<PAGE>   1
                                                                   EXHIBIT 10.22

                           AMERICAN HOMEPATIENT, INC.

                                 PROMISSORY NOTE

$___________                                                  New York, New York
                                                                    May 25, 2001

                  FOR VALUE RECEIVED, AMERICAN HOMEPATIENT, INC., a Delaware
corporation ("BORROWER"), promises to pay to the order of ____________________
("PAYEE"), the principal amount of ________________________________
($________________) in the installments referred to below.

                  Borrower also promises to pay interest on the unpaid principal
amount hereof, from the date hereof until paid in full, at the rates and at the
times which shall be determined in accordance with the provisions of that
certain Fifth Amended and Restated Credit Agreement dated as of May 25, 2001 by
and among Borrower, the financial institutions listed therein as Lenders, and
Bankers Trust Company, as Agent (said Fifth Amended and Restated Credit
Agreement, as it may be amended, supplemented or otherwise modified from time to
time, being the "CREDIT AGREEMENT", the terms defined therein and not otherwise
defined herein being used herein as therein defined).

                  Borrower shall make principal payments on this Note on the
dates specified in the Credit Agreement and in the amounts determined in
accordance with the provisions thereof; provided that the last such installment
shall be in an amount sufficient to repay the entire unpaid principal balance of
this Note, together with all accrued and unpaid interest thereon.

                  This Note is one of Borrower's "Notes" in the aggregate
principal amount of $296,608,020.09 and is issued pursuant to and entitled to
the benefits of the Credit Agreement, to which reference is hereby made for a
more complete statement of the terms and conditions under which the Loan
evidenced hereby was made and is to be repaid.

                  All payments of principal and interest in respect of this Note
shall be made in lawful money of the United States of America in same day funds
at the office of the Agent located at One Bankers Trust Plaza, New York, New
York, or at such other place as shall be designated in writing for such purpose
in accordance with the terms of the Credit Agreement. Unless and until an
Assignment and Acceptance effecting the assignment or transfer of this Note
shall have been accepted by the Agent as provided in Section 11.05(b)(ii) of the
Credit Agreement, the Borrower and the Agent shall be entitled to treat Payee as
the owner and holder of this Note. Payee hereby agrees, by its acceptance
hereof, that before disposing of this Note or any part hereof it will make a
notation hereon of all principal payments previously made hereunder and of the
date to which interest hereon has been paid; provided, however, that the failure
to make a notation of any payment made on this Note shall not limit or otherwise
affect the obligations of Company hereunder with respect to payments of
principal of or interest on this Note.

                  Whenever any payment on this Note shall be stated to be due on
a day which is not a Business Day, such payment shall be made on the next
succeeding Business Day and such extension of time shall be included in the
computation of the payment of interest on this Note.


<PAGE>   2

                  This Note is subject to mandatory prepayment as provided in
subsection 4.02(b) of the Credit Agreement and to prepayment at the option of
Borrower as provided in subsection 4.02(a) of the Credit Agreement.

                  THIS NOTE AND THE RIGHTS AND OBLIGATIONS OF COMPANY AND PAYEE
HEREUNDER SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND ENFORCED IN
ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF NEW YORK (INCLUDING SECTION
5-1401 OF THE GENERAL OBLIGATIONS LAW OF THE STATE OF NEW YORK), WITHOUT REGARD
TO CONFLICTS OF LAWS PRINCIPLES.

                  Upon the occurrence of an Event of Default, the unpaid balance
of the principal amount of this Note, together with all accrued and unpaid
interest thereon, may become, or may be declared to be, due and payable in the
manner, upon the conditions and with the effect provided in the Credit
Agreement.

                  The terms of this Note are subject to amendment only in the
manner provided in the Credit Agreement.

                  This Note is subject to restrictions on transfer or assignment
as provided in subsection 11.05 of the Credit Agreement.

                  No reference herein to the Credit Agreement and no provision
of this Note or the Credit Agreement shall alter or impair the obligations of
Borrower, which are absolute and unconditional, to pay the principal of and
interest on this Note at the place, at the respective times, and in the currency
herein prescribed.

                  The Borrower promises to pay all costs and expenses, including
reasonable attorneys' fees, all as provided in subsection 11.01 of the Credit
Agreement, incurred in the collection and enforcement of this Note. The Borrower
and any endorsers of this Note hereby consent to renewals and extensions of time
at or after the maturity hereof, without notice, and hereby waive diligence,
presentment, protest, demand and notice of every kind and, to the full extent
permitted by law, the right to plead any statute of limitations as a defense to
any demand hereunder.

                  IN WITNESS WHEREOF, Borrower has caused this Note to be duly
executed and delivered by its officer thereunto duly authorized as of the date
and at the place first written above.


                                    AMERICAN HOMEPATIENT, INC.



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