Most ich meds are tough on shrimp. Epecially those that contain copper. There's a quinone based med called Ich Attack, or something very similar that works but smells bad and makes a mess of your filter media. I used it once in the past when I couldn't get the fish out of the aquarium due to planting and multiple hiding spots.
There's also the heat method which works on most types of ich, but can be as tough or tougher on certain fish and especially on shrimp. Most people use a combination of heat and meds.
Some swear by salt, but my LFS salts the bejeepers out of their tanks and still have fish covered in ich.
IMO the best course of action is to put your fish (all of them) in the quarantine tank and use a copper based medication. Don't return the fish to the main tank for two weeks or better. If you return them sooner, or don't remove all of the fish, then it's almost certain that the tomites or trophonts will survive, and the parasite will persist in the tank at some level.
If you have no choice, and find that you must treat the fish in the main tank, continue the treatment for several weeks, at least two, but preferably for a month. The problem with treating in the main tank will be trying to prevent trophonts on the substrate from surviving the treatment.