<PAGE>

                                   EXHIBIT 4.2

                                                                   CLS G WNT #14


THIS WARRANT AND THE SHARES ISSUABLE UPON THE EXERCISE OF THIS WARRANT HAVE NOT
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. EXCEPT AS
OTHERWISE SET FORTH HEREIN, NEITHER THIS WARRANT NOR ANY OF SUCH SHARES MAY BE
SOLD, OFFERED FOR SALE, ASSIGNED, TRANSFERRED, OR OTHERWISE DISPOSED OF IN THE
ABSENCE OF REGISTRATION UNDER SUCH ACT OR AN OPINION OF COUNSEL THAT
REGISTRATION IS NOT REQUIRED UNDER SUCH ACT OR UNLESS SOLD PURSUANT TO RULE 144
UNDER SUCH ACT. ANY SUCH SALE, ASSIGNMENT OR TRANSFER MUST ALSO COMPLY WITH
APPLICABLE STATE SECURITIES LAWS.

                                             Right to Purchase 757,050 Shares of
                                              Class A Common Stock, no par value

                                     CLASS G
                           STOCK PURCHASE WARRANT #14

         THIS CERTIFIES THAT, for value received, RGC INTERNATIONAL INVESTORS,
LDC, a Cayman Islands corporation, or its registered assigns (the "Holder"), is
entitled to purchase from AVANIR PHARMACEUTICALS, a California corporation
(formerly LIDAK Pharmaceuticals, the "Company"), at any time or from time to
time during the period specified in Paragraph 2 hereof, SEVEN HUNDRED
FIFTY-SEVEN THOUSAND FIFTY (757,050) fully paid and nonassessable shares of the
Company's Class A Common Stock, no par value ("Common Stock"), at an exercise
price of $1.375 per share (the "Exercise Price"). The term "Warrant Shares", as
used herein, refers to the shares of Common Stock purchasable hereunder. The
Warrant Shares and the Exercise Price are subject to adjustment as provided in
Paragraph 4 hereof. The term Warrant means this Warrant, which replaces all
other warrants of the Company previously issued upon conversions from time to
time of the Convertible Note, dated February 26, 1997 and issued by the Company
(the "Note"). Such other warrants are hereby terminated and listed below as
follows:

Warrants Being Terminated:

<TABLE>
<CAPTION>
           Number          Granted          Price          Issue Date
           ------          -------          -----          ----------
<S>                      <C>                <C>            <C>
           G00013        4,385,783          $1.375          08/23/99
</TABLE>
<PAGE>
         This Warrant is subject to the following terms, provisions, and
conditions:

         1. MANNER OF EXERCISE; ISSUANCE OF CERTIFICATES; PAYMENT FOR SHARES.
Subject to the provisions hereof, this Warrant may be exercised by the Holder,
in whole or in part, by the surrender of this Warrant, together with a completed
exercise agreement in the form attached hereto (the "Exercise Agreement"), to
the Company during normal business hours on any business day at the Company's
principal executive offices (or such other office or agency of the Company as it
may designate by notice to the Holder), and upon (i) payment to the Company in
cash, by certified or official bank check or by wire transfer for the account of
the Company of the Exercise Price for the Warrant Shares specified in the
Exercise Agreement or (ii) if the resale of the Warrant Shares by the Holder is
not then registered pursuant to an effective registration statement under the
Securities Act of 1933, as amended (the "1933 Act"), delivery to the Company of
a written notice of an election to effect a "Cashless Exercise" (as defined in
Section 11(c) below) for the unregistered Warrant Shares specified in the
Exercise Agreement. The Warrant Shares so purchased shall be deemed to be issued
to the Holder or the Holder's designee, as the record owner of such shares, as
of the close of business on the date on which this Warrant shall have been
surrendered, the completed Exercise Agreement shall have been delivered, and
payment shall have been made for such shares as set forth above. Certificates
for the Warrant Shares so purchased, representing the aggregate number of shares
specified in the Exercise Agreement, shall be delivered to the Holder within a
reasonable time, not exceeding three (3) business days, after this Warrant shall
have been so exercised. The certificates so delivered shall be in such
denominations as may be requested by the Holder and shall be registered in the
name of the Holder or such other name as shall be designated by the Holder. If
this Warrant shall have been exercised only in part, then, unless this Warrant
has expired, the Company shall, at its expense, at the time of delivery of such
certificates, deliver to the Holder a new Warrant representing the number of
shares with respect to which this Warrant shall not then have been exercised.

