Drug related arthritis, similar to the lupus variant, resolves shortly after the offending drug is discontinued. And although both conditions can be caused by a large number of offending drugs, most disorders are caused by a handful of specific drugs such as penicillamine.
Diagnostic Difficulties
However, diagnosing drug related conditions is not always an easy task. With the steady influx of new drugs to the market, diagnosis can remain elusive. For instance the anti-tumor necrosis factor agents have recently been linked to drug related lupus and to lung problems in patients with rheumatoid arthritis. Patients who have been prescribed these medications and developed lupus-like conditions may not be aware of the connection.
Diagnosis is particularly important for affected patients. With a correct diagnosis, the responsible drug can be stopped and symptoms, along with possible complications, can be minimized. In addition, with proper diagnosis, patients wouldn’t be inappropriately prescribed corticosteroids and other immunosuppressant agents, drugs with their own history of side effects.
Drug Related Lupus
Drug related lupus can cause symptoms of arthritis and rash as well as pulmonary and cardiac symptoms. Penicillamine, gold salts, and sulphasalazine compounds are all responsible although most conditions are caused by procainamide, hydralazine, and isoniazid. Some rheumatologists consider drug related lupus and drug related arthritis to be identical disorders. Both conditions cause arthritis and arthralgia. Drug related lupus, however, is more likely to affect the lungs, heart, and skin, and to cause a positive ANA test result.
Drug Related Pulmonary Problems in RA
Recently, there have been reports of pulmonary problems occurring in patients with rheumatoid arthritis prescribed methotrexate and anti-tumor necrosis factor (anti-TNF) agents, including etanercept. These symptoms include a worsening of intersitial pulmonary fibrosis, acute pneumonitis, and the acute development of pulmonary infiltrates.
Drug Related Myopathy
A number of drugs have been implicated in causing muscle weakness, particularly weakness of the proximal muscles in the arms and legs. Symptoms often occur insidiously, after weeks of months of drug use. Offending agents include alcohol, chloroquine, statin cholesterol-lowering agents, cocaine, penicillamine and zidovudine.
Drugs that can induce Arthritis
Drug related arthritis is thought to be caused by a hypersensitivity reaction to certain offending agents. Drugs known to cause drug related arthritis are similar to those known to cause drug related lupus and include penicillamine, isoniazid, hydralazine, sulfur containing compounds including iron sulfate, procainaminde, doxycycline, chloroquine, quinine, hormones, antihypertensive agents, vaccines, allergen extracts, and blood products
Infliximab has also been reported to accelerate the development of pulmonary disease in patients with rheumatoid arthritis. Corticosteroids are also known to induce the development of osteoarthritis, complicating symptoms in patients with rheumatoid arthritis.
Diagnosis
A careful medication history is required for a diagnosis of drug related arthritis. Diagnostic criteria have not been established although a reduction in symptoms and eventual remission after the suspect drug has been withdrawn can be used to establish diagnosis.
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