Different countries have different medications on their market. Fish medication is no exception what is available here in the United Kingdom may not be available in the United States, and vice versa. For this reason, it is sometimes difficult for me to recommend something to someone who doesn't live in this country. With the help of Chile from Oscarfish, I can list three medications that can be used on severe cases of hole in the head. Like I have already said on another page, hole in the head disease can be cured and prevented with regular tank maintenance and a healthy diet. Some people like to feed their fish vitamins, rather like human beings, there's a lot of controversy with vitamins so they may or may not work. If you do notice little holes or pits appearing on your fishers head, or around the front of its body, up your tank maintenance and keep a very close eye on the water quality. If all else fails, try medication. The next three listed medications are available in the United States

Jungle Lab's 'Hole-n-Head Guard'

Thomas Laboratories 'Fish Zole'

Aquarium Solutions 'Metro+

Good luck

There is an unproven theory also that activated charcoal may assist in causing it. Who knows?
But I tend to think it's more stress related or bad water conditions for both erode the immune system.

I think poor water conditions probably play the biggest part in ill health, especially hole in the head. I think you'll find more people keep their fish in poor conditions than people who feed unsuitable food. I would say that the majority of people who start keeping fish for the first time don't understand the biological side of keeping fish. It all goes back to when you used to win goldfish at fairs, you would bring them home, plonk them in a bowl of water and then a couple of weeks later, the fish would be dead.

As for charcoal, if you look at it logically, charcoal is used to remove impurities from the water. Once it has become saturated, it will start leeching back into the water if it is not replaced. That can't be good for your tank. Personally, I don't use it, I just do a very large water change a couple of days after medicating the tank. Luckily, I haven't had to medicate my tank much at all. This is why I always think a hospital tank is a good idea.