I'm trying this food out with a fish I have with a sunken stomach. Not sure how it works yet. It has metro, Epsom salt, garlic and levamisole.
Good mix for deworming a fish, but won't help if the fish is suffering from Spironucleus aka Hexamita, which I can only assume is what the issue is with the OP's fish. There is no Metro listed? Active ingredients are levamisole, praziquantel, epsom salt and garlic .
If it was a tapeworm then 2 weeks of PraziPro would have resolved that issue. Could still be nematodes, which would require a different deworming agent, such as Levamisole - but seems to me to be more gastrointestinal, some form of internal parasite, possibly a chronic case of hex.
Personally I would go this route ...….
levamisole is different from metronidazole, and they both treat different parasites. Metro is best ingested, so getting Seachem focus and Seachem metroplex, and mixing in bloodworm into a dry paste. If you can get API general cure now, treat the water, and then get the other. If you don't see improvements in 2 weeks, then purchase levamisole, which is sold as cattle dewormer Prohibit.