<PAGE>   1
                                                                    EXHIBIT 10.5

                                 PROMISSORY NOTE

June 6, 2000                                                         $900,000.00

                  FOR VALUE RECEIVED, the undersigned (hereinafter referred to
as "MAKER") promises to pay to the order of HORIZON MEDICAL PRODUCTS, INC., a
Georgia corporation (hereinafter referred to as "PAYEE"), at Payee's office at
Seven Northside Parkway Square, 4200 Northside Parkway, Atlanta, Georgia 30327,
or at such other place as the holder hereof may designate, the principal sum of
Nine Hundred Thousand and No/100 Dollars ($900,000.00), together with interest
on so much of the principal balance of this Note as may be outstanding and
unpaid from time to time, calculated on the basis of a 360 day year and actual
days elapsed, at the Applicable Interest Rate, as defined herein.

                  Maker acknowledges that Payee has advanced $806,245.83 of the
principal amount hereof directly to Prudential Securities Incorporated
("PRUDENTIAL"), in full payment of a certain margin loan made by Prudential to
Maker, and secured by certain securities pledged by Maker to Prudential, which
securities are being pledged by Maker as security for this Note.

                  Principal and interest shall be due and payable in full on
August 30, 2000. Any overdue payment of principal or interest on this Note shall
bear interest at the Applicable Interest Rate plus two percentage points (2.0%)
until paid, but only to the extent that payment of such interest on overdue
principal or interest is enforceable under applicable law.

                  As used herein, the term "APPLICABLE INTEREST RATE" shall mean
either (i) the Index Rate, plus four and one-half percentage points (4.50%) or
(ii) Adjusted LIBOR plus four and one-half percentage points (4.50%), as elected
by Payee upon execution hereof and on the first business day of each month
thereafter (the "INTEREST DETERMINATION DATE"). "ADJUSTED LIBOR" shall mean a
rate per annum (rounded upward, if necessary to the next higher 1/16 of 1%)
equal to the rate obtained by dividing (a) LIBOR (similarly rounded) by (b) a
percentage equal to 1 minus the Reserve Requirement in effect from time to time.
"INDEX RATE" shall mean, for any day in any calendar month, the rate of interest
equivalent to the money market yield for the Interest Determination Date falling
in such month on the one month commercial paper rate for dealer-placed
commercial paper of issuers whose corporate bonds are rated "AA" or its
equivalent by a nationally recognized rating agency, as such rate is made
available on a discount basis or otherwise by the Federal Reserve Bank of New
York and published weekly by the Board of Governors of the Federal Reserve
System in its H.15 report, or any successor publication published by the Board
of Governors of the Federal Reserve System or, if such rate for such date is not
yet published in such statistical release, the rate for that date will be the
rate set forth in the weekly statistical release designated as such, or any
successor publication, published by the Board of Governors of the Federal
Reserve System. "LIBOR" shall mean, with respect to any Interest Determination
Date, (i) the London Interbank Offered Rate for deposits in U.S. dollars for a
period comparable to the period from and including such Interest Determination
Date to and including the next Interest Determination Date which is published in
The Wall Street Journal (Eastern Edition) under the caption "Money Rates -
London Interbank Offered Rates (LIBOR)"


