<PAGE>

                                                                    EXHIBIT 10.1

                 FIRST AMENDMENT TO LOAN AND SECURITY AGREEMENT

      This First Amendment to Loan and Security Agreement ("Amendment") is made
as of the 22nd day of March, 2005, by and among Orion HealthCorp, Inc., Baytown
SurgiCare, Inc., Bellaire ASC L.P., Bellaire SurgiCare, Inc., Dennis Cain
Management, L.L.C., Dennis Cain Physician Solutions, Ltd., Integrated Physician
Solutions, Inc., IntegriMED, Inc., Medical Billing Services, Inc., San Jacinto
Surgery Center, Ltd., SurgiCare Memorial Village, L.P., TASC Anesthesia, LLC,
Town & Country SurgiCare, Inc., Tuscarawas Ambulatory Surgery Center, LLC, and
Tuscarawas Open MRI, LP. (collectively referred to as "Borrowers" and each
individually referred to as a "Borrower") Brantley Partners IV, L.P. ("Brantley
Partners") and Brantley Capital Corporation ("Brantley Capital" and collectively
with Brantley Partners, "Guarantors") and Healthcare Business Credit Corporation
("Lender").

                                   BACKGROUND

      A.    Borrowers and Lender are parties to a certain Loan and Security
Agreement dated as of December 15, 2004 (as modified and amended from time to
time "Loan Agreement") pursuant to which Borrowers established certain financing
arrangements with Lender. The Loan Agreement and all instruments, documents and
agreements executed in connection therewith, or related thereto are referred to
herein collectively as the "Existing Loan Documents." All capitalized terms not
otherwise defined herein shall have the meaning ascribed thereto in the Loan
Agreement.

      B.    The following Events of Default have occurred under the Loan
Agreement: (i) failure to comply with Section 6.7(a)(ii) for the fiscal quarter
ending December 31, 2004 which requires Borrowers to deliver to Lender
Borrowers' internally prepared quarterly financial statement within 45 days of
the end of each fiscal quarter and (ii) failure to comply with Section 6.12 of
the Loan Agreement which requires Borrowers to provide thirty days prior written
notice to Lender of any changes to the location of any place of business
(collectively, "Existing Defaults").

      C.    Borrowers have requested and Lender has agreed to waive the Existing
Defaults and amend the terms and conditions of the Existing Loan Documents
(including by instituting the Special Accommodation and reducing the Revolving
Loan Commitment) pursuant to the terms and conditions of this Amendment.

      NOW, THEREFORE, with the foregoing Background incorporated by reference
and made a part hereof and intending to be legally bound, the parties agree as
follows:

      1.    Waiver of Existing Event of Default. Borrowers acknowledge and agree
that as of this date, the Existing Defaults have occurred and remain outstanding
under the Existing Loan Documents. Upon the effectiveness of this Amendment,
Lender hereby waives the Existing Defaults. Such waiver shall in no way
constitute a waiver of any other Event of Default which may have occurred but
which is not specifically referenced as an "Existing Default," nor shall it
obligate Lender to provide any further waiver of any other Event of Default
(whether similar or dissimilar, including any further Events of Default
resulting from a failure to comply with Section 6.7(a)(ii) or 6.12 of the Loan
Agreement).

      2.    Amendments. Upon effectiveness of this Amendment:

<PAGE>

            (a)   Section 1.1 of the Loan Agreement is hereby amended by
inserting the following definition:

                  "ORIGINAL COMMITMENT" means an amount equal to Four Million
                  Dollars ($4,000,000).

                  "SOLOMON LITIGATION RESERVE" means an amount equal to $544,000
                  or such lesser or greater amount as may be determined from
                  time to time by Lender is its sole discretion.