         Notwithstanding anything in this Warrant to the contrary, in no event
shall the Holder be entitled to exercise a number of Warrants (or portions
thereof) in excess of the number of Warrants (or portions thereof) upon exercise
of which the sum of (i) the number of shares of Common Stock beneficially owned
by the Holder and its affiliates (other than shares of Common Stock which may be
deemed beneficially owned through the ownership of the unexercised Warrants) and
(ii) the number of shares of Common Stock issuable upon exercise of the Warrants
(or portions thereof) with respect to which the determination described herein
is being made, would result in beneficial ownership by the Holder and its
affiliates of more than 4.9% of the outstanding shares of Common Stock. For
purposes of the immediately preceding sentence, beneficial ownership shall be
determined in accordance with Section 13(d) of the Securities Exchange Act of
1934, as amended, and Regulation 13D-G thereunder.

         2. PERIOD OF EXERCISE. This Warrant is exercisable at any time or from
time to time on or after the date hereof, but before 5:00 p.m., New York City
time, on the

                                       2
<PAGE>
sixtieth day following the date of effectiveness of a registration statement
registering the resale by the Holder of the Warrant Shares issuable hereunder
(the "Exercise Period").

         3. CERTAIN AGREEMENTS OF THE COMPANY. The Company hereby covenants and
agrees as follows:

                  (a) SHARES TO BE FULLY PAID. All Warrant Shares will, upon
issuance in accordance with the terms of this Warrant, be validly issued, fully
paid, and nonassessable and free from all taxes, liens, and charges with respect
to the issue thereof.

                  (b) RESERVATION OF SHARES. During the Exercise Period, the
Company shall at all times have authorized, and reserved for the purpose of
issuance upon exercise of this Warrant, a sufficient number of shares of Common
Stock to provide for the exercise of this Warrant.

                  (c) LISTING. The Company shall promptly secure the listing of
the shares of Common Stock issuable upon exercise of the Warrant upon each
national securities exchange or automated quotation system, if any, upon which
shares of Common Stock are then listed (subject to official notice of issuance
upon exercise of this Warrant) and shall maintain, so long as any other shares
of Common Stock shall be so listed, such listing of all shares of Common Stock
from time to time issuable upon the exercise of this Warrant; and the Company
shall so list on each national securities exchange or automated quotation
system, as the case may be, and shall maintain such listing of, any other shares
of capital stock of the Company issuable upon the exercise of this Warrant if
and so long as any shares of the same class shall be listed on such national
securities exchange or automated quotation system.

                  (d) CERTAIN ACTIONS PROHIBITED. The Company will not, by
amendment of its charter or through any reorganization, transfer of assets,
consolidation, merger, dissolution, issue or sale of securities, or any other
voluntary action, avoid or seek to avoid the observance or performance of any of
the terms to be observed or performed by it hereunder, but will at all times in
good faith assist in the carrying out all of the provisions of this Warrant and
in the taking all such actions as may reasonably be requested by the Holder in
order to protect the exercise privilege of the Holder against dilution or other
impairment, consistent with the tenor and purpose of this Warrant. Without
limiting the generality of the foregoing, the Company (i) will not increase the
par value of any shares of Common Stock receivable upon the exercise of this
Warrant above the Exercise Price then in effect, and (ii) will take all such
actions as may be necessary or appropriate in order that the Company may validly
and legally issue fully paid and nonassessable shares of Common Stock upon the
exercise of this Warrant.

                  (e) SUCCESSORS AND ASSIGNS. This Warrant will be binding upon
any entity succeeding to the Company by merger, consolidation, or acquisition of
all or substantially all the Company's assets.

                                       3
<PAGE>
         4. ANTIDILUTION PROVISIONS. During the Exercise Period, the Exercise
Price and the number of Warrant Shares shall be subject to adjustment from time
to time as provided in this Paragraph 4.


                  (A) ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF SHARES UPON
ISSUANCE OF COMMON STOCK. If the Company issues or sells any shares of Common
Stock in accordance with Paragraphs 4(b) or 4(d) (a "Dilutive Issuance"), then
immediately upon the Dilutive Issuance, the Exercise Price will be adjusted in
the manner described in the applicable Paragraph 4(b) or 4(d).

