If the medicines from Neopia Central are too expensive, you can try some of the exotic remedies this Cybunny provides. She also made a very brief appearance in the Hannah and the Ice Cave comics.
The finest cures in the entire Lost Desert!
I hate to do this but I need to ask you, are you from Qasala?
Oh dear! I am meant to turn you down but go ahead and look around anyway. Make sure the guards aren't watching!
Please go ahead and peruse the items here. I am sure you will find your cure.