Although not all of these side effects may occur, if they do occur they may need medical attention. Check with your doctor immediately if any of the following side effects occur while taking hydroxychloroquine: Incidence not known Some side effects of hydroxychloroquine may occur that usually do not need medical attention. Chloroquine atovaquone Complete list of side effects of plaquenil What does a plaquenil rash look like Hydroxychloroquine sulfate is a colorless crystalline solid, soluble in water to at least 20 percent; chemically the drug is 2-4-7-Chloro-4-quinolylaminopentylethylamino ethanol sulfate 11. PLAQUENIL hydroxychloroquine sulfate tablets contain 200 mg hydroxychloroquine sulfate, equivalent to 155 mg base, and are for oral administration. Nausea and diarrhea This can often can be combatted by taking Plaquenil with food or milk. If you experience stomach upset while taking generic hydroxychloroquine, ask your doctor about trying name-brand Plaquenil instead. Hydroxychloroquine typically is very well tolerated. Serious side effects are rare. The most common side effects are nausea and diarrhea, which often improve with time. Less common side effects include rash, changes in skin pigment such as darkening or dark spots, hair changes, and muscle weakness. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. These side effects may go away during treatment as your body adjusts to the medicine. Plaquenil for diarrhea Medicines for the Prevention of Malaria While Traveling., Plaquenil What You Need to Know - Kaleidoscope Fighting Lupus Chloroquine and anxietyPlaquenil photosensitivity rash Many people have nausea, stomach cramps, and diarrhea when they first start taking Plaquenil hydroxychloroquine. If you have heart, eye, liver conditions, or psoriasis, talk to your doctor to see if Plaquenil hydroxychloroquine is right for you. Compare Plaquenil vs Chloroquine -. Hydroxychloroquine Plaquenil. Plaquenil Uses, Dosage & Side Effects -. Plaquenil is the brand name for the prescription drug hydroxychloroquine. It's used to treat and prevent malaria infection, and to reduce symptoms and progression of autoimmune diseases such as. I've been on Plaquenil for almost 2 wks now and I'm also taking Prednisone, could one of these be causing my extreme stomach cramps? 2 nights ago, I had a cheeseburger and mac and cheese and I thought I was going to die about 1 in the morning. I ended up throwing up once and then I had diarrhea for a bit and then it passed once my system cleared. I suspect plaquenil for giving me some episodic diarrhea. I am 100 mg dose and take it with my supper. Did they happen to anyone else and did it eventually stop with the diarrhea side effect? It helps so much with the fatigue and pain. I have a sensitive stomach and perhaps I shouldn't have eaten that salad for lunch yesterday.