                  (B) SUBDIVISION OR COMBINATION OF COMMON STOCK. If the Company
at any time subdivides (by any stock split, stock dividend, recapitalization,
reorganization, reclassification or otherwise) the shares of Common Stock
acquirable hereunder into a greater number of shares, then, after the date of
record for effecting such subdivision, the Exercise Price in effect immediately
prior to such subdivision will be proportionately reduced. If the Company at any
time combines (by reverse stock split, recapitalization, reorganization,
reclassification or otherwise) the shares of Common Stock acquirable hereunder
into a smaller number of shares, then, after the date of record for effecting
such combination, the Exercise Price in effect immediately prior to such
combination will be proportionately increased.

                  (C) ADJUSTMENT IN NUMBER OF SHARES. Upon each adjustment of
the Exercise Price pursuant to the provisions of this Paragraph 4, the number of
shares of Common Stock issuable upon exercise of this Warrant shall be adjusted
by multiplying a number equal to the Exercise Price in effect immediately prior
to such adjustment by the number of shares of Common Stock issuable upon
exercise of this Warrant immediately prior to such adjustment and dividing the
product so obtained by the adjusted Exercise Price.

                  (D) CONSOLIDATION, MERGER OR SALE. In case of any
consolidation of the Company with, or merger of the Company into any other
corporation, or in case of any sale or conveyance of all or substantially all of
the assets of the Company other than in connection with a plan of complete
liquidation of the Company, then as a condition of such consolidation, merger or
sale or conveyance, adequate provision will be made whereby the Holder will have
the right to acquire and receive upon exercise of this Warrant in lieu of the
shares of Common Stock immediately theretofore acquirable upon the exercise of
this Warrant, such shares of stock, securities or assets as may be issued or
payable with respect to or in exchange for the number of shares of Common Stock
immediately theretofore acquirable and receivable upon exercise of this Warrant
had such consolidation, merger or sale or conveyance not taken place. In any
such case, the Company will make appropriate provision to insure that the
provisions of this Paragraph 4 hereof will thereafter be applicable as nearly as
may be in relation to any shares of stock or securities thereafter deliverable
upon the exercise of this Warrant. The Company will not effect any
consolidation, merger or sale or conveyance unless prior to the consummation
thereof, the successor corporation (if other than the Company) assumes

                                       4
<PAGE>
by written instrument the obligations under this Paragraph 4 and the obligations
to deliver to the Holder such shares of stock, securities or assets as, in
accordance with the foregoing provisions, the Holder may be entitled to acquire.

                  (E) DISTRIBUTION OF ASSETS. In case the Company shall declare
or make any distribution of its assets (including cash) to holders of Common
Stock as a partial liquidating dividend, by way of return of capital or
otherwise, then, after the date of record for determining stockholders entitled
to such distribution, but prior to the date of distribution, the Holder shall be
entitled upon exercise of this Warrant for the purchase of any or all of the
shares of Common Stock subject hereto, to receive the amount of such assets
which would have been payable to the Holder had the Holder been the holder of
such shares of Common Stock on the record date for the determination of
stockholders entitled to such distribution.

                  (F) NOTICE OF ADJUSTMENT. Upon the occurrence of any event
which requires any adjustment of the Exercise Price, then, and in each such
case, the Company shall give notice thereof to the Holder, which notice shall
state the Exercise Price resulting from such adjustment and the increase or
decrease in the number of Warrant Shares purchasable at such price upon
exercise, setting forth in reasonable detail the method of calculation and the
facts upon which such calculation is based. Such calculation shall be certified
by the chief financial officer of the Company.

                  (G) MINIMUM ADJUSTMENT OF EXERCISE PRICE. No adjustment of the
Exercise Price shall be made in an amount of less than 1% of the Exercise Price
in effect at the time such adjustment is otherwise required to be made, but any
such lesser adjustment shall be carried forward and shall be made at the time
and together with the next subsequent adjustment which, together with any
adjustments so carried forward, shall amount to not less than 1% of such
Exercise Price.

                  (H) NO FRACTIONAL SHARES. No fractional shares of Common Stock
are to be issued upon the exercise of this Warrant, but the Company shall pay a
cash adjustment in respect of any fractional share which would otherwise be
issuable in an amount equal to the same fraction of the Market Price of a share
of Common Stock on the date of such exercise.

