It's safe in a controlled environment, when you use medication in your aquarium you need to control the parameters and use these methods:

- Change 40 % of the tank's water volume, once a week.
- Put activated carbon in the filter for remove the medication surplus from the water.

**BUT FIRST** try to don't use medications, look for alternative methods, for example:

- Termoteraphy
- Aloe vera
- Alimentation change (green peas)