<p>Cinacalcet treatment should not be initiated if serum calcium is less than the lower limit of the normal range (8.4 mg/dL). Serum-calcium concentration should be measured before initiation of treatment and within 1 week after starting treatment or adjusting dose, then monthly for secondary hyperparathyroidism and every 2&ndash;3 months for primary hyperparathyroidism and parathyroid carcinoma; treatment should not be initiated in patients with hypocalcaemia; in secondary hyperparathyroidism PTH concentration should be measured 1&ndash;4 weeks after starting treatment or adjusting dose, then every 1&ndash;3 months; dose adjustment may be necessary if smoking started or stopped during treatment; hepatic impairment; pregnancy.</p>