<PAGE>   2

on such date of determination; or (ii) if The Wall Street Journal does not
publish such rate, the offered rate for deposits in U.S. dollars for a period of
time comparable to the period from and including such Interest Determination
Date to and including the next succeeding Interest Determination Date which
appears on the Dow Jones Markets Page 3750 as of 10:00 a.m., New York time, on
such Interest Determination Date, provided that if at least two rates appear on
the Dow Jones Markets Page 3750, the "London Interbank Offered Rate" applicable
to such period shall be the arithmetic mean of such rates; or (iii) if The Wall
Street Journal does not publish such rate and no such rate appears on the Dow
Jones Markets Page 3750 at such time, the rate per annum at which deposits in
U.S. dollars are offered by the principal London office of The Chase Manhattan
Bank, N.A. to leading banks in the London interbank market at approximately
11:00 a.m., London time, on such Interest Determination Date in an amount
approximately equal to the principal amount of the Loans for a period of time
comparable to the period from and including such Interest Determination Date to
and including the next succeeding Interest Determination Date, in each case as
determined by Bank of America, N.A. (or an affiliate thereof) whose
determination shall be conclusive absent manifest error. "RESERVE REQUIREMENT"
shall mean at any time the then current maximum rate for which reserves
(including any marginal, supplemental or emergency reserve) are required to be
maintained under Regulation D by member banks of the Federal Reserve System in
New York City with deposits comparable in amount to those of Bank of America,
N.A. against "Eurocurrency liabilities", as that term is used in Regulation D.
Adjusted LIBOR shall be adjusted automatically on and as of the effective date
of any change in the Reserve Requirement. It is the intent of Maker and Payee
that the interest payable by Maker under this Note shall be equal to the
interest payable by Payee on the Bridge Loan advanced to Payee pursuant to the
Amended and Restated Credit Agreement, dated as of May 26, 1998, by and among
Horizon Medical Products, Inc., the lenders referred to therein, and Banc of
America Commercial Finance Corporation (formerly NationsCredit Commercial
Corporation), as Agent for such lenders, as amended from time to time (the
"HORIZON CREDIT AGREEMENT").

                  Maker may prepay this Note in whole or in part at any time
without penalty or premium.

                  The occurrence of any one or more of the following events will
constitute a default by Maker hereunder (hereinafter referred to as an "EVENT OF
DEFAULT"): (i) Maker fails to pay when due any amount payable under this Note or
otherwise fails to perform or breaches a covenant in this Note; (ii) any
statement, representation, or warranty made by Maker or on Maker's behalf in
connection with this Note proves to have been untrue, incorrect, misleading or
incomplete in any material respect as of the date made; (iii) the occurrence of
a default, event of default or Event of Default under any other agreement to
which Payee and Maker are parties or under any other instrument executed by
Maker in favor of Payee, including without limitation any loan and security
agreement, loan agreement, security agreement, pledge agreement, security deed,
note or guaranty; (iv) Maker becomes insolvent as defined in the Georgia Uniform
Commercial Code or makes an assignment for the benefit of creditors, or an
action is brought by Maker seeking Maker's dissolution or liquidation of his
assets or seeking the appointment of a trustee, interim trustee, receiver or
other custodian for any of his property, or Maker commences a voluntary case
under the Federal Bankruptcy Code, or a reorganization or arrangement


                                       2
<PAGE>   3

proceeding is instituted by Maker for the settlement, readjustment, composition
or extension of any of his debts upon any terms, or an action or petition is
otherwise brought by Maker seeking similar relief or alleging that he is
insolvent or unable to pay his debts as they mature; (v) an action is brought
against Maker seeking Maker's dissolution or liquidation of any of his assets or
seeking the appointment of a trustee, interim trustee, receiver or other
custodian for any of his property, and such action is consented to or acquiesced
in by Maker or is not dismissed within thirty (30) days of the date upon which
it was instituted, or a proceeding under the Federal Bankruptcy Code is
instituted against Maker and an order for relief is entered in such proceeding
or such proceeding is consented to or acquiesced in by Maker or is not dismissed
within thirty (30) days of the date upon which it was instituted, or a
reorganization or arrangement proceeding is instituted against Maker for the
settlement, readjustment, composition or extension of any of his debts upon any
terms and such proceeding is consented to or acquiesced in by Maker or is not
dismissed within thirty (30) days of the date upon which it was instituted, or
an action or petition is otherwise brought against Maker seeking similar relief
or alleging that he is insolvent, unable to pay his debts as they mature or
generally not paying his debts as they become due and such action or petition is
consented to or acquiesced in by Maker or is not dismissed within thirty (30)
days of the date upon which it was brought; (vi) the death of Maker; (vii) Maker
repudiates or attempts to repudiate his obligations or liabilities under this
Note or under any other agreement to which Payee and Maker are parties or any
other instrument executed by Maker in favor of Payee, including without
limitation any loan and security agreement, loan agreement, security agreement,
pledge agreement, security deed, note or guaranty; (viii) any guarantor of this
Note terminates or attempts to terminate such guaranty; (ix) any material
adverse change occurs in Maker's financial condition or means or ability to pay
this Note; (x) the occurrence of any "Event of Default" under (and as defined
in) the Horizon Credit Agreement; or (xi) the average daily Closing Price (as
determined over a period of three consecutive trading days) of the common stock
of Horizon Medical Products, Inc. shall at any time be less than or equal to
$1.25 per share (for purposes of the foregoing, "CLOSING PRICE" on any day shall
mean (a) if the common stock is listed or admitted for trading on a national
securities exchange, the reported last sales price regular way or, if no such
reported sale occurs on such day, the average of the closing bid and asked
prices regular way on such day, in each case on the principal national
securities exchange on which the common stock is listed or admitted to trading,
or (b) if the common stock is not listed or admitted to trading on any national
securities exchange, the average of the closing bid and asked prices in the
over-the-counter market on such day as reported by NASDAQ or any comparable
system or, if not so reported, as reported by any New York Stock Exchange member
firm selected by Payee for such purpose).