                  "SPECIAL ACCOMMODATION" means the following amounts for the
                  corresponding periods:

<TABLE>
<CAPTION>
             Period                     Amount
             ------                     ------
<S>                                 <C>
For the period from March 4, 2005
through March 10, 2005              $700,000 minus the
                                    aggregate amount of
                                    all Accommodation
                                    Reductions

For the period from March 11, 2005
through March 17, 2005              $650,000 minus the
                                    aggregate amount of
                                    all Accommodation
                                    Reductions

For the period from March 18, 2005
through March 24, 2005              $575,000 minus the
                                    aggregate amount of
                                    all Accommodation
                                    Reductions

For the period from March 25, 2005
through March 31, 2005              $500,000 minus the
                                    aggregate amount of
                                    all Accommodation
                                    Reductions

For the period from April 1, 2005
through April 7, 2005               $400,000 minus the
                                    aggregate amount of
                                    all Accommodation
                                    Reductions

For the period from April 8, 2005
through April 14, 2005              $300,000 minus the
                                    aggregate amount of
</TABLE>

                                       2
<PAGE>

<TABLE>
<S>                                 <C>
                                    all Accommodation
                                    Reductions

For the period from April 15, 2005
through April 21, 2005              $200,000 minus the
                                    aggregate amount of
                                    all Accommodation
                                    Reductions

For the period from April 22, 2005
 through April 28, 2005             $100,000 minus the
                                    aggregate amount of
                                    all Accommodation
                                    Reductions

For the period from April 29, 2005
 and thereafter                     $0
</TABLE>

                  Notwithstanding the foregoing, the Special Accommodation shall
                  be reduced on a dollar for dollar basis contemporaneously with
                  each reduction in the Solomon Litigation Reserve until such
                  time as the Special Accommodation has been reduced to $0 (each
                  such reduction, an "ACCOMMODATION REDUCTION").

            (b)   The following definitions set forth in Section 1.1 of the Loan
Agreement are each hereby deleted and replaced with the following:

                  "BORROWING BASE" means, at any date, an amount equal to the
                  lesser of (a) the Revolving Loan Commitment, or (b) the sum of
                  (i) the product of (X) the applicable Advance Rate then in
                  effect, times (Y) the Estimated Net Value of all Eligible
                  Accounts as of such date, plus (ii) the Special Accommodation.

                  "REVOLVING LOAN COMMITMENT" means an amount equal to Two
                  Million Seven Hundred and Fifty Thousand Dollars ($2,750,000).

            (c)   Sections 2.3 (c) and (d) of the Loan Agreement are hereby
deleted and replaced with the following:

                  (c)   Should the Credit Facility be terminated for any reason
                  prior Obligations then outstanding and termination of Lender's
                  commitment hereunder, Borrowers shall unconditionally be
                  obligated to pay at the time of such termination, a fee
                  ("TERMINATION FEE") in an amount equal to the following
                  percentage of the Original Commitment:

                                       3
<PAGE>

                  three percent (3.0%), if such early termination occurs on or
                  prior to the first anniversary date of this Agreement; two
                  percent (2.0%) if such early termination occurs after the
                  first anniversary date of this Agreement but on or before the
                  second anniversary of this Agreement; and one percent (1.0%)
                  if such early termination occurs after the second anniversary
                  of the date of this Agreement but prior to the last day of the
                  Initial Term. Borrowers acknowledge that the Termination Fee
                  is an estimate of Lender's damages in the event of early
                  termination and is not a penalty. In the event of termination
                  of the Credit Facility, all of the Obligations shall be
                  immediately due and payable upon the termination date stated
                  in any notice of termination. All undertakings, agreements,
                  covenants, warranties and representations of Borrowers
                  contained in the Loan Documents shall survive any such
                  termination, and Lender shall retain its security interests in
                  the Collateral and all of its rights and remedies under the
                  Loan Documents notwithstanding such termination until
                  Borrowers have paid the Obligations to Lender, in full, in
                  immediately available funds, together with the applicable
                  Termination Fee, if any. Notwithstanding the payment in full
                  of the Obligations, Lender shall not be required to terminate
                  its security interests in the Collateral unless either (1) the
                  Obligations have been indefeasibly paid and satisfied in full
                  pursuant to the Guaranty Agreement, or (2) if the Obligations
                  have been satisfied by means other than Lender's rights under
                  the Guaranty Agreement, with respect to any loss or damage
                  Lender may incur as a result of dishonored checks or other
                  items of payment received by Lender from Borrowers or any
                  Obligor and applied to the Obligations, Lender shall, at its
                  option, (i) have received a written agreement executed by
                  Borrowers and by any Person whose loans or other advances to
                  Borrowers are used in whole or in part to satisfy the
                  Obligations, indemnifying Lender from any such loss or damage;
                  or (ii) have retained such monetary reserves and security
                  interests on the Collateral for such period of time as Lender,
                  in its reasonable discretion, may deem necessary to protect
                  Lender from any such loss or damage.

