Some people have symptoms like these for the first week or two of taking Plaquenil, but generally it goes away after that. You might try taking it before, after or with meals to determine what works best for you. Some people find it works better on an empty stomach, some have better luck with a full stomach.
Plaquenil is supposed to inhibit the progression
of the disease, so you can't really tell if it's actually doing that or not!! (That is, would your illness have gotten worse without the Plaquenil? Maybe it wouldn't have!) People have reported that when they have gone off of it, that their symptoms have gotten worse, which indicates that it probably was helping them.
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2000DIAGNOSING LUPUS & HW's LUPUS 101
"Life is far too important to be taken seriously." - Oscar Wilde