UNITED STATES

SECURITIES AND EXCHANGE
COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Item 2. Identity and Background

Item 5. Interest in Securities of the Issuer

SIGNATURE

This Amendment No. 5 to Schedule 13D (this “Amendment”) amends and supplements the Schedule 13D filed by Endo Pharma LLC, a limited liability company organized under the laws of the State of Delaware (“Endo LLC”), and the other reporting persons named therein with the Securities Exchange Commission (“SEC”) on July 17, 2000, as amended by Amendment No. 1 filed with the SEC on February 11, 2003, as amended by Amendment No. 2 filed with the SEC on September 22, 2005, as amended by Amendment No. 3 filed with the SEC on October 17, 2005, as amended by Amendment No. 4 filed with the SEC on January 26, 2006 (together, the “Filing”), with respect to the common stock, par value $.01 per share (the “Common Stock”), of Endo Pharmaceuticals Holdings Inc. (the “Issuer” or “Endo” ). Capitalized terms used herein which are not defined herein have the meanings given to them in the Filing. The main purpose of this Amendment is to amend and supplement the information contained in Items 2 and 5 of the Filing. Except as set forth below, all previous Items of the Filing remain unchanged.

Item 1.

Security and Issuer

Item 2.

Identity and Background

Item 2(a) is hereby amended and restated as follows:

“(a)  This Schedule 13D is being filed jointly by Endo Pharma LLC, a limited liability company organized under the laws of the State of Delaware ("Endo LLC"); Kelso Investment Associates V, L.P., a limited partnership organized under the laws of the State of Delaware ("KIA V"); Kelso Equity Partners V, L.P., a limited partnership organized under the laws of the State of Delaware ("KEP V"); Kelso Partners V, L.P., a limited partnership organized under the laws of the State of Delaware and the general partner of KIA V ("KP V"); Philip E. Berney, Frank K. Bynum, Jr., James J. Connors, II, Michael B. Goldberg, Frank J. Loverro, George E. Matelich, Frank T. Nickell, David I. Wahrhaftig, and Thomas R. Wall, IV, each of whom is a general partner of KP V and of KEP V (such individuals, collectively, the "Kelso General Partners")  (Endo LLC, KIA V, KEP V, KP V, the Kelso General Partners, are referred to herein as the "Filing Persons").  Joseph S. Schuchert retired and is no longer a general partner of KP V and KEP V effective February 28, 2006.  The Filing Persons, other than Endo LLC, hereby disclaim beneficial ownership of any shares of the Common Stock that may be beneficially owned by Endo LLC, and the filing of this statement shall not be construed as an admission that the Filing Persons, other than Endo LLC, are, for purposes of Section 13(d) of the Exchange Act, the beneficial owners of any such shares of Common Stock.  Information with respect to each Filing Person is given solely by such Filing Person and no Filing Person has responsibility for the accuracy or completeness of information supplied by any other Filing Person.”

The second paragraph of Item 2(c) is hereby amended and restated as follows:

“KIA V and KEP V are private investment vehicles formed for the purpose of investing in transactions arranged by Kelso & Company, a private investment firm specializing in acquisition transactions ("Kelso").  The present principal occupation of each of the Kelso General Partners is as follows:  Mr. Nickell is President and Chief Executive Officer of Kelso; Mr. Berney is Managing Director of Kelso; Mr. Bynum is Managing Director of Kelso; Mr. Connors is Managing Director and General Counsel of Kelso; Mr. Goldberg is Managing Director of Kelso; Mr. Loverro is Managing Director of Kelso; Mr. Matelich is Managing Director of Kelso; Mr. Wall is Managing Director of Kelso and Mr. Wahrhaftig is Managing Director of Kelso.” 

Item 3.

Source and Amount of Funds or Other Consideration

Item 4.

Purpose of Transaction

Item 5.

Interest in Securities of the Issuer

Item 5(a)-(b) is hereby amended and restated in its entirety to read as follows:

“Endo LLC

As of March 1, 2006, the aggregate number of shares of Common Stock that Endo LLC has the sole power to vote or to direct the vote of (and as a result, may, under Rule 13d-3 under the Exchange Act, be deemed the beneficial owner of) is 10,619,715.  This represents approximately 8.0% of the 132,922,980 shares of Common Stock outstanding as of March 1, 2006.

