Hydroxychloroquine Safety Check
Evaluate daily dosing relative to American Academy of Ophthalmology (AAO) guidance to minimize risk of retinal toxicity.
Use Devine or Robinson formula. If unknown, IBW approximates healthy weight for height.
Common doses: 200 mg once or twice daily.
Dose Assessment
Daily dose per kg
6.15 mg/kg actual • 6.67 mg/kg ideal
Safety threshold: ≤5 mg/kg using lesser of actual or ideal weight (currently 6.67 mg/kg).
Safe daily limit
300 mg/day
Current dose: 400 mg/day. Dose exceeds recommended threshold—consider reduction.
Cumulative exposure
1-year cumulative dose: 146000 mg • 5-year exposure: 730000 mg. Monitor annually after 5 years or earlier if high dose, renal disease, or tamoxifen use.
How to Use This Calculator
Determine ideal body weight
Use Devine formula: 45.5 kg + 2.3 kg/inch (female) or 50 kg + 2.3 kg/inch (male) above 5 ft.
Enter actual weight and dose
Calculator compares both actual and ideal weights to enforce ≤5 mg/kg guideline.
Review safety output
If dose exceeds threshold, discuss reduction with rheumatology to prevent retinal toxicity.
Formula
Safety limit: ≤5 mg/kg/day (using lower of actual or ideal weight).
Based on 2016 American Academy of Ophthalmology hydroxychloroquine screening recommendations.
Frequently Asked Questions
Why use ideal body weight?
In obesity, using actual weight overestimates safe doses and increases retinal toxicity risk.
When does screening start?
Baseline exam within 1 year; annual screening after 5 years or earlier if dose >5 mg/kg, renal disease, or tamoxifen use.
What if renal function declines?
Reduce daily dose proportionally; many rheumatologists lower to 200 mg/day when eGFR <60 mL/min.
Is cumulative dose important?
Yes—risk increases after 5–7 years or total dose >1000 g. Monitor closely at higher exposures.
Can I split tablets?
Yes. 200 mg tablets can be halved to achieve 300 mg/day regimens if necessary.