Turns the AAO limit of 5.0 mg/kg/day into a weekly tablet schedule and shows when retinal screening is due, using the 2025 AAO recommendations.
This page does arithmetic and scheduling from a published guideline for prescribers and eye care teams. It does not choose a dose or replace examination. Read these limitations before relying on a result.
Source: AAO 2025 recommendations (reference 1). Interpretations made by AutoimmuneCalc carry no reference number.
How to use it. Part 1 turns a body weight into a weekly tablet schedule at or under the limit. Part 2 shows when eye screening is due. Each part works on its own, and the date logic uses today’s date.
Hydroxychloroquine is widely used in lupus, rheumatoid arthritis, and related conditions. Its main serious risk is retinal toxicity, which is generally not reversible, may continue to progress after the drug is stopped once it is severe, and often causes no symptoms until late[1].
The risk depends on the daily dose per kilogram of real weight and on how long the drug is taken. At 5.0 mg/kg/day or less, the report cites a likelihood of toxicity below 1% within 5 years and below 2% even after 10 years, rising much faster as the dose nears 6.0 mg/kg[1]. Screening aims to find early changes while there are still options[1].
| Step | Rule |
|---|---|
| Limit | Weight in kg times the target mg/kg/day (never above 5.0) times 7 gives the most that can be taken in a week. With severe obesity the weekly limit is also capped at 2,800 mg (400 mg/day).[1] |
| Steps | The weekly total is the largest multiple of 200 mg (whole tablets) or 100 mg (half tablets) that does not exceed the limit. It is never rounded up. |
| Spreading | The total is divided over 7 days so that no day differs from another by more than one step, with the larger days spaced apart. The calendar starts on Monday only for display; rotate it to suit the patient. |
| Topic | Recommendation |
|---|---|
| Baseline | A full examination, including fundus examination, OCT, and wide-pattern autofluorescence, close to the start of therapy.[1] |
| Annual screening | Yearly with OCT and wide-pattern autofluorescence. May be deferred for the first 5 years if there are no significant risk factors, provided it starts reliably after 5 years. With significant risk factors, begin at initiation.[1] |
| Primary tests | OCT and wide-pattern autofluorescence. Visual fields and multifocal electroretinography are secondary. Fundus examination alone, Amsler grid, and color testing are not recommended for annual screening.[1] |
| Patterns | Patients of European heritage most often show parafoveal toxicity and East Asian patients pericentral toxicity, with many exceptions, so screening should look for both. Scans should extend beyond the arcades, ideally to 50 or 55 degrees.[1] |
| Each visit | Check the dose against current weight and ask about kidney disease, tamoxifen use, and major weight loss.[1] |
The American Academy of Ophthalmology (AAO) recommends a daily dose of 5.0 mg/kg or less of real body weight. The report says doses near 6.0 mg/kg markedly accelerate the risk of retinopathy. Severely obese patients should start with a lower calculated dose and a maximum of 400 mg/day, which can be raised for medical need with careful monitoring.
The AAO states its limit in terms of real (actual) body weight. A calculation based on a lower ideal weight would give a lower dose, so use the measured weight and re-check it at each visit, because major weight loss changes the dose per kilogram.
The report says intermediate doses can be made by splitting tablets or omitting a tablet on certain days, and that variable dosing averages out because blood levels stabilize over many weeks. This calculator finds the largest weekly total in 200 mg steps (or 100 mg steps with half tablets) that stays at or under your limit, and spreads it across the week.
The AAO advises a baseline screening examination soon after hydroxychloroquine is started, including a fundus examination, OCT, and wide-pattern fundus autofluorescence. It rules out existing eye disease and gives a reference for later comparison.
Annual screening with OCT and wide-pattern autofluorescence is recommended while using the drug. It may be deferred during the first 5 years if there are no significant risk factors, as long as screening reliably starts after 5 years. With significant risk factors, annual screening should begin at initiation.
From Table 1 of the report: a daily dose above 5.0 mg/kg (or above 400 mg/day in severe obesity), use for more than 5 years, renal disease (reduced glomerular filtration), tamoxifen, macular disease that affects vision or the ability to screen, and starting hydroxychloroquine at an older age.
OCT and wide-pattern autofluorescence are the primary tests. Visual fields and multifocal electroretinography are secondary or confirmatory. The report lists fundus examination alone, OCT angiography, Amsler grid, color testing, and others as not recommended for annual screening. Because patients of East Asian heritage often show pericentral toxicity and others parafoveal, screening should look for both patterns.
The dose limit is unchanged. The 2025 revision adds older age at initiation as a risk factor, names OCT with wide-pattern autofluorescence as the primary screening tools, advises that the baseline examination include them, and sets a 400 mg/day maximum for severely obese patients. The 2016 version called for a baseline fundus examination and annual screening after 5 years.
No. It shows the highest schedule that stays within the AAO limit, plus lower steps. The right dose is the lowest one that controls the disease, and it is chosen by the prescriber.
The limit, the severe-obesity maximum, the tablet-splitting guidance, the risk factors, and the screening rules were taken from the 2025 AAO report. The schedule calculation was tested against a separate exact calculation for every weight from 30.0 to 300.0 kg, and the screening dates were tested against a separate implementation. Every place where we interpret the report is stated under the limitations.
Page history. October 15, 2026: page published.