                  (I) OTHER NOTICES. In case at any time:

                        (1) the Company shall declare any dividend upon the
Common Stock payable in shares of stock of any class or make any other
distribution (including dividends or distributions payable in cash out of
retained earnings) to the holders of the Common Stock;

                        (2) the Company shall offer for subscription pro rata to
the holders of the Common Stock any additional shares of stock of any class or
other rights;

                                       5
<PAGE>
                        (3) there shall be any capital reorganization of the
Company, or reclassification of the Common Stock, or consolidation or merger of
the Company with or into, or sale of all or substantially all its assets to,
another corporation or entity; or

                        (4) there shall be a voluntary or involuntary
dissolution, liquidation or winding up of the Company:

then, in each such case, the Company shall give to the Holder (a) notice of the
date on which the books of the Company shall close or a record shall be taken
for determining the holders of Common Stock entitled to receive any such
dividend, distribution, or subscription rights or for determining the holders of
Common Stock entitled to vote in respect of any such reorganization,
reclassification, consolidation, merger, sale, dissolution, liquidation or
winding-up and (b) in the case of any such reorganization, reclassification,
consolidation, merger, sale, dissolution, liquidation or winding-up, notice of
the date (or, if not then known, a reasonable approximation thereof by the
Company) when the same shall take place. Such notice shall also specify the date
on which the holders of Common Stock shall be entitled to receive such dividend,
distribution, or subscription rights or to exchange their Common Stock for stock
or other securities or property deliverable upon such reorganization,
reclassification, consolidation, merger, sale, dissolution, liquidation, or
winding-up, as the case may be. Such notice shall be given at least 15 days
prior to the record date or the date on which the Company's books are closed in
respect thereto. Failure to give any such notice or any defect therein shall not
affect the validity of the proceedings referred to in clauses (i), (ii), (iii)
and (iv) above.

                  (J) CERTAIN EVENTS. If any event occurs of the type
contemplated by the adjustment provisions of this Paragraph 4 but not expressly
provided for by such provisions, the Company will give notice of such event as
provided in Paragraph 4(f) hereof, and the Company's Board of Directors will
make an appropriate adjustment in the Exercise Price and the number of shares of
Common Stock acquirable upon exercise of this Warrant so that the rights of the
Holder shall be neither enhanced nor diminished by such event.

                  (K) CERTAIN DEFINITIONS.

                        (1) "COMMON STOCK DEEMED OUTSTANDING" shall mean the
number of shares of Common Stock actually outstanding (not including shares of
Common Stock held in the treasury of the Company).

                        (2) "MARKET PRICE," as of any date, (i) means the
average of the last reported sale prices for the shares of Common Stock as
reported by The American Stock Exchange ("AMEX") for the ten (10) trading days
immediately preceding such date, or (ii) if the AMEX is not the principal
trading market for the shares of Common Stock, the average of the last reported
sale prices on the principal trading market for the Common Stock during the same
period, or (iii) if market value cannot be calculated as of such date on any of
the foregoing bases, the Market Price shall be the fair market value

                                       6
<PAGE>
as reasonably determined in good faith by (a) the Board of Directors of the
Corporation or, at the option of a majority-in-interest of the holders of the
outstanding Warrants by (b) an independent investment bank of nationally
recognized standing in the valuation of businesses similar to the business of
the corporation. The manner of determining the Market Price of the Common Stock
set forth in the foregoing definition shall apply with respect to any other
security in respect of which a determination as to market value must be made
hereunder.

                        (3) "COMMON STOCK," for purposes of this Paragraph 4,
includes the Class A Common Stock, no par value, and any additional class of
stock of the Company having no preference as to dividends or distributions on
liquidation, provided that the shares purchasable pursuant to this Warrant shall
include only shares of Common Stock, no par value, in respect of which this
Warrant is exercisable, or shares resulting from any subdivision or combination
of such Common Stock, or in the case of any reorganization, reclassification,
consolidation, merger, or sale of the character referred to in Paragraph 4(d)
hereof, the stock or other securities or property provided for in such
Paragraph.

         5. ISSUE TAX. The issuance of certificates for Warrant Shares upon the
exercise of this Warrant shall be made without charge to the Holder or such
shares for any issuance tax or other costs in respect thereof, provided that the
Company shall not be required to pay any tax which may be payable in respect of
any transfer involved in the issuance and delivery of any certificate in a name
other than the Holder.

