That left Plaquenil. In the treatment of SLE, it’s widely regarded as a cornerstone drug in the management of skin and arthritis symptoms.
In RA, Plaquenil is prescribed as monotherapy in mild disease or combined with other disease-modifying medications to control more aggressive disease.
Plaquenil is included in the World Health Organization’s List of Essential Medicines, a listing of the essential medications needed in a basic health system.8 The drug, in its generic form, is cheap and generally well tolerated. It does not require regular laboratory monitoring. It can be continued in patients receiving antibiotics for bacterial infections. Although it is considered to be a category C drug, it is generally regarded as safe for women to continue on during pregnancy, and lactating women may breastfeed while taking the drug.9
The Research Says …
Like the Cinchona tree, Plaquenil has a number of additional valuable and surprising properties.
The beneficial effects of Plaquenil on lipid profiles have been confirmed in numerous trials.10-12 These effects are relatively small, with decreased LDL and triglycerides, but in RA and SLE, any medication that can partially mitigate the unfavorable lipid profiles of patients often on corticosteroids is not insignificant.
In 1990, the Annals of Internal Medicine published an intriguing article by Antonio Quatraro, MD, “Hydroxychloroquine in Decompensated, Treatment-Refractory Noninsulin-Dependent Diabetes Mellitus: A New Job for an Old Drug?”13 This small, prospective, randomized, placebo-controlled trial found clinically meaningful improvement in glucose control with Plaquenil.
Other studies followed. Mary Chester M. Wasko, MD, at the University of Pittsburgh, determined in a large prospective trial of 4,905 adult RA patients that long-term use of Plaquenil reduced the risk of diabetes mellitus.14 Risk reduction was both dose and duration dependent; RA patients taking 400 mg Plaquenil daily for more than than four years had a 77% lower risk of developing diabetes than RA patients who never received the drug.
Lastly, Rekedal and colleagues found significant reductions in glycosylated hemoglobin in established diabetic patients with rheumatic disease after initiation of Plaquenil compared with methotrexate.15 The mean change in HbA1c of 0.66 from baseline was only slightly less than with frequently prescribed oral hypoglycemics.15
For patients at risk of thrombosis, Plaquenil may lower this risk. Michelle Petri, MD, found that in her cohort of 2,000 SLE patients at Johns Hopkins, those with phospholipid/lupus anticoagulants on long-term Plaquenil had a lower risk of thrombosis than those who never took the drug.16 Studies in the early 1970s explored the antithrombotic effects of Plaquenil in patients undergoing hip arthroplasty.17 Although most studies demonstrated moderate efficacy in preventing postoperative deep venous thrombosis, newer regimens with heparin and warfarin have proved superior.
Additional Potential Uses
A number of additional disorders exist for which a trial of Plaquenil is more than reasonable. Dermatologists use the drug for polymorphous light eruptions, granuloma annulare, porphyria cutanea tarda and necrobiosis lipoidica diabeticorum. Rheumatologists are often pleasantly surprised at follow-up that their patient’s undifferentiated connective tissue disorder (UCTD), palindromic rheumatism or inflammatory osteoarthritis has improved. A subset of hypocomplementemic urticarial vasculitis may respond to Plaquenil. Current EULAR recommendations suggest that Plaquenil be considered as an adjunctive treatment in chronic (but not acute) calcium pyrophosphate deposition (CPPD) arthropathy.18