Effects - Health Effects of Unaffected Users?

[room21]

*Personal Disclaimer: This posting is purely hypothetical and in no way admits or encourages illegal actions or the use of illegal substances. It is wholly educational/informational in nature and does not imply knowledge of unlawful actions by others, this poster assuming all other posts being also hypothetical.

Background:
I used the search function but didn't find exactly what I was looking for. I know a goldfish, we'll call him Bob, who is not affected by cocaine the way other goldfish are. Bob is a fairly new user who was given some by one of his goldfish friends, Fred, who is also affected differently than average. They shared a small bag (Bob does not know what it is called, but he would guess it would fit half maybe half a teaspoon.) and it has lasted about 2 weeks at the most, at which point it began to show signs of deterioration and was finished rather quickly to prevent loss of potency. Despite Fred being the more experienced of the two, he kindly gave most of the substance to Bob, taking no more than a quarter of the bag himself. They both experience a relaxed feeling, as opposed to the normal "high" feeling others mention. Neither get chatty, hyper, paranoid, or moody. They instead feel only slightly energized for a few minutes after taking, with a sense of calm and happiness being the main effect. Fred does get the loss of appetite but Bob has no trouble feeling hungry and eating. I would hesitate to ascribe the reactions to ADD, since Bob has ADD but Fred does not and yet the effects are the same for the most part. Bob also has a much faster metabolism than Fred, so I am uncertain if that would play any role in it.

Question:
Out of curiosity, I did a bit of research into the medical consequences of cocaine usage. Most of the harm seemed to be a result of addiction. The real physical harm seemed (in my limited medical knowledge) to only be a concern if one is affected like the average goldfish, and I never found anything about goldfish who have opposite reactions. Things like irregular heartbeat, heart attacks, etc. would be a risk if it caused the increased pulse and heartbeat. However, are these still a concern if it does not cause increased pulse or heart rate? If one's goldfish is instead calmed by it, should they fear health concerns the same as others, are there a different set of risks, or are they safe? Obviously, there is still the damage to the nasal tissue, but this is a fairly minor concern. I apologize if this sounds like a stupid inquiry, but I was curious. Also if more information is needed to answer, then just let me know and I will ask Bob.