         6. NO RIGHTS OR LIABILITIES AS A SHAREHOLDER. This Warrant shall not
entitle the Holder to any voting rights or other rights as a shareholder of the
Company. No provision of this Warrant, in the absence of affirmative action by
the Holder to purchase Warrant Shares, and no mere enumeration herein of the
rights or privileges of the Holder, shall give rise to any liability of the
Holder for the Exercise Price or as a shareholder of the Company, whether such
liability is asserted by the Company or by creditors of the Company.

         7. TRANSFER, EXCHANGE, AND REPLACEMENT OF WARRANT.

                  (A) RESTRICTION ON TRANSFER. This Warrant and the related
rights granted to the Holder are transferable, in whole or in part, upon
surrender of this Warrant, together with a properly executed assignment in the
form attached hereto, at the office or agency of the Company referred to in
Paragraph 7(e) below; provided, however, that any transfer or assignment of this
Warrant and the related rights granted to the Holder, in whole or in part, shall
(i) cover not less than 100,000 Warrant Shares and (ii) be subject to the
conditions set forth in Paragraphs 7(f) and 7(g). Until due presentment for
registration of transfer on the books of the Company, the Company may treat the
registered Holder as the owner and holder hereof for all purposes, and the
Company shall not be affected by any notice to the contrary.

                                       7
<PAGE>
                  (B) WARRANT EXCHANGEABLE FOR DIFFERENT DENOMINATIONS. This
Warrant is exchangeable, upon the surrender hereof by the Holder at the office
or agency of the Company referred to in Paragraph 7(e) below, for new Warrants
of like tenor representing in the aggregate the right to purchase the number of
shares of Common Stock which may be purchased hereunder, each of such new
Warrants to represent the right to purchase such number of shares as shall be
designated by the Holder at the time of such surrender.

                  (C) REPLACEMENT OF WARRANT. Upon receipt of evidence
reasonably satisfactory to the Company of the loss, theft, destruction, or
mutilation of this Warrant and, in the case of any such loss, theft, or
destruction, upon delivery of an indemnity agreement reasonably satisfactory in
form and amount to the Company, or, in the case of any such mutilation, upon
surrender and cancellation of this Warrant, the Company, at its expense, will
execute and deliver, in lieu thereof, a new Warrant of like tenor.

                  (D) CANCELLATION; PAYMENT OF EXPENSES. Upon the surrender of
this Warrant in connection with any transfer, exchange, or replacement as
provided in this Paragraph 7, this Warrant shall be promptly canceled by the
Company. The Company shall pay all taxes (other than securities transfer taxes)
and all other expenses (other than legal expenses, if any, incurred by the
Holder or transferees) and charges payable in connection with the preparation,
execution, and delivery of Warrants pursuant to this Paragraph 7.

                  (E) REGISTER. The Company shall maintain, at its principal
executive offices (or such other office or agency of the Company as it may
designate by notice to the Holder), a register for this Warrant, in which the
Company shall record the name and address of the person in whose name this
Warrant has been issued, as well as the name and address of each transferee and
each prior owner of this Warrant.

                  (F) EXERCISE OR TRANSFER WITHOUT REGISTRATION. If, at the time
of the surrender of this Warrant in connection with any exercise, transfer, or
exchange of this Warrant, this Warrant (or, in the case of any exercise, the
Warrant Shares issuable hereunder), shall not be registered under the 1933 Act
and under applicable state securities or blue sky laws, the Company may require,
as a condition of allowing such exercise, transfer, or exchange, (i) that the
Holder or transferee of this Warrant, as the case may be, furnish to the Company
a written opinion of counsel, which opinion and counsel are reasonably
acceptable to the Company, to the effect that such exercise, transfer, or
exchange may be made without registration under said Act and under applicable
state securities or blue sky laws, (ii) that the Holder or transferee execute
and deliver to the Company an investment letter in form and substance reasonably
acceptable to the Company and (iii) that the transferee be an "accredited
investor" as defined in Rule 501(a) promulgated under the 1933 Act; provided
that no such opinion, letter, status as an "accredited investor" or aggregate
Market Price condition shall be required in connection with a transfer pursuant
to Rule 144 under the 1933 Act. The first Holder of this Warrant, by taking and
holding the same, represents to the Company that such

                                       8
<PAGE>
Holder is acquiring this Warrant for investment and not with a view to the
distribution thereof.