                  Upon the occurrence of an Event of Default, Payee, at its
option, without demand or notice of any kind, may declare this Note immediately
due and payable, whereupon all outstanding principal and accrued interest shall
become immediately due and payable; provided, however, that Payee shall give
Maker written notice of such Event of Default at least ten (10) days prior to
exercising its rights and remedies to collect the indebtedness evidenced by this
Note.

                  In case this Note is collected by or through an
attorney-at-law, all costs of collection, including reasonable attorney's fees,
shall be paid by Maker.


                                       3
<PAGE>   4

                  Time is of the essence.

                  Demand, presentment, notice, notice of demand, notice for
payment, protest and notice of dishonor are hereby waived by each and every
maker, guarantor, surety and other Person or entity primarily or secondarily
liable on this Note.

                  Maker agrees that, in addition to and without limitation of
any right of setoff or counterclaim which Payee may otherwise have against
Maker, upon the occurrence of any Event of Default hereunder, Payee shall be
entitled, at its option, to setoff amounts owed by it to Maker or amounts held
by it on or for the account of Maker against any principal, interest or other
amounts owing from Maker to Payee hereunder.

                  Payee shall not be deemed to waive any of its rights unless
such waiver be in writing and signed by Payee. No delay or omission by Payee in
exercising any of its rights shall operate as a waiver of such rights and a
waiver in writing on one occasion shall not be construed as a consent to or a
waiver of any right or remedy on any future occasion. This Note may not be
amended or modified in any manner except by written instrument executed by Payee
and Maker.

                  In no event shall the amount of interest due and payable under
this Note exceed the maximum rate of interest allowed by applicable law
(including, without limitation, O.C.G.A ss. 7-4-18) and, in the event any such
payment is made by Maker or received by Payee, such excess sum shall be credited
as a payment of principal (or if no principal shall remain outstanding, shall be
refunded to Maker). It is the express intent hereof that Maker not pay and Payee
not receive, directly or indirectly or in any manner, interest in excess of that
which may be lawfully paid under applicable law.

                  This Note shall be governed by and construed and enforced in
accordance with the laws of the State of Georgia. Wherever possible, each
provision of this Note shall be interpreted in such manner as to be effective
and valid under applicable law, but if any provision of this Note shall be
prohibited by or invalid under applicable law, such provision shall be
ineffective only to the extent of such prohibition or invalidity, without
invalidating the remainder of such provision or the remaining provisions of this
Note.

                  This Note is secured by those certain Pledge Agreements, dated
of even date herewith, executed by each Maker in favor of Payee.

                  Words importing the singular number hereunder shall include
the plural number and vice versa, and any pronoun used herein shall be deemed to
cover all genders. Without limiting the generality of the foregoing, should more
than one person execute this Note as maker, the words "Maker", "he" and "his" as
used herein shall include all such persons collectively and each such person
individually, and each maker shall be jointly and severally liable hereunder.
"Person" as used herein means any individual, corporation, partnership, limited
liability company, joint venture, association, joint stock company, trust,
unincorporated association or government or any agency or political subdivision
thereof.