All Other Filing Persons

Because of their direct or indirect ownership of the majority of the Units of Endo LLC, each of KIA V, KEP V, KP V and the Kelso General Partners may be deemed as possessing the shared power to vote or to direct the vote (and as a result, may under Rule 13d-3 under the Exchange Act, be deemed the beneficial owner of) an aggregate of 8,879,658 shares of Common Stock (8,190,481 shares of Common Stock in the case of KP V).  This number of shares represents approximately 6.7% (6.2% in the case of KP V) of the 132,922,980 shares of such Common Stock outstanding as of March 1, 2006. However, all such Filing Persons, other than Endo LLC, disclaim beneficial ownership of such shares of Common Stock.”

Item 5(c) is hereby amended by adding the following after the last paragraph under "Endo LLC Common Stock Sales":

On February 17, 2006, Endo LLC, in satisfaction of its contractual obligations under certain equity plans, transferred 2,500 shares of Common Stock held by it to certain employees of the Issuer in connection with the exercise of options held by such employees. 

On February 23, 2006, Endo LLC, in satisfaction of its contractual obligations under certain equity plans, transferred 3,000 shares of Common Stock held by it to certain employees of the Issuer in connection with the exercise of options held by such employees. 

On February 27, 2006, Endo LLC, in satisfaction of its contractual obligations under certain equity plans, transferred 4,528 shares of Common Stock held by it to certain employees of the Issuer in connection with the exercise of options held by such employees. 

On March 1, 2006, Endo LLC, in satisfaction of its contractual obligations under certain equity plans, transferred 2,027 shares of Common Stock held by it to certain employees of the Issuer in connection with the exercise of options held by such employees. 

Item 6.

Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer

Item 7.

Material to Be Filed as Exhibits

ENDO PHARMA LLC

By:

/s/ JEFFREY R. BLACK

Name: Jeffrey R. Black

Title: Chief Financial Officer

KELSO INVESTMENT ASSOCIATES V, L.P.

BY: Kelso Partners V, L.P., its General Partner

By:

/s/ JAMES J. CONNORS, II

General Partner

KELSO EQUITY PARTNERS V, L.P.

By:

/s/ JAMES J. CONNORS, II

General Partner

KELSO PARTNERS V, L.P.

By:

/s/ JAMES J. CONNORS, II

General Partner

*

Philip E. Berney

*

Frank K. Bynum, Jr.

/s/ JAMES J. CONNORS, II

James J. Connors, II

*

Michael B. Goldberg

*

Frank J. Loverro

*

George E. Matelich

*

Frank T. Nickell

*

David I. Wahrhaftig

*

Thomas R. Wall, IV

By:

/s/ JAMES J. CONNORS, II

James J. Connors, II

Attorney-in-Fact

Exhibit

Description

 1.*

Form of Exchange Agreement, by and between Endo Pharmaceuticals Holdings Inc. (“Endo”) and the stockholders party thereto

 2.*

Endo Warrant, dated as of July 17, 2000, issued by Endo to Endo Pharma LLC (“Endo LLC”)

 3.*

Pre-Merger Warrant Agreement, dated as of July 17, 2000, by and between Endo and United States Trust Company of New York, as warrant agent

 4.*

Letter Agreement, dated as of November 26, 1999, by and among Algos Pharmaceutical Corporation, Endo, Kelso Investment Associates V, L.P. (“KIA V”) and Kelso Equity Partners V, L.P. (“KEP V”)

 5.*

Limited Liability Company Agreement of Endo LLC, dated as of July 14, 2000, by and among the persons party thereto and each of their Permitted Transferees (as defined therein)

 6.*

Amended and Restated Executive Stockholders Agreement, dated as of July 14, 2000, by and among Endo, Endo LLC, KIA V, KEP V and the Management Stockholders (as defined therein)

 7.*

Amended and Restated Employee Stockholders Agreement, dated as of July 14, 2000, by and among Endo, Endo LLC, KIA V, KEP V and the Employee Stockholders (as defined therein)

 8.*

Endo Pharma LLC Amended and Restated 1997 Employee Stock Option Plan

 9.*

Endo Pharma LLC Amended and Restated 1997 Executive Stock Option Plan

10.*

Endo Pharma LLC 2000 Supplemental Employee Option Plan

11.*

Endo Pharma LLC 2000 Supplemental Executive Option Plan

12.*

Tax Sharing Agreement, dated as of July 17, 2000, by and among Endo, Endo Inc. and Endo LLC

