INTERMITTENT INTRAVENOUS FOLLOWED BY INTERMITTENT ORAL 1-ALPHA(OH)D-3TREATMENT OF SECONDARY HYPERPARATHYROIDISM IN UREMIA

Objectives. To examine whether intermittent oral 1 alpha(OH)D-3 treatm ent of patients on haemodialysis with secondary hyperparathyroidism (H PT) was able to maintain the marked suppression of PTH, which previous ly had been induced by an intermittent intravenous administration of 1 alpha(OH)D-2. Simultaneously, the effect of the different routes of a dministration of 1 alpha(OH)D-3 on the circulating levels of N- and C- terminal PTH fragments was measured. Design. An open study of patients on chronic haemodialysis. Setting. Renal division, Rigshospitalet, Co penhagen, Denmark. Subjects. A total of 26 patients starred and five p atients completed the total protocol. Interventions. The treatment pro tocol was divided into three parts: (i) 1 alpha(OH)D-3 administered in travenously for > 300 days; then (ii) 1 alpha(OH)D-3 administered oral ly for 100 days, followed by (iii) 1 alpha(OH)D-3 administered intrave nously again for another 100 days, 1 alpha(OH)D-3 was given three time s a week at the end of each dialysis. Main outcome measures. Intact PT H, N- and C-terminal PTH. Results. Intact PTH levels were significantl y (P < 0.0001) suppressed by 90.4+/-3.3% after 56 days of intermittent intravenous 1 alpha(OH)D-3 treatment, This degree of suppression rema ined stable during the following period of oral treatment and did not change further when intravenous treatment was reinstituted, The circul ating levels of intact PTH and N- and C-terminal iPTH were not influen ced by the administered route of 1 alpha(OH)D-3. Conclusions. Intraven ous 1 alpha(OH)D-3 treatment of the secondary HPT in dialysis patients can safely be changed to oral treatment at the time when optimal supp ression of PTH has been achieved.