A new case of cutaneous lupus erythematosus (CLE) or systemic lupus erythematosus (SLE) could potentially be drug induced as a significant number of associations were observed between a variety of medications and a subsequent diagnosis of these conditions, according to the findings of a recently published matched case-control study.

The nationwide study aimed to determine the association between medication use and a subsequent diagnosis of either CLE or SLE. The Anatomical Therapeutic Chemical classification system was systematically screened to determine which drugs would be examined in the study. All incident cases of CLE and SLE that were registered between January 1, 2000, and December, 31, 2017, in the Danish National Patient Register were included in the analysis. “Patients with CLE and patients with SLE were matched (1:10) on age and sex, with individuals from the general population serving as controls,” the study authors explained.

The baseline characteristics of the control group (n=31,480) were well matched to the CLE or SLE group (n=3148). The study authors reported that, although a significant number of associations between medication use and a subsequent diagnosis of CLE or SLE were observed, many could likely be attributed to protopathic bias.

Despite this, new plausible casual associations between CLE or SLE and some medications were observed. The odds ratios (ORs) for these casual associations were reported to be 2.61 (95% CI, 1.80-3.80) for SLE and 5.05 (95% CI, 3.51-7.26) for CLE for fexofenadine hydrochloride, 2.46 (95% CI, 1.97-3.07) for SLE and 1.30 (95% CI, 0.96-1.75) for CLE for levothyroxine sodium, 3.38 (95% CI, 2.47-4.64) for SLE and 1.47 (95% CI, 0.85-2.54) for CLE for metoclopramide hydrochloride, and 1.57 (95% CI, 1.09-2.27) for SLE and 1.93 (95% CI, 1.25-2.97) for CLE for metronidazole hydrochloride.

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“To our knowledge, these drugs have not been previously reported as inducing [drug-induced lupus erythematosus], and protopathic bias is less likely,” the study authors concluded, adding that “hypothyroidism is reported in 4% of patients with SLE, which could partially explain the association between levothyroxine sodium and SLE.”

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.

Reference

Haugaard JH, Kofoed K, Gislason G, Dreyer L, Egeberg A. Association between drug use and subsequent diagnosis of lupus erythematosus [published online September 2, 2020]. JAMA Dermatol. 2020; doi: 10.1001/jamadermatol.2020.2786.