Friday, 15 Nov 2019

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5 Things To Know About Antimalarials for Lupus

1. Many patients should take less than 400 mg qd of hydroxychloroquine.

A recent study evaluated the largest patient population ever studied (2,361 patients) for HCQ-associated retinopathy.1 The study found that dosing HCQ at a dose of 5 mg/kg of actual body weight or less proved to be more protective against retinopathy than previously-recommended doses based on ideal body weight. Therefore, patients who weigh between 132 and 175 pounds should only take 300 mg daily of HCQ to decrease their risk of retinopathy. Those who weigh less than 132 pounds or over 175 pounds should take 200 mg daily and 400 mg per day respectively. I implemented this recommendation in my lupus cohort, and most of them have remained in clinical quiescence. Note that this dosing recommendation is based upon the prevention of retinopathy and not upon efficacy. If a patient requires a higher dose, I would recommend obtaining and documenting informed consent from the patient.

2. HCQ retinopathy is NOT rare.

We should stop saying “HCQ retinopathy is rare.” I now have 12 patients in my practice who have HCQ retinopathy. Welles’ study showed close to a 20% prevalence of retinopathy after 20 years of HCQ usage. We began to use HCQ universally in lupus patients in the late 1990s. So we are now just seeing the “tip of the iceberg” because this large group of patients will soon be entering their third decade of HCQ treatment.

3. Mandate a VF 10-2 plus either an SD-OCT, FAF, or mfERG from your ophthalmologists.

HCQ retinopathy can be diagnosed at early, asymptomatic stages if two screening tests are performed yearly. The American Academy of Ophthalmology recommends that a central visual field test 10-2 be performed yearly, along with either a spectral-domain optical coherence tomography (SD-OCT), fundus fluorescence (FAF), or multifocal electroretinography (mfERG) test.2 Performing only one test is not sufficiently sensitive. In my experience, many ophthalmologists do not have the necessary equipment to perform these tests. We should be diligent in ensuring our patients only see ophthalmologists who are able to perform these tests. Do not accept a consult result of “no Plaquenil toxicity.” Contact the ophthalmologist to ensure the proper tests are performed. If they are not performed, send your patient elsewhere. In addition, do not be confused with similar sounding, less sensitive tests such as a VF 24-2 test, which is not adequate.

4. Rheumatologists should prescribe quinacrine more often.

Lupus dermatologists recommend the addition of quinacrine to HCQ as the treatment of choice for HCQ-resistant cutaneous lupus erythematosus (CLE).3 However, I rarely see it used by rheumatologists. Quinacrine is not only effective for the treatment of CLE, but also for lupus arthritis, fatigue, and cytopenias. It can be obtained from compounding pharmacists (for example, Village Green Apothecary in Bethesda, Maryland) and shipped to patients. Daniel Wallace’s papers regarding the use of quinacrine offer excellent, practical advice for its usage.4

5. Use an antimalarial even if patient is on a strong immunosuppressant (improves remission rates).

Michelle Petri, MD and others showed the use of HCQ along with mycophenolate mofetil (MMF) in patients with lupus membranous nephritis achieved remission three times more often than those who were on MMF without HCQ.5 This clearly showed the additive effect of HCQ along with MMF. Since lupus remission (or clinical quiescence) is associated with less permanent organ damage, we should be using HCQ in all of our patients, even if they are taking a strong immunosuppressant such as MMF.

References:
1. Welles RB, Marmor MF. JAMA Ophth. 2014 Dec;132(12):1453-60.
2. 
Marmor MF et al. Ophth. 2011 Feb;118(2):415-22.
3. 
Werth VP. Arthr Res & Ther. 2014 Sep;16(Suppl 1):A5
4. 
Wallace DJ. Lupus. 2000 Feb;9(2):81-2.
5. 
Petri M et al. Lupus. 2006 June;15(6):366-70.

Disclosures: 
The author has no conflicts of interest to disclose related to this subject

Donald Thomas, Jr., MD, FACP, FACR, is anAssistant Professor of Clinical Medicine at the Uniformed Services University of the Health Sciences, Bethesda, Maryland. He is in clinical practice at Arthritis and Pain Associates of PG County in Greenbelt, Maryland and is actively involved in patient care and medical education. He has a special interest in lupus, currently serves as the Chair of the Lupus Foundation of America DC/MD/VA chapter, and is the author of “The Lupus Encyclopedia: A Comprehensive Guide for Patients and Families.”

 

Rheumatologists' Comments

Excellent review. Even though there are precautions to be taken, Plaquenil remains one of the safest drugs we use.