13.*

Treasury Agreement, dated as of July 17, 2000, by and between Endo and Endo LLC

14.*

Registration Rights Agreement, dated as of July 17, 2000, by and between Endo and Endo LLC

15.*

Joint Filing Agreement, dated as of July 26, 2000

16.*

Powers of Attorney

17.**

Amended and Restated Employee Stockholders Agreement, dated June 5, 2003, by and among Endo, Endo LLC, KIA V, KEP V and the Employee Stockholders (as defined therein) (incorporated herein by reference to Exhibit 10.2 of Amendment No. 2 to the Form S-3 Registration Statement (Registration No. 333-105338) filed by Endo with the Commission on July 1, 2003)

18.**

Amendment to the Registration Rights Agreement, dated June 30, 2003, by and between Endo and Endo LLC (incorporated herein by reference to Exhibit 10.1 of Amendment No. 2 to the Form S-3 Registration Statement (Registration No. 333-105338) filed by Endo with the Commission on July 1, 2003)

19.**

Amended and Restated Executive Stockholders Agreement, dated July 7, 2003, by and among Endo, Endo LLC, KIA V, KEP V and certain Amending Stockholders (as defined therein) (incorporated herein by reference to Exhibit 4.1 of Form 10Q for the Quarter ended June 30, 2003, filed by Endo with the Commission on August 14, 2003)

20.**

Shelf Registration Agreement, dated April 30, 2004, by and between Endo and Endo LLC (incorporated herein by reference to Exhibit 10.2 of Amendment No. 1 to the Form S-3 Registration Statement (Registration No. 333-115032) filed by Endo with the Commission on June 10, 2004)

21.**

Amended and Restated Tax Sharing Agreement, dated April 30, 2004, by and among Endo, Endo Pharmaceuticals Inc (f/k/a Endo Inc.) and Endo LLC (incorporated herein by reference to Exhibit 10.6 of Form 10Q for the Quarter ended March 31, 2004, filed by Endo with the Commission on May 10, 2004)

22.**

Amendment to the Shelf Registration Agreement, dated June 10, 2004, by and between Endo and Endo LLC (incorporated herein by reference to Exhibit 10.3 of Amendment No. 1 to the Form S-3 Registration Statement (Registration No. 333-115032) filed by Endo with the Commission on June 10, 2004)

23.**

Amendment to the Amended and Restated Employee Stockholders Agreement, dated June 28, 2004, by and among Endo, Endo LLC, KIA V, KEP V and certain Amending Stockholders (as defined therein) (incorporated herein by reference to Exhibit 4.2 of Form 10Q for the Quarter ended September 30, 2004, filed by Endo with the Commission on November 5, 2004)

24.**

Amendment to the Amended and Restated Executive Stockholders Agreement, dated June 28, 2004, by and among Endo, Endo LLC, KIA V, KEP V and certain Amending Stockholders (as defined therein) (incorporated herein by reference to Exhibit 4.1 of Form 10Q for the Quarter ended September 30, 2004, filed by Endo with the Commission on November 5, 2004)

25.**

Consent and Release, dated September 20, 2005, by and among Endo, Endo LLC, KIA V, KEP V and certain Employee Stockholders (as defined therein) signatory thereto (incorporated herein by reference to Exhibit 99.1 of Form 8-K, filed by Endo with the Commission on September 21, 2005)

26.**

Amendment 2 to the Amended and Restated Employee Stockholders Agreement, dated September 20, 2005, by and among Endo, Endo LLC, KIA V, KEP V and certain Amending Stockholders (as defined therein) (incorporated herein by reference to Exhibit 99.2 of Form 8-K, filed by Endo with the Commission on September 21, 2005)

27.**

Amendment 2 to the Amended and Restated Executive Stockholders Agreement, dated September 20, 2005, by and among Endo, Endo LLC, KIA V, KEP V and certain Amending Stockholders (as defined therein) (incorporated herein by reference to Exhibit 99.3 of Form 8-K, filed by Endo with the Commission on September 21, 2005)

28.**

Shelf Registration Agreement, dated September 21, 2005, by and between Endo, Endo LLC and certain Stockholders (as defined therein) (incorporated herein by reference to Exhibit 99.4 of Form 8-K, filed by Endo with the Commission on September 21, 2005)

29.***

Shelf Registration Agreement, dated January 19, 2006, by and between Endo, Endo LLC and certain Stockholders (as defined therein) (incorporated herein by reference to Exhibit 10.50 of Form 8-K, filed by Endo with the Commission on January 23, 2006)