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Tablet
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ORAL
About This Medication
11 DESCRIPTION Valsartan and hydrochlorothiazide tablets, USP are a combination of valsartan, an orally active, specific angiotensin II receptor blocker (ARB) acting on the AT 1 receptor subtype, and hydrochlorothiazide, a diuretic. Valsartan, a nonpeptide molecule, is chemically described as N -(1-oxopentyl)- N -[[2'-(1 H -tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl]-L-Valine. Its molecular formula is C 24 H 29 N 5 O 3 , its molecular weight is 435.52 g/mol, and its structural formula is: Valsartan, USP is almost white, hygroscopic powder. It is practically insoluble in water, freely soluble in anhydrous ethanol and sparingly soluble in methylene chloride. Hydrochlorothiazide, USP is a white or practically white, practically odorless, crystalline powder. It is slightly soluble in water; freely soluble in sodium hydroxide solution, n -butylamine, and in dimethyl formamide; sparingly soluble in methanol; and insoluble in ether, chloroform, and in dilute mineral acids. Hydrochlorothiazide is chemically described as 6-chloro-3,4-dihydro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. Hydrochlorothiazide is a thiazide diuretic. Its molecular formula is C 7 H 8 ClN 3 O 4 S 2 , its molecular weight is 297.74 g/mol, and its structural formula is: Valsartan and hydrochlorothiazide tablets, USP are formulated for oral administration to contain valsartan, USP and hydrochlorothiazide, USP 80 mg/12.5 mg, 160 mg/12.5 mg, 160 mg/25 mg, 320 mg/12.5 mg, and 320 mg/25 mg. The inactive ingredients of the tablets are colloidal silicon dioxide, croscarmellose sodium, hypromellose, iron oxide yellow, polyethylene glycol, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol, talc and titanium dioxide. The 80 mg/12.5 mg tablets also contain FD&C Red No. 40 and ferrosoferric oxide. The 160 mg/12.5 mg tablets also contain iron oxide red. The 160 mg/25 mg tablets also contain iron oxide red and ferrosoferric oxide. The 320 mg/12.5 mg tablets also contain iron oxide red and ferrosoferric oxide. Valsartan Structural Formula Hydrochlorothiazide Structural Formula
Hoạt chất
| Thành phần |
Hàm lượng |
| Hydrochlorothiazide |
- |
| Valsartan |
- |
Chỉ định & Cách dùng
1 INDICATIONS AND USAGE Valsartan and hydrochlorothiazide tablets are 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 hydrochlorothiazide and the angiotensin II receptor blocker (ARB) class to which valsartan principally belongs. There are no controlled trials demonstrating risk reduction with valsartan and hydrochlorothiazide tablets. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program’s Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality have also been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (e.g., patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease). These considerations may guide selection of therapy. Add-On Therapy Valsartan and hydrochlorothiazide tablets may be used in patients whose blood pressure is not adequately controlled on monotherapy. Replacement Therapy Valsartan and hydrochlorothiazide tablets may be substituted for the titrated components. Initial Therapy Valsartan and hydrochlorothiazide tablets may be used as initial therapy in patients who are likely to need multiple drugs to achieve blood pressure goals. The choice of valsartan and hydrochlorothiazide tablets as initial therapy for hypertension should be based on an assessment of potential benefits and risks. Patients with stage 2 hypertension are at a relatively high risk for cardiovascular events (such as strokes, heart attacks, and heart failure), kidney failure, and vision problems, so prompt treatment is clinically relevant. The decision to use a combination as initial therapy should be individualized and should be shaped by considerations such as baseline blood pressure, the target goal, and the incremental likelihood of achieving goal with a combination compared to monotherapy. Individual blood pressure goals may vary based upon the patient’s risk. Data from the high dose multifactorial trial [see Clinical Studies (14.1) ] provides estimates of the probability of reaching a target blood pressure with valsartan and hydrochlorothiazide tablets compared to valsartan or hydrochlorothiazide monotherapy. The figures below provide estimates of the likelihood of achieving systolic or diastolic blood pressure control with valsartan and hydrochlorothiazide tablets 320 mg/25 mg, based upon baseline systolic or diastolic blood pressure. The curve of each treatment group was estimated by logistic regression modeling. The estimated likelihood at the right tail of each curve is less reliable due to small numbers of subjects with high baseline blood pressures. Figure 1: Probability of Achieving Systolic Blood Pressure <140 mmHg at Week 8 Figure 2: Probability of Achieving