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IMPORTANT SAFETY
INFORMATION
SAMSCA should be
initiated and re-initiated in patients only in a
hospital where serum sodium can be monitored closely.
Too rapid correction of hyponatremia (e.g., > 12 mEq/L/24
hours) can cause osmotic demyelination resulting in
dysarthria, mutism, dysphagia, lethargy, affective
changes, spastic quadriparesis, seizures, coma and
death. In susceptible patients, including those with
severe malnutrition, alcoholism or advanced liver
disease, slower rates of correction may be advisable.
SAMSCA is
contraindicated in the following conditions:
Urgent need to raise
serum sodium acutely, inability of the patient to sense
or appropriately respond to thirst, hypovolemic
hyponatremia, concomitant use of strong CYP 3A
inhibitors, anuric patients
§
Too
Rapid Correction of Serum Sodium Can Cause Serious
Neurologic Sequelae
– During initiation and
after titration monitor patients to assess serum sodium
concentrations and neurologic status. Subjects with
SIADH or very low baseline serum sodium concentrations
may be at greater risk for too-rapid correction of serum
sodium. In patients receiving SAMSCA™ (tolvaptan) who
develop too rapid a rise in serum sodium, discontinue or
interrupt treatment with SAMSCA and consider
administration of hypotonic fluid. Fluid restriction
during the first 24 hours with SAMSCA may increase the
likelihood of overly-rapid correction of serum sodium,
and should generally be avoided.
§
Gastrointestinal Bleeding in Patients with Cirrhosis
– Used only when the need to treat outweighs this risk
§
Dehydration and Hypovolemia
– In patients who develop medically significant signs or
symptoms of hypovolemia, discontinuation is recommended.
Dehydration and hypovolemia can occur, especially in
potentially volume-depleted patients receiving diuretics
or those who are fluid restricted.
§
Co-administration with Hypertonic Saline
– Not recommended
§
Other
Drugs Affecting Exposure to SAMSCA
–
o
CYP 3A
Inhibitors –
Do not use with strong inhibitors of CYP 3A; avoid
concomitant use with moderate CYP 3A inhibitors
o
CYP 3A
Inducers –
Avoid concomitant use with CYP 3A inducers. If
co-administered, the dose of SAMSCA may need to be
increased
o
P-gp
Inhibitors –
The dose of SAMSCA may have to be reduced if
co-administered with P-gp inhibitors
§
Hyperkalemia or Drugs that Increase Serum Potassium
– Monitor serum potassium levels in patients with a
serum potassium > 5 mEq/L and in patients receiving
drugs known to increase serum potassium levels
Pregnancy and Nursing Mothers
– SAMSCA should be used during pregnancy only if the
potential benefit justifies the potential risk to the
fetus. Because many drugs are excreted into human milk
and because of the potential for serious adverse
reactions in nursing infants from SAMSCA, a decision
should be made to discontinue nursing or SAMSCA, taking
into consideration the importance of SAMSCA to the
mother.
Commonly observed adverse reactions
– (incidence > 5%
more than placebo): thirst (16% vs 5%), dry mouth (13%
vs 4%), asthenia (9% vs 4%), constipation (7% vs 2%),
pollakiuria or polyuria (11% vs 3%) and hyperglycemia
(6% vs 1%)
1 Please see
FULL PRESCRIBING INFORMATION including Boxed WARNING
for SAMSCA.
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