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                                                                  EXHIBIT 10.58

                                    AMENDMENT

                                       TO

                                 LOAN AGREEMENT

         This AMENDMENT TO LOAN AGREEMENT, dated as of March 31, 2000 (the
"Amendment"), is made and entered into by and between Halsey Drug Co., Inc., a
New York corporation ("Borrower"), and Watson Pharmaceuticals, Inc., a Nevada
corporation ("Lender"). Capitalized terms used herein shall have the meanings
given them in the Loan Agreement (as defined below).

                                    Recitals

         WHEREAS, Borrower and Lender are parties to that certain Loan
Agreement, dated as of March 29, 2000 (the "Loan Agreement"); and

         WHEREAS, Borrower and Lender desire to amend certain terms of the Loan
 Agreement;

         NOW, THEREFORE, the parties hereto agree as follows.

                                    Agreement

         1.       Article One of the Loan Agreement is hereby amended in its
entirety to read as follows:

                  "1.   AMOUNT AND TERMS OF LOAN.

                        1.1    Term Loans. Subject to the terms herein, Lender
         agrees to loan to Borrower from time to time the aggregate principal
         amount of Seventeen Million Five Hundred Thousand Dollars ($17,500,000)
         (such take-downs, individually and collectively, the "Loan"). Borrower
         may request take-downs of the Loan hereunder upon five Business Days'
         written notice, such notice to be accompanied by a statement of uses of
         proceeds of past take-downs, if any, and proposed uses of proceeds of
         the take-down being requested. Such statement is for informational
         purposes only. Notwithstanding any prepayment of the Loan by Borrower,
         sums repaid hereunder may not be re-borrowed.

                        1.2   Promissory Note. Borrower's obligation to pay the
         principal of, and interest on, the Loan shall be evidenced by a secured
         promissory note (the "Note"), duly executed and delivered by Borrower,
         such Note to be in the form attached as Exhibit A to the Amendment to
         this Loan Agreement, dated March 31, 2000, by and between Borrower and
         Lender."

         2.       Limitation of Amendment. Except as amended above, the terms
of the Loan Agreement shall remain in full force and effect.

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         3.     Governing Law. This Amendment and the rights of the parties
hereunder shall be governed in all respects by the laws of the State of
California wherein the terms of this Amendment were negotiated.

         4.     Counterparts. This Amendment may be executed in any number of
counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.

         IN WITNESS WHEREOF, Borrower and Lender have caused this Amendment to
be duly executed by their duly authorized officers all as of the day and year
first above written.

"BORROWER"                                        "LENDER"

HALSEY DRUG CO., INC.                             WATSON PHARMACEUTICALS, INC.

/s/ Michael Reicher                               /s/ Robert C. Funsten
By:                                               By:
Its:  Chief Executive Officer                     Its:  Senior Vice President

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                                                                 EXHIBIT 10.59

                         SECURED PROMISSORY NOTE

$17,500,000.00                                           March 31, 2000
                                                         Corona, California

1.   Promise to Pay. For good and valuable consideration, the receipt of which
is hereby acknowledged, HALSEY DRUG CO., INC., a New York corporation,
("Maker"), promises to pay to WATSON PHARMACEUTICALS, INC., a Nevada corporation
("Watson"), or order (either, the "Holder"), on the Maturity Date (as defined
below), unless sooner paid as provided in Section 4 hereof, the principal sum of
Seventeen Million Five Hundred Thousand Dollars ($17,500,000.00), plus accrued
unpaid interest thereon. The outstanding principal balance of this Note shall
bear interest at a variable rate equal to the prime rate announced from time to
time by Bank of America (the "Prime Rate") plus two percent (2.0%) per annum
(the "Interest Rate") from the date such principal amount becomes outstanding to
the date the principal sum is paid in full; provided, however, that if this Note
is not paid in full on the Maturity Date, the unpaid balance of the Note shall
bear interest therefrom and until paid at the Default Rate (as defined below).
Payments of interest shall be due on the each March 31, June 30, September 30
and December 31 during the term of this Note commencing June 30, 2000. All
payments under this Note shall be made to the order of the Holder at 311 Bonnie
Circle, Corona, California, 92880, or such other address as Holder may designate
in writing to Maker, in U.S. dollars, and shall be applied first to accrued
unpaid interest, if any, and then to principal.

