I was on chloroquine for a few years back when I was first diagnosed with lupus back in the mid 90's. It is a very large white pill and VERY bitter. Unfortunately (at least back then) you can't get any enteric coating on it so it is hard to get down and when it gets stuck in your throat, the taste stays with you for a very long time
It does however have the same healing properties of plaquenil which generically is called hydroxychloroquine - the same base drug. At least for me, I felt the same on the chloroquine as I did on the plaquenil although neither medication or any other has ever allowed me a remission from my lupus symptoms. I was told by my rheumie that chloroquine could cause more eye problems than plaquenil which was one of the reasons I made the switch. I think I also remember that it was alot cheaper than plaquenil... Anyway, I hope this little bit of information helps you somewhat!