                  (G) RIGHT OF FIRST OFFER. Subject to the terms and conditions
specified in this Section 7, the Holder hereby grants to the Company a right of
first offer with respect to any future sale, transfer or assignment by the
Holder of this Warrant and the rights granted hereunder, in whole or in part.
Each time the Holder proposes to offer this Warrant and the rights granted
hereunder, in whole or in part, for sale, transfer or assignment (the "Offered
Warrant"), the Holder will first make an offering of the Offered Warrant to the
Company in accordance with the following provisions:

                        (I) NOTICE. The Holder will deliver notice (the "Offer
Notice") to the Company stating (i) its bona fide intention to offer the Offered
Warrant, and (ii) the price and terms upon which it proposes to offer the
Offered Warrant; and

                        (II) MECHANICS. Within ten (10) business days after its
receipt of the Offer Notice (the "Election Period"), the Company may elect to
purchase or obtain, at the price and on the terms specified in the Offer Notice,
the Offered Warrant. In the event that the Company does not elect to purchase or
obtain the Offered Warrant as specified in the Offer Notice within the Election
Period, the Company may, during the 45 calendar days following the expiration of
the Election Period, sell the Offered Warrant to any person or persons at a
price not less than that, and upon terms no more favorable than those, specified
in the Offer Notice. If the Holder does not sell the Offered Warrant within such
45-calendar day period, then the right of first offer provided pursuant to this
Paragraph 7(g) will be deemed to be revived and the Offered Warrant will not be
offered unless again reoffered to the Company in accordance with this Paragraph
7(g).

                  (H) CERTAIN RIGHT TO PLEDGE. The provisions of Paragraphs
7(a), 7(f) and 7(g) shall not apply with respect to, and nothing herein shall
limit or in any way affect, the right to pledge this Warrant in connection with
a bona fide margin account or lending arrangement.

         8. REGISTRATION RIGHTS. The Company is not obligated to register the
shares of Common Stock purchasable upon exercise of this Warrant. Therefore, to
the extent the Warrant Shares have not been registered for resale by the Holder,
they must bear a restrictive legend and may only be re-sold at the present time
under the SEC's Rule 144. The Company intends to register the Warrant Shares for
resale in the future at a time to be determined by the Company's board of
directors. However, the Company cannot assure the Holder that the Company will
be able to register the Warrant Shares on a timely basis, if at all.

         9. NOTICES. All notices, requests, and other communications required or
permitted to be given or delivered hereunder to the Holder shall be in writing,
and shall be personally delivered, or shall be sent by certified or registered
mail or by recognized overnight mail courier, postage prepaid and addressed, to
the Holder at the address shown for the Holder on the books of the Company, or
at such other address as shall

                                       9
<PAGE>
have been furnished to the Company by notice from the Holder. All notices,
requests, and other communications required or permitted to be given or
delivered hereunder to the Company shall be in writing, and shall be personally
delivered, or shall be sent by certified or registered mail or by recognized
overnight mail courier, postage prepaid and addressed, to the office of the
Company at 11388 Sorrento Valley Road, San Diego, CA 92121, Attention: Chief
Financial Officer or at such other address as shall have been furnished to the
Holder by notice from the Company. Any such notice, request, or other
communication may be sent by facsimile, but shall in such case be subsequently
confirmed by a writing personally delivered or sent by certified or registered
mail or by recognized overnight mail courier as provided above. All notices,
requests, and other communications shall be deemed to have been given either at
the time of the receipt thereof by the person entitled to receive such notice at
the address of such person for purposes of this Paragraph 9, or, if mailed by
registered or certified mail or with a recognized overnight mail courier upon
deposit with the United States Post Office or such overnight mail courier, if
postage is prepaid and the mailing is properly addressed, as the case may be.

         10. GOVERNING LAW. THIS WARRANT SHALL BE GOVERNED BY AND CONSTRUED AND
ENFORCED IN ACCORDANCE WITH THE INTERNAL LAWS OF THE STATE OF CALIFORNIA WITHOUT
REGARD TO THE BODY OF LAW CONTROLLING CONFLICTS OF LAW.

         11. MISCELLANEOUS.

                  (A) AMENDMENTS. This Warrant and any provision hereof may only
be amended by an instrument in writing signed by the Company and the Holder.

