Hydroxychloroquine Dose Calculator

Using the Hydroxychloroquine Dose Calculator is straightforward:

Step 1: Select the medical condition or indication (e.g., Lupus, Rheumatoid Arthritis, or Malaria).

Step 2: Enter the patient's actual body weight in kilograms. You can also use the slider for a quick adjustment.

Step 3 (Optional): Enter the prescribed or planned daily dose in milligrams if you want to check whether it falls within the safe threshold.

Step 4: Click 'Calculate Safe Dose' to see the maximum recommended daily dose and — if a custom dose was provided — whether it exceeds the FDA/AAO safety limit of 5 mg/kg/day.

The results include the calculation formula, the per-kg rate, and a safety status indicator.

The key formula used is:

Maximum Daily Dose (mg) = Actual Body Weight (kg) × 5 mg/kg

This 5 mg/kg/day threshold is based on guidance from the American Academy of Ophthalmology (AAO) and the FDA, established to minimize the risk of irreversible retinal toxicity (maculopathy) with long-term use.

Example: - Patient weight: 68 kg - Maximum safe dose: 68 × 5 = 340 mg/day

If a prescribed dose of 400 mg/day is entered for the same patient: - Dose per kg: 400 / 68 = 5.88 mg/kg/day - Status: Exceeds the 5 mg/kg/day safety limit — physician review recommended.

Note: Dosing is always based on actual body weight, not ideal body weight, as per updated AAO 2016 guidelines.

The Hydroxychloroquine Dose Calculator is an essential safety tool designed to help patients and healthcare providers quickly verify if a prescribed regimen falls within the recommended safety thresholds. Hydroxychloroquine, frequently recognized by the brand name Plaquenil, is a fundamental medication utilized to manage chronic autoimmune disorders like Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA), along with being prescribed for malaria.

Because this medication can gradually accumulate in the retina over years of continuous use, precise weight-based dosing is absolutely critical. Current medical guidelines state that exceeding 5 mg per kilogram of a patient's actual body weight per day significantly elevates the risk of developing chloroquine retinopathy—a serious condition that can lead to permanent vision damage. Our calculator provides an instant, mathematically accurate assessment based on the latest ophthalmology standards to help avoid this risk.

Please remember that this calculator serves as an informational cross-check and never replaces professional clinical judgment. It uses standard weight-based parameters and does not account for specific individual variations such as liver impairment or kidney disease, which often necessitate independent medical dose adjustments.