Pharmaceutica Analytica Acta

Abstract

Intermittent Dosing of Cinacalcet is also Effective in Treating Secondary Hyperparathyroidism in Hemodialysis Patients

Abdullah Khalaf Al-Hwiesh and Ibrahiem Saeed Abdul-Rahman

Background: The calcimimetic, cinacalcet hydrochloride acting on the calcium-sensing receptors is being used quite often in the management of secondary hyperparathyroidism (SHPT). It is given in daily dose of 30-180 mg but there have not been enough comparative trials with intermittent dosing schedule. Aim: To evaluate effectiveness of daily cinacalcet hydrochloride dose and its 3 weekly doses in reducing serum intact PTH levels and relative concentrations of calcium and phosphorous in patients with end stage renal diseases (ESRD) with SHPT on maintenance hemodialysis (HD). Material and methods: Chronic kidney disease (CKD) patients (n=29) who were receiving daily dose (OD) of cinacalcet for SHPT for I year were shifted to an intermittent dosing regimen of cinacalcet at the end of each hemodialysis session (HD), 3 times per week (study patients). After taking baseline measurements of PTH, its monthly assessment along with serum calcium, phosphorous and alkaline phosphatase level estimations at 1, 3, 6, 9 and 12 months were then compared with the baseline levels. Results: Overall the mean intact PTH value was 174.2 + 16.8 pg/ml at the end of one year treatment prior to the study, while receiving a mean dose of 83.7 � 11 mg cinacalcet OD. This controlled value of PTH did not show any statistically significant difference over the next 12 months when the study patients were given intermittent dosing (3/ week) at the end of each hemodialysis session. Similarly the calcium values did not change to a significant level in the study subjects, although the serum phosphorus showed a significant rise at the end of the study period (p=0.003). Conclusion: Cinacalcet effectively controls parathyroid hormone levels and uncontrolled secondary hyperparathyroidism both when given daily and intermittently (3/week). Frequent monitoring and adequate replacement with calcium and vitamin D sterols prevent hypocalcemia with cinacalcet therapy. Thus intermittent dosing of cinacalcet is an excellent cost-effective therapeutic option in HD patients with SHPT. In addition, it improves drug compliance.