Effect of warfarin sodium therapy on excretion of 4-carboxy-L-glutamic acid in scleroderma, dermatomyositis, and myositis ossificans progressiva.

The effect of warfarin sodium on excretion of calcium, phosphorus, and 4-carboxy-L-glutamic acid (Gla) was studied in 5 patients with ectopic calcification (2 with scleroderma, 1 with dermatomyositis, and 2 with myositis ossificans progressiva). Warfarin reduced urinary excretion of Gla in all patients, but no changes in calcium and phosphorus excretion or in objective parameters of calcinosis were observed during 6-36 months of treatment. Two patients experienced hemorrhagic complications during therapy, emphasizing a hazard of long-term anticoagulation treatment. Since ectopic calcium deposits contain Gla-rich protein, suppression of Gla synthesis by warfarin sodium over a longer period may prevent deposition and allow removal of existing calcinosis deposits.