Malaria is common in areas such as Africa, South America, and Southern Asia. This medicine is not effective against all strains of malaria. When should you take hydroxychloroquine What happens if you take too much hydroxychloroquine Hydroxychloroquine generally is given to adults in doses of 200 mg or 400 mg per day. In some cases, higher doses can be used. Your doctor may gradually increase or decrease your dosage over time to find the right levels for your specific symptoms and needs while having the least amount of negative side effects. For long-term use, the dose of hydroxychloroquine is usually reduced to 200 mg to 400 mg daily. Malaria The recommended preventative adult dose is 400 mg on exactly the same day of each week, beginning 2 weeks before exposure and continued for 8 weeks after leaving the high-risk area. The usual starting dose of Plaquenil is 200 mg twice a day or 400 mg once a day, administered orally, in people weighing 80 kg or more. The usual dosage works for most people who take Plaquenil, but it is possible to increase or decrease the dose based on individual needs. It's important to watch for possible side effects and toxicity. Taking hydroxychloroquine long-term or at high doses may cause irreversible damage to the retina of your eye. Hydroxychloroquine is also an antirheumatic medicine and is used to treat symptoms of rheumatoid arthritis and discoid or systemic lupus erythematosus. Side effects of plaquenil 400 mg Plaquenil Hydroxychloroquine Uses, Dosage, Side Effects., Plaquenil - Uses, Side Effects, Interactions - Chloroquine mechanism of action lupusCan i take a multivitamin with plaquenil Find patient medical information for Hydroxychloroquine Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Hydroxychloroquine Oral Uses, Side Effects, Interactions.. Taking Plaquenil for Rheumatoid Arthritis. Hydroxychloroquine Side Effects Common, Severe, Long Term.. Common hydroxychloroquine side effects may include headache, dizziness, ringing in your ears; nausea, vomiting, stomach pain; loss of appetite, weight loss; mood changes, feeling nervous or irritable; skin rash or itching; or. hair loss. For treating lupus in adults, the recommended starting Plaquenil dosage is 400 mg once or twice a day. After a while, your healthcare provider may recommend a lower dosage such as 200 mg once daily. The higher the long-term dosage, the more likely that serious Plaquenil side effects especially eye damage may occur. Mg 310 mg base to 600 mg 465 mg base PO daily, administered as a single daily dose or in 2 divided doses. Do not exceed 600 mg/day 465 mg base/day or 6.5 mg/kg/day 5 mg base/kg/day, whichever is lower. Side effects may require a temporary initial dose reduction.