Yes, a demand letter can be revised after the initial loan disbursement under certain conditions, such as a change in your financial need, a modification in tuition fees by the educational institution, or an adjustment in your study program. To initiate this process, you would need to contact your lender with the new information and request a revision of the loan terms. The lender will then assess the new circumstances before agreeing to revise the demand letter and adjust the loan agreement accordingly.