Treatment of Polymyalgia Rheumatica (PMR)
Polymyalgia rheumatica (PMR) is a relatively common condition in adults over 50 years old, and more often affects northern European populations including Scandinavians, although it can affect people of any race. Below we will outline the basics of the treatment of polymyalgia rheumatica.
The disease can present suddenly, and patients may wake up with sudden stiffness around their shoulders, neck, and hips. The cause of PMR is unknown, but it can be treated with glucocorticoids.
There is a lack of adequate trials on the treatment of polymyalgia rheumatica, but clinical experience indicates that most cases respond quickly to oral steroids such as prednisone. Starting doses have not been well-defined, but an initial dose of 15 mg/day of prednisone is recommended for most patients. Adjustments can be made for patients with lower body weight, comorbidities, or for more severe symptoms. The American College of Rheumatology recommends a starting range of 12.5-25 mg of prednisone per day. Treatment should be titrated to the lowest effective dose to manage symptoms. If symptoms are not improved within one week, a dose escalation to 20 mg/day may be effective. Divided doses (twice daily) can be used if a single morning dose is not adequate to prevent symptoms later in the day or overnight.
The erythrocyte sedimentation rate (ESR) should be measured as part of the diagnosis of PMR, along with CRP. Both levels should decrease to normal following steroid treatment and symptom improvement. It is not necessary to consistently monitor ESR after the first return visit and when a patient is stabilized on treatment. If ESR or CRP levels remain elevated, a reevaluation of the patient for giant cell arteritis (GCA) should take place. GCA is a similar condition to PMR, and patients with one are more likely to develop the other. GCA can have more severe and damaging symptoms, including visual loss, but can be treated with higher doses of glucocorticoids.
Long-term use of glucocorticoids comes with risks, and monitoring is important throughout the course of therapy. Osteoporosis, hyperglycemia, cataracts, glaucoma, and hypertension are common adverse effects, and approximately half of PMR patients using glucocorticoids had at least one side effect. Cataracts may be more likely to occur in patients with PMR than those using glucocorticoids for other indications.
Because of these risks, alternative therapies should be considered for patients with existing comorbidities of diabetes, hypertension, heart failure, or osteoporosis. Intramuscular methylprednisolone can provide efficacy at a lower cumulative glucocorticoid dose. One randomized controlled trial evaluated methylprednisolone at a dose of 120 mg given every three weeks, and results showed similar efficacy to oral prednisone in PMR. Methotrexate can be considered if a glucocorticoid cannot be used, although it has not been formally studied in PMR, and study results are mixed.
To prevent osteoporosis, all patients starting long-term corticosteroid treatment for PMR should have a baseline bone mineral density and start calcium and vitamin D supplements. Bisphosphonates can be used prophylactically if indicated.
PMR often requires a slow taper off of prednisone to prevent relapses. If the patient shows improvement or remission after 2-4 weeks of treatment, tapering can begin. The dose can be decreased by 2.5 mg per day every 2-4 weeks while the total daily dose is 10 mg or more. Below 10 mg per day, 1 mg decrements are recommended at the 2-4 week interval due to increased sensitivity to dose changes. Patients are more likely to experience a flare if the dose is decreased more rapidly.
When a flare occurs, which is fairly likely during the course even with slow tapering, the last effective dose can be resumed. A relapse does not indicate treatment failure as long as an increase in dose resolves symptoms. If flares are common for a particular patient, the taper interval can be increased to 6-8 weeks.
The good news is that PMR is treatable with glucocorticoids, which will rapidly decrease symptoms in most patients and can be discontinued after 1-2 years. Use caution when adding glucocorticoids to existing medications, and monitor side effects during treatment.
This article was written by Eva Carlson PharmD candidate in collaboration with Eric Christianson, PharmD
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Useful Books For Any Healthcare Professional
- 2015 Recommendations for the Management of Polymyalgia Rheumatica. European League Against Rheumatism/American College of Rheumatology Collaborative Initiative. Arthritis and Rheumatology, Vol. 67, No. 10, October 2015, pp 2569–2580. DOI 10.1002/art.39333.
- Salvarani C, Muratore F. Treatment of polymyalgia rheumatica. UpToDate. Last updated Nov. 23, 2020.
- Salvarani C, Muratore F. Clinical manifestations and diagnosis of polymyalgia rheumatica. UpToDate. Last updated January 13, 2021.