Thiazide-induced euvolemic hyponatremia with associated hypochloremia
A 42-year-old white male was admitted to the Burn Unit with 15% Total Body Surface Area (TBSA) deep-partial thickness burns to his upper and lower extremities resulting from misuse of an accelerant. There was no evidence of trauma, inhalation injury, or loss of consciousness. The patient was intoxicated when the injury occurred.
|Vital Signs||Weight: 160 lb, Temperature: 99.0°F, BP: 150/90 mm Hg, HR: 100 bpm, RR: 18|
|Chest X-ray||No acute changes, chronic obstructive lung disease pattern|
|EKG||Normal sinus rhythm at 100, nonspecific ST-T wave changes and voltage criteria for left ventricular hypertrophy (LVH). Remainder unremarkable.|
|VITAL SIGNS||LAB VALUES|
|150/90||100||160||30||405||201||126||Patient diagnosed with euvolemic hyponatremia based on laboratory findings. Patient first received normal saline solution, then a loading dose of VAPRISOL 20-mg IV was administered over 30 minutes, followed by a 20-mg continuous IV infusion to be administered over 24 hours.|
|Day 1||130/72||90||160||60||—||—||134||Patient admitted to the OR. A 20-mg continuous IV infusion of VAPRISOL was administered over 24 hours, including during the procedure.|
|Day 2||136/78||84||160||50||208||80||138||VAPRISOL infusion discontinued.|
|Day 3||—||—||—||—||—||—||137||Remained in-patient for post-surgical observation.|
|Day 4||—||—||—||—||—||—||139||Serum sodium level maintained within normal range*; patient discharged to his home.|
*The effect of VAPRISOL on the maintenance of serum sodium concentration is not known.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.