FAQ: I'm using a different anti parasitic medication and it doesn't seem to be working. Should I swap to Seachem Cupramine™?

Possibly. There are many situations where it is necessary to change medication.  Sometimes you are treating a parasite that is very medication resistant and requires a more powerful treatment, other times the medication you were using was simply the wrong kind to treat the infection.  However, there are a few things that MUST be true before making this kind of swap.

1. You have given your original medication enough time to work. The visible cysts caused by ich and other external parasites are all but immune to medication, and can take up to a week to drop off the fish when using a medication. In fact, ich infestations often look worse before they get better. Don't swap medications just because your current treatment did not cure the fish in a single day.
2. You are certain that you are treating ich, velvet, or a similar external parasite. Sometimes, an anti-parasitic medication will fail to work because you are not actually treating a parasite. Viral infections like lymphocystis and several types of bacterial infections will show similar symptoms to ich (white cysts in the case of lymphocystis and skin irritation and flashing in the case of bacterial infections.) Research your fish's symptoms thoroughly to ensure that you are choosing the right kind of medication.
3. Your fish and other aquarium inhabitants will tolerate a copper-based medication. Medications like MetroPlex™ can be added to a fish food to make an ich treatment that is safe to use in reef or planted aquaria.  Unfortunately, Cupramine™ is not considered safe for this kind of aquarium.  Likewise, many fish are sensitive to medications and must be treated with a gentle medication like ParaGuard™ to prevent stress. 
4. You are not using a product that will interfere with Cupramine™. An aquarium that is being treated with Cupramine™ should never be dosed with a reducing agent. Some common reducing agents are water conditioners, ammonia detoxifiers, stress reducers, and some water clarifiers and multi-purpose buffers (buffers that remove chlorine and chloramine). For  more information on products that should not be used with Cupramine™, check out FAQ: Can I use Cupramine™ together with _____?