ORLANDO – Dermatologists should not give up on antimalarials if hydroxychloroquine does not work for a patient with cutaneous lupus erythematosus, according to Anthony Fernandez, MD, PhD, director of medical and inpatient dermatology at the Cleveland Clinic.

A switch to chloroquine, or adding quinacrine, might do the trick, saving at least some patients from having to move on to immunosuppressive therapy, Dr. Fernandez said at the International Conference on Cutaneous Lupus Erythematosus.

A recent study of 64 patients with cutaneous lupus found that about half of those who did not respond to hydroxychloroquine responded to chloroquine, and visa versa, at least for a while. Likewise, more than two-thirds of those who did not tolerate one agent tolerated another (J Am Acad Dermatol. 2018 Jan;78[1]:107-114.e1).

“What we are learning from the literature is that we can switch from one antimalarial to another. We need to think about this in our algorithms before reaching for potentially more toxic immunosuppressives,” Dr. Fernandez said.

As for quinacrine, about two-thirds of patients who fail hydroxychloroquine or chloroquine will have a positive response to quinacrine if added (Br J Dermatol. 2017 Jul;177[1]:188-96). “It’s important to remember that we are not adding any ocular toxicity” with quinacrine, he said.

Quinacrine does come with a major concern of its own: the risk of aplastic anemia. However, this seems to occur with doses higher than 100 mg/day, which are no longer recommended; there have been no reports of aplastic anemia in patients on 100 mg/day or less.

Quinacrine “is an underutilized antimalarial. I think a lot of people don’t know about it or know how to get it. It can be compounded into capsules for patients,” and for a reasonable price, at about $20 for a month supply at some pharmacies, Dr. Fernandez said.

Meanwhile, because of the risk of retinal toxicity with hydroxychloroquine, there’s been a shift in recent years from dosing up to 6.5 mg/kg per day of ideal body weight to a ceiling of 5 mg/kg per day of actual body weight (JAMA Ophthalmol. 2014 Dec;132[12]:1453-60), and a ceiling of 2.3 mg/kg per day actual body weight for chloroquine.

The idea was to prevent overdosing in people who are under their ideal body weight, but there have been concerns about the efficacy of the new dosing regimen in other patients. Dr. Fernandez has not seen evidence of this. “We do adhere to the new dosing recommendations” at the Cleveland Clinic, and “personally, I think we are seeing similar efficacy,” he said.

The most important risk factor for retinal toxicity is cumulative dose. The risk seems to be extremely low in the first 5 years, but increases afterwards. Most patients who develop retinal toxicity have taken a cumulative hydroxychloroquine dose of 1,000 g, equal to about 400 mg/d for 7 years. “The longer you are on the medicine, the higher your risk of developing retinal toxicity,” he noted.

Regardless of weight, it’s recommended to limit hydroxychloroquine to 400 mg daily and chloroquine to 250 mg daily, with a baseline ocular exam, and – barring any intervening problems – annual screening after 5 years.

In patients with highly active skin disease at baseline, Dr. Fernandez said he will sometimes start hydroxychloroquine higher than 400 mg initially but will bring patients back down to 400 mg after a few months.

Dr. Fernandez had no relevant disclosures.

aotto@frontlinemedcom.com

Cutaneous lupus: Switching antimalarials can delay immunosuppressive therapy