                                       4
<PAGE>   5

                  The word "Payee" as used herein shall include transferees,
successors and assigns of Payee, and all rights of Payee hereunder shall inure
to the benefit of its transferees, successors and assigns. All obligations of
Maker shall bind his heirs, legal representatives, successors and assigns.

                  MAKER HEREBY WAIVES, TO THE MAXIMUM EXTENT PERMITTED BY
APPLICABLE LAW, ANY RIGHT MAKER MAY HAVE UNDER ANY APPLICABLE LAW TO A TRIAL BY
JURY WITH RESPECT TO ANY SUIT OR LEGAL ACTION WHICH MAY BE COMMENCED BY OR
AGAINST PAYEE CONCERNING THE INTERPRETATION, CONSTRUCTION, VALIDITY, ENFORCEMENT
OR PERFORMANCE OF THIS NOTE. IN THE EVENT ANY SUCH SUIT OR LEGAL PROCEEDING IS
COMMENCED BY OR AGAINST PAYEE, MAKER HEREBY EXPRESSLY AGREES, CONSENTS AND
SUBMITS TO THE NONEXCLUSIVE JURISDICTION OF THE UNITED STATES DISTRICT COURT FOR
THE NORTHERN DISTRICT OF GEORGIA AND OF ANY GEORGIA STATE COURT SITTING IN
ATLANTA WITH RESPECT TO SUCH SUIT OR LEGAL ACTION, AND MAKER ALSO IRREVOCABLY
WAIVES, TO THE FULLEST EXTENT PERMITTED BY LAW, ANY OBJECTION WHICH IT MAY NOW
OR HEREAFTER HAVE TO THE LAYING OF THE VENUE OF ANY SUCH PROCEEDING BROUGHT IN
SUCH A COURT AND ANY CLAIM THAT ANY SUCH PROCEEDING BROUGHT IN SUCH A COURT HAS
BEEN BROUGHT IN AN INCONVENIENT FORUM. THE JURISDICTION AND VENUE OF THE COURTS
SUBMITTED TO AND AGREED UPON IN THIS PARAGRAPH ARE NOT EXCLUSIVE BUT ARE
CUMULATIVE AND IN ADDITION TO THE JURISDICTION OF ANY OTHER COURT UNDER ANY
APPLICABLE LAWS OR IN EQUITY. MAKER HEREBY AGREES THAT MAKER SHALL NOT INSTITUTE
ANY SUIT OR LEGAL ACTION AGAINST PAYEE CONCERNING THE INTERPRETATION,
CONSTRUCTION, VALIDITY, ENFORCEMENT OR PERFORMANCE OF THIS NOTE EXCEPT IN A
STATE OR FEDERAL COURT SITTING IN ATLANTA, GEORGIA AND HEREBY EXPRESSLY CONSENTS
TO THE REMOVAL OF ANY SUCH SUIT OR LEGAL ACTION FILED BY MAKER IN ANY OTHER
VENUE TO ANY STATE OR FEDERAL COURT SITTING IN ATLANTA, GEORGIA.


                                       5
<PAGE>   6

                  SIGNED, SEALED AND DELIVERED by the undersigned as of the day
and year first above set forth.

                                            HUNT FAMILY INVESTMENTS, L.L.L.P.
Witness:
        -----------------------

                                            By:                           (SEAL)
                                               ---------------------------
                                            Name:
                                                 -------------------------------
                                            Title:
                                                  ------------------------------


                                            ------------------------------(SEAL)
Witness:                                    MARSHALL B. HUNT, INDIVIDUALLY
        -----------------------


                                            Address:
                                                    ------------------------
                                                    ------------------------
                                                    ------------------------


<PAGE>   7

                                   ENDORSEMENT

         Pay to the order of BANC OF AMERICA COMMERCIAL FINANCE CORPORATION
(formerly NationsCredit Commercial Corporation), as Agent (the "AGENT") for
itself and any other lenders signatories the Amended and Restated Credit
Agreement, dated as of May 26, 1998, between the undersigned, such lenders and
the Agent, with recourse.

                                    HORIZON MEDICAL PRODUCTS, INC.


                                    By:
                                       ----------------------------------
                                    Name:
                                         --------------------------------
                                    Title:
                                          -------------------------------