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NEITHER THIS SENIOR NOTE (THIS NOTE) NOR THE SHARES OF STOCK THAT MAY BE ISSUABLE UPON REPAYMENT
OF ANY PORTION OF THIS NOTE, IF APPLICABLE, HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,
AS AMENDED. THE HOLDER MAY NOT TRANSFER THIS NOTE OR THE SHARES OF STOCK THAT MAY BE ISSUABLE UPON
REPAYMENT OF ANY PORTION OF THIS NOTE UNLESS (A) THERE IS AN EFFECTIVE REGISTRATION COVERING THIS
NOTE OR THE SHARES OF STOCK THAT MAY BE ISSUABLE UPON REPAYMENT OF ANY PORTION OF THIS NOTE UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, AND APPLICABLE STATE SECURITIES LAWS OR (B) IF REQUESTED BY
AVANIR PHARMACEUTICALS, IT FIRST RECEIVES A LETTER FROM AN ATTORNEY REASONABLY ACCEPTABLE TO IT
STATING THAT IN THE OPINION OF THE ATTORNEY THE PROPOSED TRANSFER IS EXEMPT FROM REGISTRATION UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, AND UNDER ALL APPLICABLE STATE SECURITIES LAWS.
 SENIOR NOTE
 $4,000,000.00
    
    May 24, 2006 (the Execution Date)
Costa Mesa, California
 Payor Holder Note
 Purchase Agreement Schedule A Buyer Note 1 Buyer Note 2 Additional Notes
  Average Price




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Business Day
 Closing Price
 Events of Default
 Financing Prepayment Date provided, however
 Financing Transaction
 Initial Threshold Price
  Interest Determination Date
  Interest Payment Date 
  Interest Period 
 Interest Rate
 2




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LIBOR
  London Business Day 
 Market Disruption Event
 Maturity Date
 Payor Common Stock
 Pledge Expiration Date
 Prepayment Election Date
 Prepayment Election Notice
 Repayment Amount
 Repayment Stock
 3




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Registration Rights Agreement
 Securities Act
 Stock Equivalents
 Threshold Price
 Trading Day
 Trigger Event
 1. Interest; Repayment Prior to Maturity.
 Interest
  Interest Determination Date Interest Rate
 4




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Cash Prepayment at Payors Option
 Stock Prepayment at Payors Option
     Delivery of Prepayment Stock
 5




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Registration
 Financing Prepayments
   2. Repayment at Maturity.
 Repayment
 Delivery of Note
 6




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3. Threshold Price Adjustments.
 Stock Splits, Dividends, Etc Stock
Equivalents
 Reverse Stock Split, Combination
 Successive Adjustments
 Minimal Adjustments
 Adjustment Notice
 4. Transfer, Legend and Stop Transfer Orders.
  7




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Exhibit A
 5. Security Interest.
   8




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6. Rights of Holder.
  7. Representation and Warranties.
 Holder
 Payor
   8. Covenants of Payor
 9. Events of Default.
 Events of Default
   9




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10




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10. Governing Law.
  11. Waiver.
  12. Loss, Theft, Destruction or Mutilation.
  13. Assignment.
 provided,
however provided, further
 14. Amendments and Waivers.
  15. Notices
  11




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If to Payor:
    
    Avanir Pharmaceuticals11388 Sorrento Valley Rd.San Diego, CA 92121Attention: Michael PuntorieroTelephone: (858) 622-5200Fax: (858) 658-7447With a copy to:
    
    Latham & Watkins LLP650 Town Center Drive, 20th FloorCosta Mesa, CA 92626Attention: Cary K. Hyden and Jonn R. BeesonTelephone: (714) 540-1235Fax: (714) 755-8290If to Cutler:
    
    Neal R. Cutler[Address}With a copy to:
    
    Milbank, Tweed, Hadley & McCloy LLP601 South Figueroa Street, 30th FloorLos Angeles, California 90017Attn: Brett GoldblattTelephone: (213) 892-4000Fax: (213) 629-5063If to any other
Person who is then
the Holder:
    
    To the address of such Holder as it appears in the certificate
provided to Payor in accordance with Section 5.2
   12




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AVANIR
    
    PHARMACEUTICALSBy:
    
    /s/ Michael J. PuntorieroName:
    
    Michael J. PuntorieroTitle:
    
    Senior Vice President and Chief Financial Officer




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NEAL R. CUTLERBy:
    /s/ Neal R. CutlerNeal R. Cutler




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##### 



EXHIBIT A
CERTIFICATE OF PROPOSED TRANSFER




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CERTIFICATE OF PROPOSED TRANSFER
   
  1.
    