2.   Maturity Date. The date that this Note shall mature, and the principal
amount outstanding hereunder, plus accrued unpaid interest thereon and any
charges pertaining thereto, shall become due and payable (the "Maturity Date")
shall be March 31, 2003.

3.   Loan and Security Agreements. Maker and Watson are party to that certain
Loan Agreement, dated as of even date herewith (the "Loan Agreement"), pursuant
to which this Note is being issued. The full and punctual payment and
performance of this Note by Maker are secured and guaranteed by the Company
General Security Agreement, the Company Collateral Assignments, the Stock Pledge
Agreement, the Guaranties, the Guarantors Security Agreement, the Guarantor
Collateral Assignments and the Mortgage, as those terms are defined in the Loan
Agreement (the "Security Agreements"). The security interest granted to Holder
under the Security Agreements extends to the proceeds of any sale or other
transfer or disposition of such assets, whether by Maker, its affiliates, the
Holder or any other person, that occurs prior to the payment in full of this
Note. Copies of the Loan Agreement and the Security Agreements may be obtained
from Maker without charge.

4.   Prepayments. Maker may voluntarily prepay this Note either in whole or in
part without penalty or premium.

5.   Waivers. Maker hereby waives diligence, presentment for payment, demand,
protest, notice of non-payment, notice of dishonor, notice of protest, and any
and all other notices and demands whatsoever. Maker shall remain bound under
this Note until all principal and interest and any other amounts that are
payable hereunder or under the Loan Agreement or the Security Agreements have
been paid in full, notwithstanding any extensions or renewals granted with
respect to this Note or the release of any party liable hereunder or any
security for the payment of this Note. Maker, and any and all endorsers hereof,
also waive the right to plead any and all statutes of limitations as a defense
to any demand on this Note or any and all obligations or liabilities arising out
of or in connection with this Note, the Loan Agreement or the Security
Agreements, to the fullest extent permitted by law.

6.   Events of Default. Any of the following events shall constitute an event of
default by Maker under this Note (an "Event of Default"):

     (a)      the failure of Maker to pay to Holder, on the Maturity Date, any
and all principal amounts due and owing under this Note;

     (b)      the failure of maker to pay to Holder interest payments when due;
or

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      (c)      there occurs any other event or circumstance that constitutes
 an "Event of Default" as defined in Section 8.1 of the Loan Agreement.

Upon the occurrence of any Event of Default, as defined hereinabove, at Holder's
option, Holder may declare immediately due and payable, and on any such
declaration there shall become immediately due and payable, the entire unpaid
principal balance of this Note, together with all accrued and unpaid interest
under this Note and any other sums owing at the time of such declaration
pursuant to this Note, the Loan Agreement or the Security Agreements, and Holder
shall be entitled to exercise all rights and remedies available to Holder under
this Note, under the Loan Agreement and the Security Agreements and under
applicable law, all of which rights and remedies shall be cumulative. Without
limiting the generality of the foregoing, upon the occurrence of an Event of
Default, the interest rate at which interest shall accrue on the principal sum
and any other amounts that are due under this Note shall increase to the lower
of (i) the Prime Rate plus four percent (4.0%) per annum or (ii) the maximum
interest rate permitted under applicable law (the "Default Rate"), until all
such amounts have been paid in full.

