<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="http://www.RRDnetfiler.com/XSL/SEC_Form_4.xsl"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

<documentType>4</documentType>
<periodOfReport>2003-05-05</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
<issuer><issuerCik>0001040416</issuerCik>
        <issuerName>INSPIRE PHARMACEUTICALS INC</issuerName>
<issuerTradingSymbol>ISPH</issuerTradingSymbol></issuer>
<reportingOwner>
<reportingOwnerId>
<rptOwnerCik>0001230708</rptOwnerCik>
            <rptOwnerName>STAAB THOMAS R II</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
<reportingOwnerRelationship>
<isDirector>0</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>Chief Financial Officer</officerTitle>
<otherText></otherText></reportingOwnerRelationship></reportingOwner>
<derivativeSecurity>
<securityTitle>
<value>Employee Stock Option (Right to Buy)</value></securityTitle>
<conversionOrExercisePrice>
<value>14.71</value></conversionOrExercisePrice>
<transactionDate>
<value>2003-05-05</value></transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>A</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved></transactionCoding>
<transactionAmounts>
<transactionShares>
<value>50000</value></transactionShares>
<transactionValue>
<value>0.00</value></transactionValue>
<transactionAcquiredDisposedCode>
<value>A</value></transactionAcquiredDisposedCode></transactionAmounts>
<exerciseDate>
<value>2004-05-05</value>
<footnoteId id="F1"/></exerciseDate>
<expirationDate>
<value>2013-05-05</value></expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Common Stock</value></underlyingSecurityTitle>
<underlyingSecurityShares>
<value>50000</value></underlyingSecurityShares></underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>50000</value></sharesOwnedFollowingTransaction></postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value></directOrIndirectOwnership>
<natureOfOwnership>
<value></value></natureOfOwnership></ownershipNature></derivativeSecurity>
<footnotes>
<footnote id="F1">Exercisable as to 12,500 shares on May 5, 2004 and as to 1/48 on the last day of each month thereafter until fully vested.</footnote></footnotes>
<ownerSignature>
<signatureName>Thomas R. Staab, II</signatureName>
<signatureDate>2003-05-07</signatureDate></ownerSignature></ownershipDocument>


