The Effect of Antimalarials Over Time for People with Lupus
- Systemic lupus erythematosus in the elderly: Antimalarials in disease remission
Rheumatology International, Published Online April 8, 2009
What is the topic?
There is some evidence that when people with lupus get older—into their 60s and later— lupus disease activity may lessen, with fewer flares and milder symptoms, or even disappear. This may be because the immune system usually slows down as people age, so autoimmune disease activity could also decrease. Some studies have shown that individuals who develop lupus late in life have more moderate disease than people who develop lupus when they are young. Like other lupus patients whose lupus disease is less active, older patients may continue to take antimalarial medicine to treat or prevent flares.
Antimalarial medicines -- chloroquine (trade name, Aralen®); hydroxychloroquine (trade name, Plaquenil®); and quinacrine (trade name, Atabrine®) -- have been used to treat lupus for many years, especially skin or joint involvement.
Side effects from antimalarials are relatively rare and usually mild; they include upset stomach and, with quinacrine in particular, reversible changes in skin color. Over time, with high accumulating doses, chloroquine or hydroxychloroquine may damage the retina of the eye, potentially causing serious vision problems if not carefully monitored. However, even with the long-term use of hydroxychloroquine (which is used more often in the United States than chloroquine, the risk of this complication is extremely low.
What did the researcher hope to learn?
The researcher wanted to find out why and how frequently elderly lupus patients might be told to stop taking antimalarial medications, and what impact this might have on their lupus disease activity.
Who was studied?
The study had 57 lupus patients, all age 65 or older, who were seen consecutively between 2002 and 2008 at the Rheumatology Division at University of São Paulo (Brazil) School of Medicine. Fifty-three of the 57 patients were women, and half were Caucasian. The Rheumatology Division usually starts all of its lupus patients on chloroquine, so all of the patients were either using chloroquine or had used it in the past.
How was the study conducted?
The 57 patients in the study were divided into two groups: those whose disease was inactive (43 patients, 75.3%) at the time of the analysis; and those whose disease was active (14 patients, 24.6%). The active disease group was made up of patients who were taking steroids (5-20 mg/day) and/or immunosuppressant medications (thalidomide 50-100mg/day, azathioprine 1.5-2.0 mg/kg/day, or methotrexate 10-20 mg/week). The researcher looked at the records collected at the time of each patient’s visit, comparing the chloroquine use in the two groups, as well as the health status of each person, especially any lupus-related conditions they reported.
What did the researcher find?
The researcher found that doctors had stopped choloroquine for 21 of the 57 patients (36.8%)—one patient who developed leucopenia (a drop in the number of white blood cells, which could be a risk for infection), one patient who developed myasthenia gravis (an autoimmune disease that results in muscle weakness), and 19 patients who developed eye disease. On average, patients on chloroquine had been taking the medicine for at least 10 years; those who were no longer taking chloroquine had stopped for five years, on average.
Among the two study groups, 33 of the 43 patients in the inactive disease group (76.7%) were using chloroquine, compared to three of the 14 patients with active disease (21.4%). This suggested the possibility that the inactive status of the disease was significantly associated with continued antimalarial use.
As a whole, the researcher characterized the elderly patients’ lupus as relatively mild, for both those whose disease was inactive and those with active disease. He based this, in part, on the most commonly reported symptoms for the previous years of their disease. Also, the active disease symptoms were mainly flares of skin or joint involvement, rather than more serious organ involvement.
The two groups (inactive vs. active disease) were similar in terms of average age (69.8 years old vs. 67.8 years old), gender (93% women vs. 92.9% women), and average age at disease onset (46.9 years vs 42.3 years).
What were the limitations of the study?
The antimalarial drug at the center of this research was chloroquine. However, the antimalarial hydroxychloroquine is much more commonly used with lupus patients in the United States, and it is much less likely to cause eye problems than chloroquine. Since chloroquine-related eye disease was the reason that the majority of the patients in this study were taken off their antimalarial medication, this could affect treatment decisions about continuing chloroquine in elderly lupus patients who have not developed eye problems.
The number of patients in this study was small, especially the group with active lupus disease, which had only 14 patients. A small study group size can also affect the findings.
Finally, although the study found a significant association between the use of antimalarial medication and inactive lupus disease, an association does not necessarily indicate a cause-and-effect relationship. The study did not report specific information about lupus activity in the patients, so it is not possible to know if, in the years before the study was done, the patients in the disease activity group might have had more serious disease than the patients in the inactive disease group.
What do the results mean for you?
This study supports other research which has shown that elderly people with lupus often have relatively mild disease. It also suggests the possibility that an antimalarial such as chloroquine may keep the disease in check, confirming previous reports that antimalarials may prevent lupus flares.