends or upon
                           dissolution, liquidation or winding up) to the Series
                           A Preferred Stock; or

                                    (iv) purchase or otherwise acquire for
                           consideration any shares of Series A Preferred Stock,
                           or any shares of stock ranking on a parity with the
                           Series A Preferred Stock, except in accordance with a
                           purchase offer made in writing or by publication (as
                           determined by the Board) to all holders of such
                           shares upon such terms as the Board, after
                           consideration of the respective annual dividend rates
                           and other relative rights and

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                           preferences of the respective Series and classes,
                           shall determine in good faith will result in fair and
                           equitable treatment among the respective series or
                           classes.

                           (b) The Corporation shall not permit any subsidiary
                  of the Corporation to purchase or otherwise acquire for
                  consideration any shares of stock of the Corporation unless
                  the Corporation could, under paragraph (a) of this Section D
                  (4), purchase or otherwise acquire such shares at such time
                  and in such manner.

                  (5) Liquidation Rights. Upon any liquidation, dissolution or
                  winding up of the Corporation, no distribution shall be made
                  (a) to the holders of shares of stock ranking junior (either
                  as to dividends or upon liquidation, dissolution or winding
                  up) to the Series A Preferred Stock unless, prior thereto, the
                  holders of shares of Series A Preferred Stock shall have
                  received $1,000 per share, plus an amount equal to any
                  declared but unpaid dividends thereon, to the date of such
                  payment; provided, however, that the holders of shares of
                  Series A Preferred Stock shall be entitled to receive an
                  aggregate amount per share, subject to adjustment as
                  hereinafter set forth, equal to 1,000 times the aggregate
                  amount to be distributed per share to holders of Common Stock,
                  or (b) to the holders of stock ranking on a parity (either as
                  to dividends or upon liquidation, dissolution or winding up)
                  with the Series A Preferred Stock, except distributions made
                  ratably on the Series A Preferred Stock and all other such
                  parity stock in proportion to the total amounts to which the
                  holders of all such shares are entitled upon such liquidation,
                  dissolution or winding up. In the event the Corporation shall
                  at any time following the initial issuance of Series A
                  Preferred Stock declare or pay any dividend on Common Stock
                  payable in shares of Common Stock, or effect a subdivision or
                  combination or consolidation of the outstanding shares of
                  Common Stock (by reclassification or otherwise than by payment
                  of a dividend in shares of Common Stock) into a greater or
                  lesser number of shares of Common Stock, then in each such
                  case the aggregate amount to which holders of shares of Series
                  A Preferred Stock were entitled immediately prior to such
                  event under the proviso in clause (a) of the preceding
                  sentence shall be adjusted by multiplying such amount by a
                  fraction the numerator of which is the number of shares of
                  Common Stock outstanding immediately after such event and the
                  denominator of which is the number of shares of Common Stock
                  that were outstanding immediately prior to such event.

                  (6) Consolidation, Merger, Etc. In case the Corporation shall
                  enter into any consolidation, merger, combination or other
                  transaction in which the shares of Common Stock are exchanged
                  for or changed into other stock or securities, cash and/or any
                  other property, then in any such case the shares of Series A
                  Preferred Stock shall at the same time be similarly exchanged
                  or changed in an amount per share (subject to the provision
                  for adjustment hereinafter set forth) equal to 1,000 times the
                  aggregate amount of stock, securities, cash and/or any other
                  property, as the case may be, into which or for which each
                  share of Common Stock is changed or exchanged. In the event
                  the Corporation shall at any time following the initial
                  issuance of Series A Preferred Stock declare or pay any
                  dividend on the Common

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                  Stock payable in shares of Common Stock, or effect a
                  subdivision or combination or consolidation of the outstanding
                  shares of Common Stock (by reclassification or otherwise than
                  by payment of a dividend in shares of Common Stock) into a
                  greater or lesser number of shares of Common Stock, then in
                  each such case the amount set forth in the preceding sentence
                  with respect to the exchange or change of shares of Series A
                  Preferred Stock shall be adjusted by multiplying such amount
                  by a fraction the numerator of which is the number of shares
                  of Common Stock outstanding immediately after such event and
                  the denominator of which is the number of shares of Common
                  Stock that were outstanding immediately prior to such event.

                  (7) Ranking. The Series A Preferred Stock shall rank junior
                  with respect to payment of dividends and on liquidation to all
                  other classes and series of Preferred Stock, whether now
                  existing or hereafter created, except any class or series that
                  specifically provides that it shall rank on a parity with or
                  junior to the Series A Preferred Stock.

                  (8) Redemption. The shares of Series A Preferred Stock shall
                  not be redeemable. Notwithstanding the foregoing, the
                  Corporation may acquire shares of Series A Preferred Stock in
                  any other manner permitted by law or the Certificate. The
                  shares of Series A Preferred Stock shall not be subject to or
                  entitled to the operation of a retirement or sinking fund.

