Intravenous pamidronate for refractory rheumatoid arthritis

Patients with rheumatoid arthritis may be resistant to conventional treatment with disease-modifying antirheumatic drugs (DMARDs). On the other hand, biologic therapy is costly and may be inconvenient for many patients. Pamidronate is a potent bisphosphonate with the capacity of modifying the biological activity of the immune system cells. It may thus be used as an anti-inflammatory agent in patients with inflammatory joint diseases.

To assess the effectiveness of pamidronate in the management of rheumatoid arthritis, we selected 38 patients with rheumatoid arthritis to enroll in a pilot study to receive pamidronate and conventional treatment with prednisolone and DMARDs in combination. These patients received 60 mg of pamidronate for 3 consecutive months and were followed for 6 months since the first infusion.

The mean visual analogue score (VAS) and disease activity score (DAS28) fell steadily until one month after the third infusion. However, no improvements were observed during the 3 months after the last infusion of the drug. All patients, except one, reported decreased pain in response to 3 consecutive pulses of pamidronate and most had improvements in the assessed laboratory and clinical indices. The drug was tolerated well in our patients.

Pamidronate infusions had beneficial effects on various clinical and laboratory parameters of patients, but alleviation of symptoms were temporary and did not last for more than 6 months. This treatment option can be a choice for difficult cases of rheumatoid arthritis with severe pain and osteoporosis.