TRUNCATE and DROP Command not working in temporary table

I am using Oracle DB
I am trying to Truncate and DROP all the available temporary table in for each row,
but after truncate query, when in execute query drop command is used I’m getting an error that

Execute Query: ERROR [HY000] [Oracle][ODBC][Ora]ORA-14452: attempt to create, alter or drop an index on temporary table already in use.

Please Advice.