delete table prefix

// all database
SELECT CONCAT( 'DROP TABLE ', GROUP_CONCAT(table_name) , ';' )
    AS statement FROM information_schema.tables
    WHERE table_name LIKE 'myprefix_%';

// specific database
SELECT CONCAT( 'DROP TABLE ', GROUP_CONCAT(table_name) , ';' )
    AS statement FROM information_schema.tables
    WHERE table_schema = 'database_name' AND table_name LIKE 'myprefix_%';