                  (d)   Borrowers shall unconditionally pay to Lender a fee
                  ("UNUSED LINE FEE") equal to three quarters of one percent
                  (0.75%) per annum of the unused portion of the Credit
                  Facility. The unused portion of the Credit Facility shall be
                  the difference between the Revolving Loan Commitment and the
                  average daily outstanding balance of the Loans during each
                  month (or portion thereof), which fees shall be calculated and
                  payable monthly, in arrears, and shall be due

                                       4
<PAGE>

                  and payable on the first Designated Funding Date of each
                  calendar month.

            (d)   The Guaranty Agreements referenced and defined in the Loan
Agreement shall mean, collectively, that certain Amended and Restated Guaranty
Agreement dated of even date herewith executed by Brantley Partners in favor of
Lender and that certain Amended and Restated Guaranty Agreement dated of even
date herewith executed by Brantley Capital in favor of Lender.

            (e)   Notwithstanding anything to the contrary contained in the Loan
Agreement, on or before March 31, 2005, Borrower shall deliver to Lender
Borrowers' internally prepared quarterly financial statements and other reports
as required by Section 6.7(a)(ii) of the Loan Agreement for the fiscal quarter
ended December 31, 2004.

            (f)   Notwithstanding anything to the contrary contain in that
certain post-closing letter dated December 15, 2004 among Borrowers and Lender,
on or before March 31, 2005, Borrowers shall have caused Pediatric Specialists
of the Northwest, M.D. S.C. to execute a letter in substantially the form
attached as Exhibit A to the post-closing letter.

      3.    Fees. Prior to the effectiveness of this Amendment, Borrowers agree
to pay to Lender a non-refundable amendment fee ("Amendment Fee") in an amount
equal to Ten Thousand Dollars ($10,000).

      4.    Representations and Warranties. Borrowers represent and warrant to
Lender that:

            (a)   All warranties and representations made to Lender under the
Loan Agreement and the Existing Loan Documents are true and correct as to the
date hereof.

            (b)   The execution and delivery by Borrowers of this Agreement and
the performance by it of the transactions herein contemplated (i) are and will
be within its powers, (ii) have been authorized by all necessary organizational
action, and (iii) are not and will not be in contravention of any order of any
court or other agency of government, of law or any other indenture, agreement or
undertaking to which such Borrower is a party or by which the property of such
Borrower is bound, or be in conflict with, result in a breach of, or constitute
(with due notice and/or lapse of time) a default under any such indenture,
agreement or undertaking or result in the imposition of any lien, charge or
encumbrance of any nature on any of the properties of any Borrower.

            (c)   This Amendment and any assignment, instrument, document, or
agreement executed and delivered in connection herewith, will be valid, binding,
and enforceable in accordance with its respective terms.

            (d)   No Event of Default or Unmatured Event of Default, other than
the Existing Defaults, has occurred and is continuing under the Loan Agreement
or any of the other Existing Loan Documents.

      5.    Effectiveness Conditions. This Amendment shall be effective upon
completion of the following conditions precedent (all documents to be in form
and substance satisfactory to Lender and Lender's counsel):

                                       5
<PAGE>

            (a)   Execution by Borrowers and delivery to Lender of this
Amendment and the Amended and Restated Revolving Credit Note;

            (b)   Execution by Borrowers and John Ivan Sutter, M.D. P.A. and
delivery to Lender of that certain Governmental Depository Agreement among
Lockbox Bank, Lender, John Ivan Sutter, M.D. P.A. and Integrated Physician
Solutions, Inc.

