Plaquenil toxicity and lowering dosage

Plaquenil (generic name hydroxychloroquine) is one of the few medications that is regularly prescribed for Sjogren’s Syndrome, despite the fact that it has not been approved for SS by the FDA, so any use is off-label. While clinical trials for it’s effectiveness have been mixed, there are a number of anecdotal reports that describe minor to significant improvements in symptoms. Because there is no approved medication for the systematic manifestations of SS, and because Plaquenil is regarded as generally safe, many doctors prescribe 200-400mg per day to SS patients. I myself have been on Plaquenil for over a year, at 400mg / day.

While Plaquenil can cause a variety of symptoms, most of them are minor and temporary. The most serious symptom, however, is neither minor nor temporary. Permanent, vision-altering retinal damage has been documented in some long-time users of Plaquenil, but it has been regarded as rare, as long as patients use doses appropriate to their mass. My own rheumatologist (whom I highly respect), told me that vision damage from retinal toxicity was a “1 in 10,000” chance. Still, it was known that Plaquenil continues to accumulate over the years, so long-term usage does raise the risk of eye damage.

Unfortunately, a study released earlier this year has demonstrated that the problem is much more prevalent than commonly believed:

The retrospective, case-control study included 2,361 Kaiser Permanente patients who used the drug continuously for at least 5 years.

Evaluation by visual field testing and/or spectral domain optical coherence tomography (OCT) showed the overall prevalence of retinal thinning and photoreceptor damage or visual field loss was 7.5%. The risk climbed with greater daily dosage and duration of therapy, reaching a prevalence of nearly 20% after 20 years on hydroxychloroquine.

The study notes that, using correct dosing, the risks are still low, but 20% is a much higher risk than 1 in 10,000. Barring a cure being developed in the next 20 years, I could potentially find myself as part of that statistic.

During my last meeting with my rheumatologist, he recommended trying a lower dose to see if it impacted my system. A lower dose would certainly mean less risk of eye problems in the future, and I’m not even sure how much benefit I’m getting from it. I’m fairly confident that it has helped reduce my joint pain to low levels, but Plaquenil is so slow-acting that it’s hard for me to know exactly what the effects are. As a result, I decided to try cutting my daily dose from 400 mg to 200 mg.

I was fine for the first several days, but by the end of the week I found myself in a flare. I returned to the 400 mg dose, and the flare passed a few days later. Of course, it’s hard to tell exactly what causes any given flare, but the timing seemed convenient for it being caused by my dose adjustment. Still, I am very wary of eye damage, so I decided to try again, but at 300 mg this time. I have been doing this for the past 2 weeks, and I haven’t noticed any major flares, though I’ve certainly had some fluctuations in my symptoms. If things seem stable after a couple more months, I may try for 200 mg again, with eventual hope that the helminthic therapy, or another future treatment, will allow me to discontinue the Plaquenil before I reach dangerous levels of accumulation.

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