Long-term experience of alfacalcidol in renal osteodystrophy.

Thirteen patients receiving regular haemodialysis, with biochemical or radiological evidence of renal osteodystrophy, were treated with alfacalcidol (1 alpha hydroxy vitamin D3) for four years. During the first eighteen months of treatment plasma alkaline phosphatase and serum parathyroid hormone concentrations fell and subperiosteal phalangeal erosions improved. Thereafter plasma alkaline phosphatase and serum parathyroid hormone concentrations rose and after four years' treatment only four patients had a normal plasma alkaline phosphatase, only five a normal serum parathyroid hormone level and in only six had the erosions healed completely. Hypercalcaemia occurred in twelve patients, plasma calcium exceeding 3.0 mmol/l in ten. Plasma calcium rose abruptly close to the time when plasma alkaline phosphatase became normal and often remained raised despite reduction in dosage of alfacalcidol. We have reservations about the ultimate value of long-term treatment with alfacalcidol in haemodialysed patients with renal osteodystrophy and urge caution in its use.