            (c)   Execution by Brantley Partners and Brantley Capital and
delivery to Lender of the respective Amended and Restated Guaranty Agreements;

            (d)   Delivery to Lender of a fully executed Landlord Waiver for
10700 Richmond Avenue, Houston, Texas;

            (e)   Delivery to Lender by Brantley Partners of financial reports
and certificates as required by Paragraph 18 and 19 of the Amended and Restated
Guaranty Agreement executed by Brantley Partners in favor of Lender;

            (f)   Payment of all fees, costs and Expenses related to the
documentation and negotiation of this Amendment and the transactions
contemplated hereby (including, without limitation, the Amendment Fee and
attorneys' fees); and

            (g)   Execution and/or delivery of all agreements, instruments and
documents requested by Lender to effectuate and implement the terms hereof and
the Existing Loan Documents.

      6.    Confirmation of Indebtedness. Borrowers hereby acknowledge and
confirm that as of the close of business on March 11, 2005, Borrowers are
indebted to Lender, without defense, setoff, claim or counterclaim, under the
Loan Documents, in the aggregate principal amount of $2,445,527.86, plus all
fees, costs and expenses (including attorneys' fees) incurred to date in
connection with the Loan Documents.

      7.    Ratification of Existing Loan Documents. Except as expressly set
forth herein, all of the terms and conditions of the Loan Agreement and Existing
Loan Documents are hereby ratified and confirmed and continue unchanged and in
full force and effect. All references to the Loan Agreement shall mean the Loan
Agreement as modified by this Amendment.

      8.    Security Interest. Borrowers hereby confirm and agree that all
security interests and liens granted to Lender continue to be perfected, first
priority liens and remain in full force and effect and shall continue to secure
the Obligations. All Collateral remains free and clear of any liens other than
liens in favor of Lender. Nothing herein contained is intended to in any way
impair or limit the validity, priority, and extent of Lender's existing security
interest in and liens upon the Collateral.

      9.    Acknowledgment of Guarantors. By execution of this Amendment,
Brantley Partners, pursuant to the terms of the Amended and Restated Guaranty
Agreement of even date herewith, and Brantley Capital, pursuant to the terms to
the Amended and Restated Guaranty Agreement of even date herewith, hereby accept
and acknowledge the terms and conditions of this

                                       6
<PAGE>

Amendment. Each Guarantor hereby covenants and agrees that its respective
Guaranty Agreement is in full force and effect and continues to cover the
existing and future Obligations of Borrowers to Lender.

      10.   Release. As further consideration for Lender's agreement to grant
the accommodations and waiver set forth herein, Borrowers and Guarantors hereby
waive and release and forever discharge Lender and its officers, directors,
attorneys, agents and employees from any liability, damage, claim, loss or
expense of any kind that Borrowers, Guarantors, or any of them, may now or
hereafter have against Lender arising out of or relating to the Obligations,
this Agreement or the Existing Loan Documents.

      11.   Governing Law. This Amendment, and all matters arising out of or
relating to this Amendment, shall be governed by, construed, and enforced in
accordance with the substantive laws of the State of New Jersey.

      12.   Counterparts. This Amendment may be executed in any number of
counterparts, each of which when so executed shall be deemed to be an original,
and such counterparts together shall constitute one and the same respective
agreement. Signature by facsimile and/or PDF shall bind the parties hereto.

                            [SIGNATURE PAGE FOLLOWS]

                                        7
<PAGE>

      IN WITNESS WHEREOF, the parties have executed this Amendment the day and
year first above written.

BORROWERS:
                           ORION HEALTHCORP, INC.

                           By: /s/ Terrence L. Bauer
                               --------------------------------
                           Name: Terrence L. Bauer
                           Title: Chief Executive Officer

                           BAYTOWN SURGICARE, INC.

