You should talk with your healthcare provider prior to taking this medication if you have:
- Liver disease, such as liver failure, cirrhosis, or hepatitis
- G-6-PD (glucose-6-phosphate dehydrogenase) deficiency
- Any other allergies, including allergies to food, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant (see Plaquenil and Pregnancy)
- Breastfeeding (see Plaquenil and Breastfeeding).
Make sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click Precautions and Warnings With Hydroxychloroquine to learn more, including information on who should not take hydroxychloroquine.)
Hydroxychloroquine works to prevent and treat malaria by entering red blood cells (which are infected by the malaria bacteria), entering the bacteria, and interfering with the internal functions of the bacteria. It probably works for lupus and rheumatoid arthritis by limiting the immune system reactions that cause these diseases.