ESHA 2000 (UK) - contains:
6.3 mg Ethacridine lactate, (AKA: Rivanol an antibacterial acridine, sometimes used to treat shigella.)
1 mg Proflavin, an acridine closely related to acriflavin and used for protozoans (velvet), gram positive bacteria, and fungus. 3.2 mg Copper ++ - Used for protozoans (ich and velvet). Note: Effective against parasites, but often toxic to fish, especially in soft water.
0.26 mg Methyl Orange - A multifunctional product.
I don't know exactly what levels of copper are a problem for shrimp but the typical advise is to avoid medications with copper.
If it's only the one fish, could you get it into a hospital tank?
I'd use salt as well as the Melafix. The salt (at around 0.3%) will reduce the osmotic pressure on the fish and reduce stress as well as having an anti-parasite effect. Fungus is a secondary infection meaning your fish has an open wound somewhere ans the salt will help treat this. You could also remove the fish and give it a bath of the anti-fungal treatment, then put it in fresh water to clean the medication off before returning to the tank.