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Rheumatologist Jonathan Krant M.D. and clinical psychologist Laurie Ferguson Ph.D. weigh in on the most effective available psoriatic arthritis treatments and alternative remedies for PsA.
Psoriatic arthritis (PsA) is a serious autoimmune disease that can significantly impair quality of life. It can also cause joint damage and even permanent joint destruction if left untreated. Scientific advances have brought a variety of treatment options for psoriatic arthritis. Gaining a better understanding of these different treatments and how they work will help patients have more productive conversations with their doctors and ultimately improve outcomes.
Physicians used to rely on high dose methotrexate in combination with non-steroidal anti-inflammatories (NSAIDs) to help slow PsA disease progression and protect joints from further damage, but this regimen was problematic for two main reasons: NSAIDs have a high risk of kidney impairment and gastrointestinal side effects including stomach bleeding, and the high doses of methotrexate, up to two grams of cumulative exposure, required liver biopsies due to the risk of liver toxicity.
Today Dr. Krant says rheumatologists have reduced methotrexate dosage to 25 mg per week, which is the same dosage used to treat psoriasis. PsA can have both skin and joint involvement, and unfortunately, many of the drugs used in dermatology to treat psoriasis are not effective for treating both the skin and joint symptoms of PsA. This is concerning given that more than 80 percent of PsA patients have involvement of the large weight bearing joints, as well as sausage-like swelling or deformities of fingers and toes, and back pain.
TNF-alpha inhibitors can reduce the pain, morning stiffness and tender or swollen joints in those with PsA. Newer oral treatments are available that are designed to improve PsA symptoms by inhibiting certain molecules that cause inflammation.
One such oral treatment, apremilast, inhibits the enzyme phosphodiesterase 4, or PDE4, which controls inflammatory activity inside cells. Dr. Krant says he begins patients on a low dose of this drug due to the risk of GI toxicity, but for those patients who tolerate it well, it is an effective treatment.
The newest agent for PsA, just approved by the FDA last year, is secukinumab, given by injection under the skin. Secukinumab is an antibody that binds to the protein interleukin 17A. By binding to IL-17A, secukinumab inhibits the protein’s ability to trigger the inflammatory response. According to Dr. Krant, it has been shown to be “well tolerated and very effective in treating PsA.”
Following are the most common side effects, as well as rarer but more serious side effects, of the medications mentioned in this article. Please note this is not an exhaustive list of all potential side effects:
Dizziness, drowsiness, headache, swollen/tender gums, decreased appetite, reddened eyes and hair loss. More serious side effects include liver damage (methotrexate cannot be given to alcohol users and requires liver monitoring), decrease in blood cells, lung damage, mouth sores, increased risk of infection and lymphoma. This drug requires screening for hepatitis and tuberculosis (TB), as it can activate latent TB that may be in a person’s system.
Urinary tract infections and localized rash, itching or burning. These drugs also can’t be used with methotrexate if the person has liver function abnormalities. More serious side effects can include hepatitis, infections such as TB, allergic reaction, rare neurological complications and a small risk of lymphoma.
Stomach upset, diarrhea, headache, nausea, upper respiratory tract infection, vomiting, runny or stuffy nose, and abdominal pain. More serious side effects include depression, weight loss, migraine and decreased appetite.
Sore throat, diarrhea, upper respiratory tract infection, stuffy or runny nose, oral herpes, or hives. More serious side effects include increased risk of infection including TB, difficulty breathing or swallowing, feeling faint, swelling of the eyes, face, lips, tongue or throat, and chest tightness.
As for drug/drug interactions, Dr. Krant says these are not a significant issue with PsA treatments; however, noncompliance is. If a patient is not taking a drug as prescribed, often due to high insurance copays, that may be a problem. So, for example, instead of taking a drug twice a week, the person may take the drug only once week. This results in a partial response. The problem is that, as Dr. Krant describes, ”we don’t know if someone is failing to respond to the drug or simply not taking it correctly, and no blood test can show noncompliance.” In this case, a patient failing on a particular drug has nothing to do with the drug or its side effects.
With psoriatic arthritis, Dr. Krant says it’s important to treat and treat early. “The sooner you treat, the less you will see deforming arthritis, liver damage, nodules, and/or lung involvement. It’s crucial to start treatment aggressively upfront with biologics by the 12th week, he says. “Waiting too long to treat – even just six months in some cases – can result in severe problems such as claw hand deformities that significantly impact quality of life.