7.    No Waiver by Holder. Any delay or omission on the part of Holder to
exercise any of Holder's rights or remedies hereunder, under the Loan Agreement
or the Security Agreements or under applicable law, including, without
limitation, the right to accelerate amounts owing under this Note, shall not be
deemed a waiver of that right or remedy or of any other right or remedy of
Holder in respect thereof. The acceptance by Holder of any payment pursuant to
the terms of this Note which is less than payment in full of all amounts due and
payable at the time of such payment shall not constitute a waiver of the right
to exercise any of the Holder's rights or remedies under this Note, the Loan
Agreement, the Security Agreements or under applicable law at that time or at
any subsequent time or nullify any prior exercise of any such rights or remedies
without the express written consent of Holder, except as and to the extent
provided to the contrary by applicable law.

8.    Governing Law. This Note shall be governed by and construed according to
and enforced under the internal laws of the State of California without giving
effect to its choice of laws rules.

9.    Enforcement of the Note. Maker agrees that the Superior Court in and for
the County of Orange, California shall have exclusive jurisdiction over any
disputes, between the Maker and Holder and any action, suit or other proceeding
brought by Maker or Holder relating to the interpretation or enforcement of this
Note, and Maker agrees as follows: (a) Maker shall accept and not contest the
personal or subject matter jurisdiction of such Court; (b) Maker shall accept
and not object to or challenge the venue of such Court or assert the doctrine of
forum non conveniens with respect to such Court; (c) Maker shall accept and not
contest the validity or effectiveness of service of process in any such action,
suit or other proceeding by registered or certified first class mail; and (d) TO
THE MAXIMUM EXTENT PERMITTED BY LAW, MAKER WAIVES AND SHALL WAIVE ANY RIGHT TO A
TRIAL BY JURY IN ANY ACTION OR OTHER PROCEEDING BROUGHT WITH RESPECT TO THIS
NOTE OR ITS ENFORCEMENT OR INTERPRETATION. If Maker fails to pay any amounts due
hereunder when due, or if an Event of Default occurs, then Maker shall pay all
costs of enforcement and collection, including, without limitation, reasonable
attorneys' fees and costs incurred by Holder, whether or not enforcement and
collection includes the filing of a lawsuit, and whether or not that lawsuit is
prosecuted to judgment. The costs of enforcement and collection shall be added
to the principal amount of the Note and shall accrue interest at the Default
Rate from the date incurred by Holder to the date paid by Maker.

10.   Binding Nature. The provisions of this Note shall be binding on Maker and
shall inure to the benefit of the Holder.

11.   Usury Savings Provisions. In the event Holder receives any sums under this
Note which constitute interest in an amount in excess of that permitted by any
applicable law, then, all such sums constituting interest in excess of that
permitted to be paid under applicable law shall, at Holder's option, either be
credited to the payment of principal owing hereunder or returned to Maker. The
provisions of this Section 11 control the other provisions of this Note and any
other agreement between Maker and Holder.

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12.  Severability. If, but only to the extent that, any provision of this Note
shall be invalid or unenforceable, then, such offending provision shall be
deleted from this Note, but only to the extent necessary to preserve the
validity and effectiveness of this Note to the fullest extent permitted by
applicable law.

13.  Interpretation. No provision of this Note shall be interpreted for or
against Maker or Holder because that person or that person's legal
representative drafted such provision. Unless otherwise indicated elsewhere in
this Note, (a) the term "or" shall not be exclusive, (b) the term "including"
shall mean "including, but not limited to," and (c) the terms "below," "above,"
"herein," "hereof," "hereto," "hereunder" and other terms similar to such terms
shall refer to this Note as a whole and not merely to the specific section,
subsection, paragraph or clause where such terms may appear. The section and
sub-section headings in this Note are included for convenience of reference only
and shall be ignored in the construction or interpretation of this Note.

                                                 "MAKER"

                                                 HALSEY DRUG CO., INC.

                                                 /s/ Michael Reicher
                                                 By:
                                                 Its:  Chief Executive Officer

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