                           By: /s/ Keith LeBlanc
                               --------------------------------
                           Name: Keith LeBlanc
                           Title: President

                           BELLAIRE ASC L.P.
                           By: Bellaire SurgiCare, Inc., its general partner

                           By: /s/ Keith LeBlanc
                               --------------------------------
                           Name: Keith LeBlanc
                           Title: President

                           BELLAIRE SURGICARE, INC.

                           By: /s/ Keith LeBlanc
                               --------------------------------
                           Name: Keith LeBlanc
                           Title: President
                           DENNIS CAIN MANAGEMENT, L.L.C.

                           By: /s/  Keith LeBlanc
                               ---------------------------------
                           Name: Keith LeBlanc
                           Title: Manager

                           DENNIS CAIN PHYSICIAN SOLUTIONS, LTD.
                           By: Dennis Cain Management, L.L.C.

                           By: /s/ Keith LeBlanc
                               ----------------------------------
                           Name: Keith LeBlanc
                           Title: Manager

                     [SIGNATURE CONTINUE ON FOLLOWING PAGE]

                                      S-1
<PAGE>

                              INTEGRATED PHYSICIAN SOLUTIONS, INC.

                              By: /s/ Terrence L. Bauer
                                  ---------------------------------
                              Name: Terrence L. Bauer
                              Title: President and Chief Executive Officer

                              INTEGRIMED, INC.

                              By: /s/ Terrence L. Bauer
                                  --------------------------------
                              Name: Terrence L. Bauer
                              Title: President

                              MEDICAL BILLING SERVICES, INC.

                              By: /s/ Stephen H. Murdock
                                  --------------------------------
                              Name: Stephen H. Murdock
                              Title: Chief Financial Officer

                              SAN JACINTO SURGERY CENTER, LTD.
                              By: Baytown SurgiCare, Inc., its general partner

                              By: /s/ Keith LeBlanc
                                  --------------------------------
                              Name: Keith LeBlanc
                              Title: President

                              SURGICARE MEMORIAL VILLAGE, L.P.
                              By: Town & Country SurgiCare, Inc., its general
                                  partner

                              By: /s/ Keith LeBlanc
                                  --------------------------------
                              Name: Keith LeBlanc
                              Title: President

                              TASC ANESTHESIA, LLC
                              By: Tuscarawas Ambulatory Surgery Center, LLC, its
                                  manager

                              By: /s/ Keith LeBlanc
                                  --------------------------------
                              Name: Keith LeBlanc
                              Title: President

                     [SIGNATURE CONTINUE ON FOLLOWING PAGE]

                                      S-2
<PAGE>

                           TOWN & COUNTRY SURGICARE, INC.

                           By: /s/ Keith LeBlanc
                               --------------------------------
                           Name: Keith LeBlanc
                           Title: President

                           TUSCARAWAS AMBULATORY SURGERY CENTER, LLC

                           By: /s/ Keith LeBlanc
                               --------------------------------
                           Name: Keith LeBlanc
                           Title: Manager

                           TUSCARAWAS OPEN MRI, LP
                           By: Orion HealthCorp, Inc., its general
                               partner

                           By: /s/ Keith LeBlanc
                               --------------------------------
                           Name: Keith LeBlanc
                           Title: President

GUARANTORS:                BRANTLEY PARTNERS IV, LP
                           By: Brantley Venture Management IV, L.P., its general
                               partner

                           By: /s/ Paul H. Cascio
                               --------------------------------
                           Name: Paul H. Cascio
                           Title: Authorized Signatory

                           BRANTLEY CAPITAL CORPORATION

                           By: /s/ Paul H. Cascio
                               --------------------------------
                           Name: Paul H. Cascio
                           Title: Vice President

LENDER:                    HEALTHCARE BUSINESS CREDIT CORPORATION

                           By: /s/ Michael D. Gervais
                               ---------------------------------
                           Name: Michael D. Gervais
                           Title: VP-Portfolio Management

                                      S-3