Published: 2 March 2017
Prescriber Update 38(1): 11-12
The Centre for Adverse Reactions Monitoring (CARM) recently received a report of probable drug-induced lupus (DIL) in a patient taking mesalazine1. Anti-histone antibodies were detected1. The dose of mesalazine was gradually reduced and subsequently stopped, with improvement of symptoms1.
Drug-mediated disruption of immune tolerance is believed to be involved in the development of DIL, but the pathogenesis is not fully understood3.
DIL is a separate diagnosis to drug-induced flares of pre-existing or latent systemic lupus erythematosus (SLE)2. However, it can be difficult to distinguish idiopathic SLE from DIL in a patient taking a medicine associated with DIL.
Patients with DIL usually experience mild or few lupus-like symptoms initially. These symptoms include fever, malaise, weight loss, arthritis, arthralgia and myalgia3. Symptoms generally worsen the longer the patient is maintained on the suspect medicine3. Some symptoms such as malar or discoid rash, photosensitivity, oral ulcers, hair loss and renal or neurological disorders are common in SLE, but are uncommon in DIL3.
The latent period between starting the medicine and first symptoms appearing ranges from one month to more than 10 years2.
Certain types of antinuclear antibodies, such as anti-histone antibodies, can help to confirm a diagnosis of DIL3. Although these autoantibodies are also common in SLE, patients with SLE usually have additional autoantibodies such as antibodies against double stranded DNA3. Therefore, when a diagnosis of SLE or DIL cannot be clearly distinguished on clinical grounds, the presence of double stranded DNA antibodies should be considered as evidence against a diagnosis of DIL3.
Medicines associated with DIL are classified as high, moderate, low or very low risk3. There are up to 58 medicines that have been reported to induce autoimmunity and, less frequently, lupus-like disease3. Examples of medicines reported in association with DIL are summarised in Table 1.
Medicines that are associated with DIL should be avoided in patients with SLE3.
|TNFα inhibitors (eg, adalimumab)||Low/very low|
*These medicines are no longer available in New Zealand
The suspect medicine should be stopped2. Symptoms generally improve within one to two weeks of stopping the medicine3. Autoantibodies eventually normalise but can take as long as one to two years to disappear3.
No specific treatment is usually required2. However, the use of non-steroidal anti-inflammatory drugs (NSAIDs) and oral corticosteroids (eg, prednisone) may be useful if severe manifestations such as pericarditis with tamponade, debilitating polyarthritis or glomerulonephritis develop3.
Procainamide is the most common medicine reported to CARM in association with DIL reactions. However, procainamide is no longer available and the last report received for this medicine was in 1978. Other medicines reported include adalimumab (13 reports), infliximab (five reports), mesalazine and methyldopa (three reports each).
Please continue to report any adverse reactions to CARM. Reports can be submitted on paper or electronically (https://nzphvc.otago.ac.nz/).