Diastolic Blood Pressure <90 mmHg at Week 8 Figure 3: Probability of Achieving Systolic Blood Pressure <130 mmHg at Week 8 Figure 4: Probability of Achieving Diastolic Blood Pressure <80 mmHg at Week 8 For example, a patient with a baseline blood pressure of 160/100 mmHg has about a 41% likelihood of achieving a goal of < 140 mmHg (systolic) and 60% likelihood of achieving < 90 mmHg (diastolic) on valsartan alone and the likelihood of achieving these goals on HCTZ alone is about 50% (systolic) or 57% (diastolic). The likelihood of achieving these goals on valsartan and hydrochlorothiazide tablets rises to about 84% (systolic) or 80% (diastolic). The likelihood of achieving these goals on placebo is about 23% (systolic) or 36% (diastolic). Valsartan and hydrochlorothiazide tablet is the combination tablet of valsartan, an angiotensin II receptor blocker (ARB) and hydrochlorothiazide (HCTZ), a diuretic. Valsartan and hydrochlorothiazide tablets are indicated for the treatment of hypertension, to lower blood pressure: In patients not adequately controlled with monotherapy. (1) As initial therapy in patients likely to need multiple drugs to achieve their blood pressure goals. (1) Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. Figure 1 Figure 2 Figure 3 Figure 4
Cơ chế hoạt động
12.1 Mechanism of Action 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. Valsartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT 1 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. There is also an AT 2 receptor found in many tissues, but AT 2 is not known to be associated with cardiovascular homeostasis. Valsartan has much greater affinity (about 20,000-fold) for the AT 1 receptor than for the AT 2 receptor. The primary metabolite of valsartan is essentially inactive with an affinity for the AT 1 receptor about one 200 th that of valsartan itself. Blockade of the renin-angiotensin system with ACE inhibitors, which inhibit the biosynthesis of angiotensin II from angiotensin I, is widely used in the treatment of hypertension. ACE inhibitors also inhibit the degradation of bradykinin, a reaction also catalyzed by ACE. Because valsartan does not inhibit ACE (kininase II), it does not affect the response to bradykinin. Whether this difference has clinical relevance is not yet known. Valsartan does not bind to or block other hormone receptors or ion channels known to be important in cardiovascular regulation. Blockade of the angiotensin II receptor inhibits the negative regulatory feedback of angiotensin II on renin secretion, but the resulting increased plasma renin activity and angiotensin II circulating levels do not overcome the effect of valsartan on blood pressure. Hydrochlorothiazide is a thiazide diuretic. Thiazides affect the renal tubular mechanisms of electrolyte reabsorption, directly increasing excretion of sodium 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 angiotensin II receptor antagonist tends to reverse the potassium loss associated with these diuretics. The mechanism of the antihypertensive effect of thiazides is unknown.
Liều dùng & Cách dùng
2 DOSAGE AND ADMINISTRATION Dose once daily. Titrate as needed to a maximum dose of 320 mg/25 mg. (2) May be used as add-on/switch therapy for patients not adequately controlled on any of the components (valsartan or HCTZ). (2) May be substituted for titrated components. (2.3) 2.1 General Considerations The usual starting dose is valsartan and hydrochlorothiazide tablets 160 mg/12.5 mg once daily. The dosage can be increased after 1 to 2 weeks of therapy to a maximum of one 320 mg/25 mg tablet once daily as needed to control blood pressure [see Clinical Studies (14.2) ]. Maximum antihypertensive effects are attained within 2 to 4 weeks after a change in dose. 2.2 Add-On Therapy A patient whose blood pressure is not adequately controlled with valsartan (or another ARB) alone or hydrochlorothiazide alone may be switched to combination therapy with valsartan and hydrochlorothiazide tablets. A patient who experiences dose-limiting adverse reactions on either component alone may be switched to valsartan and hydrochlorothiazide tablets containing a lower dose of that component in combination with the other to achieve similar blood pressure reductions. The clinical response to valsartan and hydrochlorothiazide tablets should be subsequently evaluated and if blood pressure remains uncontrolled after 3 to 4 weeks of therapy, the dose may be titrated up to a maximum of 320 mg/25 mg. 2.3 Replacement Therapy Valsartan and hydrochlorothiazide tablets may be substituted for the titrated components. 2.4 Initial Therapy Valsartan and hydrochlorothiazide tablets are not recommended as initial therapy in patients with intravascular volume depletion [see Warnings and Precautions (5.2) ]. 2.5 Use with Other Antihypertensive Drugs Valsartan and hydrochlorothiazide tablets may be administered with other antihypertensive agents.
