If a drug is small enough and dissolves in water, it can be carried across with water in aquaponics. Most drugs will move through diffusion, and most drugs will be lipophilic through that process. But even the larger molecular weight ones won't be thrown through with a pump. The active transport drugs are interesting, because it means they need to go against a concentration gradient. This is when you need to start thinking about drugs that resemble a natural physiological metabolite already present in our body.