Exhibit 99.1 AGREEMENT AND PLAN OF MERGER BY AND AMONG McKESSON CORPORATION PATRIOT ACQUISITION CORP. a wholly owned direct subsidiary of McKesson CorporationAgreement and Plan of Merger • September 24th, 1997 • Amerisource Distribution Corp • Wholesale-drugs, proprietaries & druggists' sundries • Delaware
Exhibit 99.4 REGISTRATION RIGHTS AGREEMENT Dated as of September 22, 1997 REGISTRATION RIGHTS AGREEMENT, dated as of September 22, 1997, by and between McKesson Corporation (the "Company"), and 399 Venture Partners, Inc. ("399 Venture"). 1....Registration Rights Agreement • September 24th, 1997 • Amerisource Distribution Corp • Wholesale-drugs, proprietaries & druggists' sundries • Delaware
Exhibit 99.3 VOTING/SUPPORT AGREEMENT ------------------------ AGREEMENT, dated as of September 22, 1997 (this "Agreement"), among McKesson Corporation, a Delaware corporation ("McKesson"), Patriot Acquisition Corp., a Delaware corporation ("Merger...Voting/ • September 24th, 1997 • Amerisource Distribution Corp • Wholesale-drugs, proprietaries & druggists' sundries • Delaware
