[fikama]

You got me interested, could you say more about how are doing this? What exactly sounds different to you, and maybe what is your first language too. I am European but my first language is polish so in this context it is useless :P

[jltsiren]

My first language is Finnish, which has a very straightforward correspondence between spelling and pronunciation.

I would divide the drug names into four categories based on how they sound:

Obviously a substance: Amantidine, Sildenafil

Generic fantasy names / pronounceable strings with no meaning: Azafen, Clédial, Cymbalta, Desyrel, Edronax, Luvox

Could be Tolkienian, but it's spelled wrong: Sintamil

Could be Tolkienian, but the final syllable is wrong: Elronon, Eskalith, Nardil

Additionally, the two Tolkien characters I had to guess were both kings of Gondor: Minalcar and Narmacil. Their names are in Quenya, while the commonly used names for elves etc. are in Sindarin, which sounds different.

[User3456335]

It sounds like you got by more on thorough knowledge of Tolkien than your knowledge of Finnish. I'm going to guess there's more speakers of non-English languages here than of Quenya and Sindarin (which may have been pharmaceutical names for all I know).