AMILORIDE HYDROCHLORIDE AND HYDROCHLOROTHIAZIDE- amiloride hydrochloride and hydrochlorothiazide tablet
Mylan Pharmaceuticals Inc.
DESCRIPTION
Amiloride hydrochloride and hydrochlorothiazide tablets, USP combine the potassium-conserving action of amiloride hydrochloride with the natriuretic action of hydrochlorothiazide.
Amiloride hydrochloride is designated chemically as 3,5-diamino-6-chloro-N -(diaminomethylene)pyrazinecarboxamide monohydrochloride, dihydrate
C6 H8 ClN7 O?HCl?2H2 MW 302.12
Hydrochlorothiazide is designated chemically as 6-chloro-3,4-dihydro-2H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide.
CLINICAL PHARMACOLOGY
Amiloride hydrochloride and hydrochlorothiazide tablets provide diuretic and antihypertensive activity (principally due to the hydrochlorothiazide component), while acting through the amiloride component to prevent the excessive potassium loss that may occur in patients receiving thiazide diuretic. Due to its amiloride component, the urinary excretion of magnesium is less with amiloride and hydrochlorothiazide than with thiazide or loop diuretic used alone. The onset of the diuretic action of this product is within to hours and this action appears to be sustained for approximately 24 hours.
INDICATIONS AND USAGE
Amiloride hydrochloride and hydrochlorothiazide tablets are indicated in those patients with hypertension or with congestive heart failure who develop hypokalemia when thiazides or other kaliuretic diuretics are used alone, or in whom maintenance of normal serum potassium levels is considered to be clinically important, e.g., digitalized patients, or patients with significant cardiac arrhythmias.
The use of potassium-conserving agents is often unnecessary in patients receiving diuretics for uncomplicated essential hypertension when such patients have normal diet.
WARNINGS
Hyperkalemia
Like other potassium-conserving diuretic combinations, amiloride and hydrochlorothiazide may cause hyperkalemia (serum potassium levels greater than 5.5 mEq per liter). In patients without renal impairment or diabetes mellitus, the risk of hyperkalemia with this combination product is about 1% to 2%. This risk is higher in patients with renal impairment or diabetes mellitus (even without recognized diabetic nephropathy). Since hyperkalemia, if uncorrected, is potentially fatal, it is essential to monitor serum potassium levels carefully in any patient receiving amiloride hydrochloride and hydrochlorothiazide, particularly when it is first introduced, at the time of dosage adjustments, and during any illness that could affect renal function.
General
Electrolyte Imbalance and BUN Increases
Determination of serum electrolytes to detect possible electrolyte imbalance should be performed at appropriate intervals.
Patients should be observed for clinical signs of fluid or electrolyte imbalance: i.e., hyponatremia, hypochloremic alkalosis, and hypokalemia. Serum and urine electrolyte determinations are particularly important when the patient is vomiting excessively or receiving parenteral fluids. Warning signs or symptoms of fluid and electrolyte imbalance, irrespective of cause, include dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, confusion, seizures, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, and gastrointestinal disturbances such as nausea and vomiting.
DOSAGE AND ADMINISTRATION
Amiloride hydrochloride and hydrochlorothiazide tablets should be administered with food.
The usual starting dosage is tablet day. The dosage may be increased to tablets day, if necessary. More than tablets of amiloride hydrochloride and hydrochlorothiazide daily usually are not needed and there is no controlled experience with such doses. Hydrochlorothiazide can be given at doses of 12.5 mg to 50 mg per day when used alone. Patients usually do not require doses of hydrochlorothiazide in excess of 50 mg daily when combined with other antihypertensive agents.
The daily dose is usually given as single dose but may be given in divided doses. Once an initial diuresis has been achieved, dosage adjustment may be necessary. Maintenance therapy may be on an intermittent basis.
