Types of Lupus: Drug-Induced Lupus
Drug Induced Lupus Erythematosus, or DLE, is a side effect that is developed after taking certain kinds of medication over an extended period of time.
Symptoms of DLE
Drug Induced Lupus shares some of its symptoms with SLE, including:
- Muscle and joint pain or swelling
- Fatigue and fever
- Pain or discomfort due to Serositis, an inflammation of the heart or lungs
The medication should be stopped and symptoms will decrease after a few days and disappear after a week.Doctors can then diagnose DLE because the symptoms reversed when the medication was discontinued.
Medications that are used to treat chronic diseases like heart disease, hypertension, and thyroid disease are typically the same drugs that cause DLE.Reportedly at least 38 drugs cause DLE, including:
- procainamide (Pronestyl)
- hydralazine (Apresoline)
- quinidine (Quinaglute)
These three are most linked to Drug Induced Lupus cases, and the remaining 35 drugs carry a low risk of developing DLE.
How Great is the Risk?
Patients who are taking any of the suspected drugs can take them for months or years before symptoms of DLE may appear.Approximately 5-20% of patients taking a high risk drug like procainamide or hydralazine will develop DLE after one or two years (1).Patients who are taking a low-risk medication have less than 1% chance of encountering DLE.
Who Is Affected?
People with Systemic Lupus Erythematosus do not suffer greater chances of contracting Drug Induced Lupus than people without SLE.The anticonvulsant drugs like procainamide or hydralazine that are known to cause DLE do not cause flare-ups in patients with SLE.Rather, anyone who takes the suspect medications that treat chronic diseases suffers a higher risk of being affected by DLE.
Usually these people are male as males are more likely to develop the chronic diseases these drugs treat.The hormonal factor that may cause more women than men to have Systemic Lupus does not apply here.Genetics may increase chances of developing DLE in one way: the slow drug acetylation phenotype.About half of North American whites and blacks are not able to metabolize high-risk drugs fast enough into a non-DLE inducing form.
Drug Induced Lupus Studies
There is much debate as to why DLE occurs.The first case was identified over 50 years ago and research has been ongoing since.The most powerful evidence seems to conclude that it is not the actual medication but the metabolic change to the drug in the body that allows it to react with the immune system.There are several other in-depth theories postulated about the true reason for the occurrence of DLE.
Drug Induced Lupus vs. Systemic Lupus
Symptoms common to SLE but rare to DLE include oral ulcers, sensitivity to UV light, alopecia, and central nervous system disease. The onset of SLE in the elderly may be confused with DLE as the symptoms may be similar and the elderly are typically on several medications.If you are taking a suspect medication, eliminating it might be necessary to determine if the cause is DLE.
The most effective treatment for DLE is to stop the risky medication.Once symptoms disappear the DLE will be in remission unless you resume taking the drug.