Conivaptan

Conivaptan is a prescription medication used to treat the symptoms of hyponatremia (low sodium levels).

• Conivaptan is available under the following different brand names: Vaprisol 

• Common side effects of Conivaptan include:
• Mild fever
• Headache
• Insomnia
• Diarrhea
• Vomiting
• Painful white patches in the mouth or throat, or
• Mild thirst and increased urination

Serious side effects of Conivaptan include:

• hives
• difficult breathing 
• swelling of the face, lips, tongue, or throat.
• a light-headed feeling, 
• low potassium--confusion, uneven heart rate, extreme thirst, increased urination, leg discomfort, muscle weakness, or limp feeling; or
• signs of a rapid increase in sodium levels--trouble speaking, trouble swallowing, weakness, mood changes, muscle spasm or weakness in your arms and legs, seizure.

Rare side effects of Conivaptan include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult dosage

• 5 mg/mL (20 mg/100mL D5W)

Hyponatremia

Adult and geriatric dosage

• Load: 20 mg Intravenous infusion over 30 minutes; and THEN
• 20 mg Intravenous as a continuous infusion over 24 hours for 2-4 days
• After the initial day of treatment, may increase to 40 mg/day if necessary
• Monitor serum sodium and volume status frequently; a significant increase in serum sodium (above 12 mEq/L/24 hours) may result in serious neurologic effects

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Conivaptan has severe interactions with at least 50 other drugs.
• Conivaptan has serious interactions with at least 126 other drugs.
• Conivaptan has moderate interactions with at least 217 other drugs.
• Conivaptan has minor interactions with at least 47 other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

• Hypersensitivity
• Hypovolemic hyponatremia
• Anuria: no benefit can be expected in patients unable to make urine

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Conivaptan?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Conivaptan?”

Cautions

• Is not effective for the treatment of the signs and symptoms of heart failure and is not approved for this indication
• Safety data with hypervolemic hyponatremia associated with heart failure is limited; restrict use to raise serum sodium in such patients only after consideration of other treatment options
• Discontinue in patients who develop hypovolemia or hypotension, and monitor volume status and vital signs; once the patient is again euvolemic and is no longer hypotensive, resume therapy at a reduced dose if the patient remains hyponatremic
• Infusion site reactions are common and can include serious reactions, even with proper infusion rates; administer via large veins, and rotate the infusion site every 24 hours
• Discontinue if undesirably rapid rise in serum Na (above 12 mEq/L/day)
• Osmotic demyelination syndrome: Associated with overly rapid correction of hyponatremia (. e, above 12 mEq/L/day) and results in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma, or death; susceptible patients include those with severe malnutrition, alcoholism, or advanced liver disease, use slower rates of correction
• Hepatic/renal impairment
  • Conivaptan inhibits CYP3A4; rhabdomyolysis occurred in patients who were also receiving a CYP3A-metabolized HMG-CoA reductase inhibitor; avoid concomitant use with drugs eliminated primarily by CYP3A-mediated metabolism; subsequent treatment with CYP3A substrate drugs may be initiated no sooner than 1 week after conivaptan infusion completed
  • Coadministration of digoxin with oral conivaptan resulted in a 1.8- and 1.4-fold increase in digoxin Cmax and AUC, respectively; monitor digoxin levels

Pregnancy and Lactation

• There are no available data on pregnant women to inform a drug-associated risk for major birth defects and miscarriage
• Lactation
  • No information regarding conivaptan or metabolites in human milk, effects of conivaptan on the breastfed infant, or effects of conivaptan on milk production; because of the potential for serious adverse reactions, including electrolyte abnormalities (. g., hypernatremia), hypotension, and volume depletion in breastfed infants, advise a woman not to breastfeed during treatment with conivaptan