Congestive Heart Failure Post-Myocardial Infarction
The recommended dose of INSPRA is 50 mg once daily. Treatment should be initiated
at 25 mg once daily and titrated to the target dose of 50 mg once daily preferably
within 4 weeks as tolerated by the patient. INSPRA may be administered with or without
food.
Serum potassium should be measured before initiating INSPRA therapy, within the
first week and at one month after the start of treatment or dose adjustment. Serum
potassium should be assessed periodically thereafter. Factors such as patient characteristics
and serum potassium levels may indicate that additional monitoring is appropriate.
(See PRECAUTIONS, Hyperkalemia in Patients Treated for Congestive Heart Failure
and ADVERSE REACTIONS, Clinical Laboratory Test Findings, Congestive Heart Failure
Post-Myocardial Infarction, Potassium.) In EPHESUS, the majority of hyperkalemia
was observed within the first three months after randomization. The dose should
be adjusted based on the serum potassium level and the dose adjustment table shown
below (Table 10).
Table 10. Dose Adjustment in Congestive Heart Failure
Following withholding INSPRA due to serum potassium ≥6.0 mEq/L, INSPRA can be restarted
at a dose of 25 mg QOD when serum potassium levels have fallen below 5.5 mEq/L.
Hypertension
INSPRA may be used alone or in combination with other antihypertensive agents. The
recommended starting dose of INSPRA is 50 mg administered once daily. The full therapeutic
effect of INSPRA is apparent within 4 weeks. For patients with an inadequate blood
pressure response to 50 mg once daily the dosage of INSPRA should be increased to
50 mg twice daily. Higher dosages of INSPRA are not recommended either because they
have no greater effect on blood pressure than 100 mg or because they are associated
with an increased risk of hyperkalemia. (See CLINICAL STUDIES, Hypertension.)
No adjustment of the starting dose is recommended for the elderly or for patients
with mild-to-moderate hepatic impairment. For patients receiving weak CYP3A4 inhibitors,
such as erythromycin, saquinavir, verapamil, and fluconazole the starting dose should
be reduced to 25 mg once daily. (See CONTRAINDICATIONS and PRECAUTIONS, Congestive
Heart Failure Post-Myocardial Infarction and Hypertension, Drug Interactions.)