when i was on Ab and nimidazoles i noticed that the main strength against CPN among nimidazoles was atrican 250 mg 3 times a day. Atrican without AB supressed CPN so strongly that were no pain at all. But it beats a bit on the head. Ornidazole was also good.
So my suggestion is to include atrican and ornidazole to CAP as alternative to old metronidazole and tinidazole