Former Prisoners of War Special Compensation Act of 2003 - Directs the Secretary of Veterans Affairs to pay special monthly compensation to each veteran who is a former prisoner of war and was detained or interned for at least 30 days. Provides various rates of payment, ranging from $150 for those detained for between 30 and 120 days to a maximum of $450 for those detained more than 540 days. States that such special compensation shall: (1) be in addition to any other authorized payments; and (2) shall not be considered income for purposes of eligibility under any Federal or federally assisted program.Prohibits the payment of veterans' disability compensation for any alcohol- or drug-related disability even if the abuse is secondary to a service-connected disability.Removes the requirement that former prisoners of war must have been detained or interned for at least 90 days in order to be eligible for veterans' outpatient dental care.