Euvolemic hyponatremia secondary to mild renal insufficiency
In this patient with euvolemic hyponatremia and a history of both cardiac and pulmonary disease, and chronic renal insufficiency, VAPRISOL was selected as treatment to raise serum sodium and to try to avoid excess sodium and fluid overload.
The patient is a 70-year-old Hispanic male with a long medical history who was brought to his physician by family members after they noted increasing fatigue, restlessness, and gait abnormalities. Laboratory tests showed a serum sodium of 123 mEq/L, indicative of hyponatremia; the patient was admitted to the hospital.*
|Vital Signs||BP: 140/78 mm Hg, HR: 88 bpm, temperature: 98.4° F, RR: 12, weight: 172 lb|
|Lungs||Coarse inspiratory crackles|
|EKG||Left bundle branch block|
|Chest X-ray||Cardiomegaly, no effusions|
|Labs||Sodium 123 mEq/L, BUN/Cr 43/1.2, creatinine clearance 63 mL/min|
|VITAL SIGNS||LAB VALUES|
|130/60||72||172||—||265||20||123||A loading dose of VAPRISOL 20-mg IV administered over 30 minutes, followed by a 20-mg continuous IV infusion administered over 24 hours and fluid restriction to 1 L/day|
|Day 1||130/66||76||170||2400||279||25||128||A 40-mg continuous IV infusion of VAPRISOL administered over 24 hours|
|Day 2||132/64||70||170||2000||291||33||131||A 40-mg continuous IV infusion of VAPRISOL administered over 24 hours|
|Day 3||136/68||66||170||1200||280||33||133||VAPRISOL discontinued|
|Day 4||—||—||—||—||280||28||—||Fluid restriction 1 L/day; discharged|
|136/70||64||170||—||—||—||138||Patient no longer restricting fluids|
*In clinical studies of Vaprisol, the adverse event profile in elderly patients was similar to that seen in the general population.1
Indication: VAPRISOL is indicated to raise serum sodium in hospitalized patients with euvolemic and hypervolemic hyponatremia.
Important Limitations: VAPRISOL has not been shown to be effective for the treatment of the signs and symptoms of heart failure and is not approved for this indication. It has not been established that raising serum sodium with VAPRISOL provides a symptomatic benefit to patients.
IMPORTANT SAFETY INFORMATION
VAPRISOL is contraindicated in patients with hypovolemic hyponatremia. The coadministration of VAPRISOL with potent CYP3A inhibitors, such as ketoconazole, itraconazole, clarithromycin, ritonavir, and indinavir, is contraindicated. In addition, no benefit can be expected in patients unable to make urine.
WARNINGS & PRECAUTIONS
Hyponatremia associated with heart failure: Safety data on the use of VAPRISOL in these patients are limited. Consider other treatment options.
Overly rapid correction of serum sodium: Monitor serum sodium, volume and neurologic status and if the patient develops an undesirably rapid rate of rise of serum, VAPRISOL should be discontinued. If serum sodium concentration continues to rise, VAPRISOL should not be resumed. Serious neurologic sequelae, including osmotic demyelination syndrome, can result from over rapid correction of serum sodium. In susceptible patients, including those with severe malnutrition, alcoholism or advanced liver disease, slower rates of correction should be used.
Hypovolemia or Hypotension: For patients who develop hypovolemia or hypotension while receiving VAPRISOL, VAPRISOL should be discontinued, and volume status and vital signs should be monitored.
Infusion site reactions: Serious reactions have occurred. Administer through large veins and change infusion site every 24 hours.
The most common adverse reactions (incidence ≥10%) reported in clinical trials were infusion site reactions (including phlebitis), pyrexia, hypokalemia, headache and orthostatic hypotension.
Potent CYP3A inhibitors may increase the exposure of conivaptan and are contraindicated. Generally avoid CYP3A substrates. Exposure to coadministered digoxin may be increased and digoxin levels should be monitored.
USE IN SPECIAL POPULATIONS
Use in Patients with Hepatic Impairment
In patients with moderate to severe hepatic impairment, initiate VAPRISOL with a loading dose of 10 mg over 30 minutes followed by 10 mg/day as a continuous infusion for 2 to 4 days. If no rise in serum sodium, VAPRISOL may be titrated upward to 20 mg/day.