                  (B) DESCRIPTIVE HEADINGS. The descriptive headings of the
several paragraphs of this Warrant are inserted for purposes of reference only,
and shall not affect the meaning or construction of any of the provisions
hereof.

                  (C) CASHLESS EXERCISE OF UNREGISTERED SHARES. Notwithstanding
anything to the contrary contained in this Warrant, if the resale of the Warrant
Shares by the Holder is not then registered pursuant to an effective
registration statement under the 1933 Act, that portion of the Warrant Shares
which are not registered may be exercised by presentation and surrender of this
Warrant to the Company at its principal executive offices with a written notice
of the Holder's intention to effect a cashless exercise for the unregistered
shares, including a calculation of the number of shares of Common Stock to be
issued upon such exercise in accordance with the terms hereof (a "Cashless
Exercise"). In the event of a Cashless Exercise, a price of $2.97 per share
shall be used to determine the number of shares of Common Stock issuable upon
exercise of the unregistered Warrant Shares. To execute the Cashless Exercise,
the Holder shall surrender this Warrant for that number of shares of Common
Stock determined by multiplying the number of Warrant Shares to which it would
otherwise be entitled by a fraction, the numerator of which shall be the
difference between the then current Market Price per share of the Common Stock
and $2.97, and

                                       10
<PAGE>
the denominator of which shall be the then current Market Price per share of
Common Stock.

                  IN WITNESS WHEREOF, the Company has caused this Warrant to be
signed by its duly authorized officer.

DATED: OCTOBER 6, 2000

                                   AVANIR PHARMACEUTICALS


                                   By:  /s/ Gregory P. Hanson
                                        --------------------------
                                   Name:  Gregory P. Hanson
                                   Title: Vice President, Finance
                                          Chief Financial Officer

AGREED AND ACCEPTED:
RGC INTERNATIONAL INVESTORS, LDC

         BY:  ROSE GLEN CAPITAL MANAGEMENT, LDC

         BY:  RGC GENERAL PARTNER CORP.

         BY:  /s/ Steve Katznelson
            -----------------------------
         TITLE: Managing Director
               --------------------------
         DATED: October 6, 2000
               --------------------------

                                       11
<PAGE>
                           FORM OF EXERCISE AGREEMENT

                                                          Dated: ________ , ___.


TO:  AVANIR PHARMACEUTICALS

         The undersigned, pursuant to the provisions set forth in the within
Warrant, hereby agrees to purchase           shares of Common Stock covered by
such Warrant, and makes payment herewith in full therefor at the price per share
provided by such Warrant in cash or by certified or official bank check in the
amount of, or, if the resale of such Common Stock by the undersigned is not
currently registered pursuant to an effective registration statement under the
Securities Act of 1933, as amended, by surrender of securities issued by the
Company (including a portion of the Warrant) having a market value (in the case
of a portion of this Warrant, determined in accordance with Section 11(c) of the
Warrant) equal to $1.375. Please issue a certificate or certificates for such
shares of Common Stock in the name of and pay any cash for any fractional share
to:

                   Name: ___________________________________

                   Signature: ______________________________

                   Address: ________________________________

                   __________________________________________



         Note: The above signature should correspond exactly with the name on
the face of the within Warrant.

and, if said number of shares of Common Stock shall not be all the shares
purchasable under the within Warrant, a new Warrant is to be issued in the name
of said undersigned covering the balance of the shares purchasable thereunder
less any fraction of a share paid in cash.

                                       12
<PAGE>
                               FORM OF ASSIGNMENT

         FOR VALUE RECEIVED, the undersigned hereby sells, assigns, and
transfers all the rights of the undersigned under the within Warrant, with
respect to the number of shares of Common Stock covered thereby set forth herein
below, to:

<TABLE>
<CAPTION>
Name of Assignee           Address          No of Shares
----------------           -------          ------------
<S>                        <C>              <C>

</TABLE>

, and hereby irrevocably constitutes and appoints ______________________ as
agent and attorney-in-fact to transfer said Warrant on the books of the
within-named corporation, with full power of substitution in the premises.

Dated: ________ , ___.

In the presence of


                   Name:

                   Signature:


                   Title of Signing Officer or Agent (if any):

                   Address:


                  Note: The above signature should correspond exactly with the
name on the face of the within Warrant.

                                       13