                  (9) Fractional Shares. Series A Preferred Stock may be issued
                  in fractions of a share which shall entitle the holder, in
                  proportion to such holder's fractional shares, to exercise
                  voting rights, receive dividends, participate in distributions
                  and have the benefit of all other rights of holders of Series
                  A Preferred Stock. In lieu of fractional shares, the
                  Corporation, prior to the first issuance of a share or a
                  fraction of a share of Series A Preferred Stock, may elect to
                  (a) make a cash payment as provided in the Rights Agreement
                  for fractions of a share other than one one-thousandths
                  (1/1,000ths) of a share or an integral multiple thereof or (b)
                  issue depository receipts evidencing such authorized fraction
                  of a share of Series A Preferred Stock pursuant to an
                  appropriate agreement between the Corporation and a depository
                  selected by the Corporation; provided, however, that such
                  agreement shall provide that the holders of such depository
                  receipts shall have all the rights, privileges and preferences
                  to which they are entitled as holders of the Series A
                  Preferred Stock.

                  (10) Reacquired Shares. Any shares of Series A Preferred Stock
                  purchased or otherwise acquired by the Corporation in any
                  manner whatsoever shall be retired and canceled promptly after
                  the acquisition thereof. All such shares shall upon their
                  cancellation become authorized but unissued shares of
                  Preferred Stock (without designation as to series) and may be
                  reissued as part of a new series of Preferred Stock to be
                  created by resolution or resolutions of the Board, subject to
                  the conditions and restrictions on issuance set forth in the
                  Certificate.

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                  (11) Amendment. The Certificate shall not be amended in any
                  manner which would materially alter or change the powers,
                  preferences or special rights of the Series A Preferred Stock
                  so as to affect them adversely without the affirmative vote of
                  the holders of at least two-thirds of the outstanding shares,
                  if any, of Series A Preferred Stock voting separately as a
                  class.

                  (12) No Other Rights. The Series A Preferred Stock shall not
                  have any relative, participating, optional or other special
                  rights and powers other than as set forth herein and in the
                  Certificate or as provided by law, nor shall the holders
                  thereof have any preemptive right to acquire any shares or
                  securities of any kind, whether now or hereafter authorized,
                  which may at any time be issued, sold or offered for sale by
                  the Corporation.

         FIFTH: The Board is expressly authorized to adopt, amend and repeal the
By-Laws of the Corporation.

         SIXTH: The Corporation shall, to the fullest extent permitted by
Section 145 of the DGCL as the same may be amended or supplemented, indemnify
any and all persons whom it shall have power to indemnify from and against any
and all expenses, liabilities or other matters.

         SEVENTH: A director of the Corporation shall not be liable personally
for breach of his or her fiduciary duties as a director, except that this
article shall not eliminate or limit the liability of a director: (i) for any
breach of his or her duty of loyalty to the Corporation or its stockholders;
(ii) for acts or omissions not in good faith or which involve intentional
misconduct or a knowing violation of the law; (iii) under Section 174 of the
DGCL; or (iv) for any transaction from which he or she derived an improper
personal benefit. No amendment to or repeal of this ARTICLE SEVENTH shall apply
to or have any effect on the liability or alleged liability of any director of
the Corporation for or with respect to any acts or omissions of such director
occurring prior to such amendment.

         EIGHTH: Whenever a compromise or arrangement is proposed between this
Corporation and its creditors or any class of them and/or between this
Corporation and its stockholders or any class of them, any court of equitable
jurisdiction within the State of Delaware may, on the application in a summary
way of this Corporation or of any creditor or stockholder thereof or on the
application of any receiver or receivers appointed for this Corporation under
the provisions of Section 291 of the DGCL or on the application of trustees in
dissolution or of any receiver or receivers appointed for this Corporation under
the provisions of Section 279 of the DGCL order a meeting of the creditors or
class of creditors, and/or of the stockholders or class of stockholders of this
Corporation as the case may be, to be summoned in such manner as the said court
directs. If a majority in number representing three-fourths in value of the
creditors or class of creditors, and/or of the stockholders or class of
stockholders of this Corporation, as the case may be, agree to any compromise or
arrangement and to any reorganization of this Corporation as a consequence of
such compromise or arrangement, the said compromise or arrangement and the said
reorganization shall, if sanctioned by the court to which the said application
has been made, be binding on all the creditors or class of creditors, and/or on
all the stockholders or class of stockholders, of this Corporation, as the case
may be, and also on this Corporation.

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         4. This Restated Certificate of Incorporation was duly adopted by the
Board of Directors in accordance with Sections 242 and 245 of the DGCL.


                            [SIGNATURE PAGE FOLLOWS]

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         IN WITNESS WHEREOF, said Encysive Pharmaceuticals Inc. has caused this
Certificate to be signed by Bruce D. Given, its President and Chief Executive
Officer, this 17th day of September, 2004.



                                            ENCYSIVE PHARMACEUTICALS INC.


                                            /s/ BRUCE D. GIVEN
                                            ----------------------------------
                                            Bruce D. Given, President and
                                            Chief Executive Officer



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