Endocrine Abstracts

Introduction: Cinacalcet is an oral calcimimetic indicated in treatment of primary hyperparathyroidism in patients who are unable to undergo parathyroidectomy: do not accept surgery, there is failure of previous surgery or serious comorbidity that makes surgery impossible.

Methods: Descriptive study that includes nine patients with primary hyperparathyroidism who have completed at least 48 months of treatment with cinacalcet (seven patients refusal to parathyroidectomy and two surgery not possible due to comorbidities). We recorded clinical and biochemical data at baseline and after 3, 6, 12, 24 and 48 months of treatment.

Results: Median time of treatment was 49 months. After 12 months serum calcium was significantly decreased as compared to baseline (10.12 vs 11.59 mg/dl P=0.008) and phosphorus levels were significantly increased (2.84 vs 2.45 mg/dl P=0.021). No significant differences were observed in PTH levels (155.45 vs 136.9 pg/ml P=0.6). No further variation was observed after 24 and 48 months compared to 12 months follow up except for an increase in PTH to baseline levels. As compared to baseline, after 4 years of therapy, serum calcium remained significantly decreased (10.13 vs 11.59 mg/dl P=0.008) and serum phosphorus significantly increased (2.93 vs 2.45 mg/dl P=0.02). Normocalcemia (S-Ca <10.2 mg/dl) was achieved in 55.7% of patients. Usually the medication was well-tolerated and no serious adverse events were observed.

Conclusion: Hypercalcemia is rapidly improved by Cinacalcet and remains stable after 48 months follow-up. Cinacalcet is an effective and safe alternative in non-surgical treatment of primary hyperparathyroidism.