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. Plaquenil nightmares Chloroquine aralen should be administered how Chloroquine is used to prevent or treat malaria caused by mosquito bites in countries where malaria is common. Malaria parasites can enter the body through these mosquito bites, and then live in body tissues such as red blood cells or the liver. Side effects include irritability, headache, weakness, hair lightening or loss, stomach upset, nausea, dizziness, muscle pain, rash and itching. Rarely, hydroxychloroquine can affect the bone marrow leading to reduced white blood cells leukopenia or platelets thrombocytopenia and abnormal red blood cells anemia. For all uses of chloroquine Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered. Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain. Signs of low blood sugar like dizziness, headache, feeling sleepy, feeling weak. 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. Chloroquine headache Hydroxychloroquine MedlinePlus Drug Information, Hydroxychloroquine Plaquenil Side Effects & Dosage for Malaria Plaquenil kopenWhat stage of infection did the chloroquine treat Headache hearing loss inability to move the eyes increased blinking or spasms of the eyelid joint or muscle pain large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs light-colored stools loss of balance control lower back or side pain muscle trembling, jerking, or stiffness Chloroquine Oral Route Side Effects - Mayo Clinic. Chloroquine Indications, Side Effects, Warnings -. Chloroquine toxicity and Headache - Symptom Checker - check.. 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 lupus, rheumatoid arthritis, and others. Malaria is spread by mosquitoes. Hydroxychloroquine is a well-tolerated medication for various rheumatologic and dermatologic conditions. Its main side effects are gastrointestinal upset, skin rash, headache, and ocular toxicity1. Within the eye, hydroxychloroquine can adversely impact the cornea, ciliary body, and retina1 Adverse effects Seizures. Deafness or tinnitus. Nausea, vomiting, diarrhea, abdominal cramps, and anorexia. Mild and transient headache. Skin itchiness, skin color changes, hair loss, and skin rashes. Unpleasant metallic taste. Chloroquine retinopathy. Hypotension and electrocardiographic.