Therapeutic Effect of Conivaptan Bolus Dosing in Hyponatremic Neurosurgical Patients

Abstract

We recommend a single 20-mg dose of conivaptan as the preferred initial approach to treating patients with SIADH who are in the neurosurgical intensive care unit. The 24-hour natremic response should then dictate whether additional doses of conivaptan or other therapeutic interventions are required. We believe that such an approach is safe and will result in a controlled and predictable increase in the serum sodium concentration.

Effectiveness and Tolerability of Conivaptan and Tolvaptan for the Treatment of Hyponatremia in Neurocritically Ill Patients

“…To our knowledge, this is the largest study describing the effectiveness and tolerability of conivaptan and tolvaptan for the correction of hyponatremia in neurocritically ill patients. Our observations support the findings of other studies that reported that single doses of vaptans led to an increase in serum sodium level in neurocritically ill patients . Our study demonstrated that vaptans led to an increase in mean serum sodium level of 5.2–7.9 mEq/L at 24 hours that was sustained up to 96 hours after the last dose.…”

“…Our observations support the findings of other studies that reported that single doses of vaptans led to an increase in serum sodium level in neurocritically ill patients. [10][11][12][13]15 Our study demonstrated that vaptans led to an increase in mean serum sodium level of 5.2-7.9 mEq/L at 24 hours that was sustained up to 96 hours after the last dose.…”

“…Table 1 shows the baseline characteristics of these patients. Their mean AE SD age was 57 AE 17 years, 56% were male, median (interquartile range) admission Glasgow Coma Scale score was 13 (8)(9)(10)(11)(12)(13)(14)(15). The mean AE SD serum sodium level was 131 AE 3 mEq/L, and 92% of patients had a serum sodium level of < 135 mEq/L at the time of vaptan administration ( Table 1).…”

“…Tolvaptan's FDA‐approved dosage is 15 mg orally once daily, increased to 30 mg after at least 24 hours to a maximum of 60 mg once daily for a duration of not more than 30 days . However, single doses of both tolvaptan and conivaptan were shown to increase sodium levels in the neurocritical care population in a similar manner as the FDA‐approved dosing . A previous study of 19 neurocritically ill patients receiving a single 20‐ or 40‐mg intravenous bolus dose of conivaptan showed that 69% maintained a rise in serum sodium level of 4 mEq/L for up to 72 hours .…”

“…9 However, single doses of both tolvaptan and conivaptan were shown to increase sodium levels in the neurocritical care population in a similar manner as the FDAapproved dosing. [10][11][12][13] A previous study of 19 neurocritically ill patients receiving a single 20or 40-mg intravenous bolus dose of conivaptan showed that 69% maintained a rise in serum sodium level of 4 mEq/L for up to 72 hours. 12 Another study evaluating the use of tolvaptan in 17 patients with acute brain injury demonstrated that it increased serum sodium concentration by 7.5 mEq/L for up to 48 hours in patients receiving a single dose of 15 mg. 10 The purpose of this study was to describe the effectiveness and tolerability of conivaptan and tolvaptan for the correction of hyponatremia in neurocritically ill patients.…”