Low-dose methotrexate in rheumatoid arthritis: a potential risk factor for bisphosphonate-induced osteonecrosis of the jaw

Bisphosphonate-induced osteonecrosis of the jaw [BIONJ] is a relatively new pathological condition which was first described in the year 2003. The prevalence of BIONJ in patients on oral formulations is around 0.05% within the first 3 years and increases up to 0.2% after 4 years of consumption. Proven systemic risk factors like anemia, uncontrolled diabetes, corticosteroid therapy, and chemotherapy in neoplastic diseases [e.g., high doses of methotrexate up to 30 mg daily] significantly increase the chances of acquiring BIONJ. We present three patients with osteoporosis and rheumatoid arthritis [RA] who consumed oral bisphosphonates [alendronate] for less than 1 year and developed BIONJ within 2 to 5 months of undergoing a traumatic dental procedure. The patients also gave a history of consuming low doses of methotrexate [disease-modifying anti-rheumatic drugs] up to 20 mg weekly for 4 to 10 years. No history of steroid consumption was given by any of the patients. This case series highlights the possibility of rheumatoid arthritis and low-dose methotrexate being potential risk factors for BIONJ. This may be on account of the synergistic effect of methotrexate and bisphosphonates and the pro-inflammatory state created by RA which increased the risk of acquiring BIONJ.