    The Transferee falls within one or more of the following categories (please initial one or
more, as applicable):
 
 
 
 2




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2.
    
    The Transferee is a sophisticated investor, knowledgeable, sophisticated and experienced in
business and financial matters. The Transferee is able to bear the economic risk of holding
the Note and the Common Stock for an indefinite period and is able to afford the complete loss
of his investment in the Note and the Common Stock.
 3.
    
    The Transferee has had the opportunity to consult and has been advised or has elected to
proceed without advise from his legal counsel and tax advisor in connection with his
acquisition of the Note and the Common Stock, and acknowledges that no representations as to
potential profit and tax consequences of any sort have been made by the Company, any officer
or any employee or representative or affiliate of the Company, and that projections and any
other information, including, without limitation, financial and descriptive information and
documentation, that may have been in any manner submitted to the Transferee shall not
constitute any representation or warranty of any kind or nature, express or implied.
 4.
    
    The Transferee has had access to certain financial and other information, including without
limitation the Companys most current Form 10-K and proxy statement and other filings with the
Securities and Exchange Commission available on the Companys website at
www.avanir.com and has been afforded the opportunity to ask questions of
representatives of the Company relating thereto, and to receive answers to those questions, as
the Transferee deemed necessary in connection with the acquisition of the Note and the Common
Stock. The Transferee has carefully considered potential risks relating to the Company and
the acquisition of the Note and the Common Stock.
 5.
    
    The Transferee acknowledges that it will acquire the Note and the Common Stock in
transactions not involving any public offering within the meaning of the Act and that the Note
and the shares of the Common Stock have not been registered under the Act (unless the sale of
the Common Stock shall have been registered under the Act, pursuant to the terms of that
certain Registration Rights Agreement dated May 24, 2006, by and between the Company and the
Holder (the Registration Rights Agreement).
 3




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6.
    
    The Transferee agrees not to offer, sell, transfer or otherwise dispose of the Note or the
Common Stock in the absence of registration under the Act unless, if requested by the Company,
the Transferee delivers to the Company an opinion of a lawyer experienced in securities law
matters and reasonably acceptable to the Company (it being understood that Milbank, Tweed,
Hadley & McCloy LLP shall be deemed acceptable to Payor) stating that in the opinion of the
attorney the proposed sale, transfer or other disposition is exempt from registration under
the Act and under all applicable state securities or blue sky laws.
 7.
    
    The Transferee acknowledges that the Note will bear a legend to the following effect:
  8.
    
    The Transferee acknowledges that the Common Stock will be in the form of physical
certificates and that the certificates will bear a legend to the following effect (unless the
sale of the Common Stock shall have been registered under the Act pursuant to the terms of the
Registration Rights Agreement):
  4




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9.
    
    The Transferee acknowledges that the Company may place a stop transfer order with its
transfer agent or registrar to enforce the provisions of Section 5 of the Note.
 10.
    
    The Transferee represents that it will acquire the Note and the Common Stock solely for his
own account for the purpose of investment only and not as a nominee or agent for any other
person and not with a view to, or for offer or sale in connection with, any distribution or
resale thereof, in whole or in part, in violation of the Act or state securities or blue sky
laws, without prejudice, however, to his right to sell or otherwise dispose of all or any part
of the Common Stock pursuant to an effective registration statement under the Act or under an
exemption from registration available under the Act.
 11.
    
    The Company is entitled to rely on this Certificate in connection with its obligations
pursuant to the Purchase Agreement and the Note.
  5




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HolderBy:Neal R. CutlerTransfereeBy: