Rename the constraint of a possibly referenced primary key in PostgreSQL

Is it safe to use this command just like that, even though the table might be referenced from other tables as foreign key?

ALTER INDEX foo_pkey RENAME TO pk__foo__id;

I have just tried it and it seems OK, but I have heard it is necessary to drop foreign keys, rename pkey (drop/recreate) and re-reference the table again.

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In case it is not that easy, is there a way how to find all referencing tables, drop their fkeys, alter the index and atach them again in one SQL?

Here is what I am using to find tables and their fkeys referencing my table:

SELECT
    tc.table_name, tc.constraint_name, kcu.column_name,
    ccu.table_name AS foreign_table_name,
    ccu.column_name AS foreign_column_name
FROM
    information_schema.table_constraints AS tc
    JOIN information_schema.key_column_usage AS kcu
      ON tc.constraint_name = kcu.constraint_name
    JOIN information_schema.constraint_column_usage AS ccu
      ON ccu.constraint_name = tc.constraint_name
WHERE constraint_type = 'FOREIGN KEY' AND ccu.table_name ='foo';