MICARDIS HCT- telmisartan and hydrochlorothiazide tablet
Boehringer Ingelheim Pharmaceuticals, Inc.
WARNING: FETAL TOXICITY
When pregnancy is detected, discontinue MICARDIS HCT as soon as possible [see Warnings and Precautions (5.1)].
Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus [see Warnings and Precautions (5.1)].
1??INDICATIONS AND USAGE
MICARDIS HCT (telmisartan and hydrochlorothiazide) is indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including the classes to which this drug principally belongs. There are no controlled trials demonstrating risk reduction with MICARDIS HCT.
MICARDIS HCT is not indicated for initial therapy for the treatment of hypertension [see Dosage and Administration (2.1)].
MICARDIS HCT may be used alone or in combination with other antihypertensive agents.
2??DOSAGE AND ADMINISTRATION
2.1?Dosing Information
Initiate a patient whose blood pressure is not adequately controlled with telmisartan monotherapy 80 mg on MICARDIS HCT, 80 mg/12.5 mg once daily. Dose can be titrated up to 160 mg/25 mg after 2 to 4 weeks, if necessary.
2.2?Dose Adjustment for Hepatic Impairment
Initiate patients with biliary obstructive disorders or hepatic insufficiency under close medical supervision using the 40 mg/12.5 mg combination. MICARDIS HCT tablets are not recommended for patients with severe hepatic impairment [see Use in Specific Populations (8.6), and Clinical Pharmacology (12.3)].
2.3?Important Administration Instructions
MICARDIS HCT tablets should not be removed from blisters until immediately before administration.
CONTRAINDICATIONS
MICARDIS HCT is contraindicated:
In patients who are hypersensitive to any component of this product [see Warnings and Precautions (5.5)].
In patients with anuria.
For co-administration with aliskiren in patients with diabetes [see Drug Interactions (7.4)].
DESCRIPTION
MICARDIS HCT tablets are a combination of telmisartan, an orally active angiotensin II antagonist acting on the AT1 receptor subtype, and hydrochlorothiazide, a thiazide diuretic.
Telmisartan, a non-peptide molecule, is chemically described as 4?-[(1,4'-dimethyl-2'-propyl[2,6'-bi-1H-benzimidazol]-1?-yl)methyl]-[1,1'-biphenyl]-2-carboxylic acid. Its empirical formula is C33 H30 N4 O2 , its molecular weight is 514.63.
Telmisartan is a white to slightly yellowish solid. It is practically insoluble in water and in the pH range of 3 to 9, sparingly soluble in strong acid (except insoluble in hydrochloric acid), and soluble in strong base.
Hydrochlorothiazide is a white, or practically white, practically odorless, crystalline powder with a molecular weight of 297.74. It is slightly soluble in water, and freely soluble in sodium hydroxide solution. Hydrochlorothiazide is chemically described as 6-chloro-3,4-dihydro-2H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. Its empirical formula is C7 H8 ClN3 O4 S2 .
MICARDIS HCT tablets are formulated for oral administration in three combinations of 40 mg/12.5 mg, 80 mg/12.5 mg, and 80 mg/25 mg telmisartan and hydrochlorothiazide, respectively. The tablets contain the following inactive ingredients: sodium hydroxide, meglumine, povidone, sorbitol, magnesium stearate, lactose monohydrate, microcrystalline cellulose, maize starch, and sodium starch glycolate. As coloring agents, the 40 mg/12.5 mg and 80 mg/12.5 mg tablets contain ferric oxide red, and the 80 mg/25 mg tablets contain ferric oxide yellow. MICARDIS HCT tablets are hygroscopic and require protection from moisture.
12??CLINICAL PHARMACOLOGY
12.1?Mechanism of Action
MICARDIS HCT
MICARDIS HCT is a combination of two drugs with antihypertensive properties: a thiazide diuretic, hydrochlorothiazide, and an angiotensin II receptor blocker (ARB), telmisartan.
Telmisartan
Angiotensin II is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II). Angiotensin II is the principal pressor agent of the renin-angiotensin system, with effects that include vasoconstriction, stimulation of synthesis and release of aldosterone, cardiac stimulation, and renal reabsorption of sodium. Telmisartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in many tissues, such as vascular smooth muscle and the adrenal gland. Its action is therefore independent of the pathways for angiotensin II synthesis.
Hydrochlorothiazide
Hydrochlorothiazide is a thiazide diuretic. Thiazides affect the renal tubular mechanisms of electrolyte reabsorption, directly increasing excretion of sodium salt and chloride in approximately equivalent amounts. Indirectly, the diuretic action of hydrochlorothiazide reduces plasma volume, with consequent increases in plasma renin activity, increases in aldosterone secretion, increases in urinary potassium loss, and decreases in serum potassium. The renin-aldosterone link is mediated by angiotensin II, so co-administration of an ARB tends to reverse the potassium loss associated with these diuretics. The mechanism of the antihypertensive effect of thiazides is not fully understood.
PATIENT COUNSELING INFORMATION
Advise the patient to read the FDA-approved patient labeling (Patient Information).
Pregnancy
Advise female patients of childbearing age about the consequences of exposure to MICARDIS HCT during pregnancy. Discuss treatment options with women planning to become pregnant. Tell patients to report pregnancies to their physicians as soon as possible [see Warnings and Precautions (5.1)].
Symptomatic Hypotension and Syncope
Advise patients that lightheadedness can occur, especially during the first days of therapy, and to report it to their healthcare provider. Inform patients that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to an excessive fall in blood pressure, with the same consequences of lightheadedness and possible syncope. Advise patients to contact their healthcare provider if syncope occurs [see Warnings and Precautions (5.2)].
Potassium Supplements
Advise patients not to use potassium supplements or salt substitutes that contain potassium without consulting the prescribing healthcare provider [see Warnings and Precautions (5.4) and Drug Interactions (7.1)].
Acute Myopia and Secondary Angle-Closure Glaucoma
Advise patients to discontinue MICARDIS HCT and seek immediate medical attention if they experience symptoms of Acute Myopia or Secondary Angle-Closure Glaucoma [see Warnings and Precautions.
