What is the typical dosage of Hydroxychloroquine (HCQ) for adults with conditions like lupus or rheumatoid arthritis?

Hydroxychloroquine 200 MG Oral Tablet Dosage

For adults with lupus or rheumatoid arthritis, hydroxychloroquine should be dosed at ≤5 mg/kg actual body weight per day, which typically translates to 200-400 mg daily, with the specific dose calculated based on the patient's actual weight to minimize retinal toxicity risk. 1

Standard Dosing Regimens

Systemic Lupus Erythematosus (SLE)

• Starting dose: 200 mg once daily or 400 mg once daily (can be divided into two doses) 1, 2
• The maximum safe dose is ≤5 mg/kg actual body weight per day to keep retinopathy risk below 2% over 10 years 1
• Hydroxychloroquine is recommended for all patients with SLE due to reduced flares, organ damage prevention, and improved survival 1, 3

Rheumatoid Arthritis (RA)

• Initial dosage: 400-600 mg daily as a single dose or two divided doses 2
• Chronic maintenance: 200 mg once daily to 400 mg daily 2
• The action is cumulative and may require weeks to months for maximum therapeutic effect 2

Chronic Discoid Lupus Erythematosus

• 200 mg once daily or 400 mg once daily (can be divided into two doses) 2

Critical Dosing Calculations

Use actual body weight, not ideal body weight, for dose calculations 1. The evidence demonstrates that retinopathy risks were statistically similar across BMI groups (15-35 kg/m²) when actual body weight was used 1. This represents a shift from older recommendations that suggested using ideal body weight 4.

Practical Example:

• For a 70 kg patient: Maximum daily dose = 70 kg × 5 mg/kg = 350 mg/day
• This patient should receive 200 mg daily (well within safe limits) or 400 mg daily (at upper safe limit)

Dose Adjustments for Renal Impairment

Reduce the hydroxychloroquine dose by 25% when eGFR <30 ml/min per 1.73 m² 1, 5. Reduced renal function is the greatest additional risk factor for retinopathy, and failing to adjust for renal impairment is the greatest modifiable risk factor for toxicity 1.

Pre-Treatment Requirements

Before initiating therapy, obtain:

• G6PD testing in men of African, Asian, or Middle Eastern origin (hemolysis risk) 1, 5, 3
• Baseline ECG (QT prolongation risk) 1, 5
• Baseline ophthalmologic examination within the first few months 1, 5
• Baseline renal function (eGFR) 3

Ophthalmologic Monitoring Schedule

• Low-risk patients: Annual screening beginning after 5 years of therapy 1, 5, 2
• High-risk patients: Annual screening beginning after 1 year 1, 5

High-risk factors include:

• Daily dose >5 mg/kg actual body weight 1
• Chronic kidney disease (eGFR <60 ml/min per 1.73 m²) 1
• Concomitant tamoxifen use 1
• Pre-existing retinal or macular disease 1

East Asian patients require screening beyond the central macula due to a different retinopathy phenotype involving the pericentral vascular arcade 1.

Administration Instructions

• Take with food or milk 2
• Do not crush or divide tablets 2
• If gastrointestinal side effects occur, the daily dose can be divided into twice-daily administration 3

Common Pitfalls to Avoid

Do not use lower doses (2-3 mg/kg/day) thinking they are safer - these may not achieve adequate blood levels and are associated with higher flare rates in lupus nephritis 1. The goal is to safely maintain hydroxychloroquine as long as possible, not to discontinue it casually 1.

Do not exceed 5 mg/kg/day based on actual body weight - daily doses exceeding this limit significantly increase the incidence of retinopathy 1, 2. In clinical practice, 22.8% of patients were found to be receiving doses greater than 5 mg/kg/day, highlighting the need for vigilant weight-based dosing 6.

Do not forget to adjust for renal impairment - this is the most critical modifiable risk factor 1.