Side Effects Overview
6 ADVERSE REACTIONS The most common reasons for discontinuation of therapy with valsartan and hydrochlorothiazide were headache and dizziness. The only adverse experience that occurred in ≥ 2% of patients treated with valsartan and hydrochlorothiazide and at a higher incidence than placebo was nasopharyngitis (2.4% vs. 1.9%). (6.1) To report SUSPECTED ADVERSE REACTIONS, contact AvKARE at 1-855-361-3993 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reactions rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates. Hypertension Valsartan and hydrochlorothiazide has been evaluated for safety in more than 5,700 patients, including over 990 treated for over 6 months, and over 370 for over 1 year. Adverse experiences have generally been mild and transient in nature and have only infrequently required discontinuation of therapy. The overall incidence of adverse reactions with valsartan and hydrochlorothiazide was comparable to placebo. The overall frequency of adverse reactions was neither dose-related nor related to gender, age, or race. In controlled clinical trials, discontinuation of therapy due to side effects was required in 2.3% of valsartan and hydrochlorothiazide patients and 3.1% of placebo patients. The most common reasons for discontinuation of therapy with valsartan and hydrochlorothiazide were headache and dizziness. The only adverse reaction that occurred in controlled clinical trials in at least 2% of patients treated with valsartan and hydrochlorothiazide and at a higher incidence in valsartan and hydrochlorothiazide (n=4372) than placebo (n=262) patients was nasopharyngitis (2.4% vs. 1.9%). Dose-related orthostatic effects were seen in fewer than 1% of patients. In individual trials, a dose-related increase in the incidence of dizziness was observed in patients treated with valsartan and hydrochlorothiazide. Initial Therapy-Hypertension In a clinical study in patients with severe hypertension (diastolic blood pressure ≥ 110 mmHg and systolic blood pressure ≥ 140 mmHg), the overall pattern of adverse reactions reported through six weeks of follow-up was similar in patients treated with valsartan and hydrochlorothiazide as initial therapy and in patients treated with valsartan as initial therapy. Comparing the groups treated with valsartan and hydrochlorothiazide (force-titrated to 320 mg/25 mg) and valsartan (force-titrated to 320 mg), dizziness was observed in 6% and 2% of patients, respectively. Hypotension was observed in 1% of those patients receiving valsartan and hydrochlorothiazide and 0% of patients receiving valsartan. There were no reported cases of syncope in either treatment group. Laboratory changes with valsartan and hydrochlorothiazide as initial therapy in patients with severe hypertension were similar to those reported with valsartan and hydrochlorothiazide in patients with less severe hypertension [see Clinical Studies (14.2) , Drug Interactions (7) ]. Valsartan: In trials in which valsartan was compared to an ACE inhibitor with or without placebo, the incidence of dry cough was significantly greater in the ACE inhibitor group (7.9%) than in the groups who received valsartan (2.6%) or placebo (1.5%). In a 129-patient trial limited to patients who had had dry cough when they had previously received ACE inhibitors, the incidences of cough in patients who received valsartan, hydrochlorothiazide, or lisinopril were 20%, 19%, 69% respectively (p < 0.001). 6.2 Postmarketing Experience The following additional adverse reactions have been reported in valsartan or valsartan/hydrochlorothiazide postmarketing experience. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Hypersensitivity: Angioedema has been reported. Some of these patients previously experienced angioedema with other drugs including ACE inhibitors. Valsartan and hydrochlorothiazide should not be re-administered to patients who have had angioedema. Digestive: Elevated liver enzymes and reports of hepatitis Musculoskeletal: Rhabdomyolysis Renal: Impaired renal function Dermatologic: Alopecia, bullous dermatitis Vascular: Vasculitis Nervous System: Syncope Hydrochlorothiazide: The following additional adverse reactions have been reported in postmarketing experience with hydrochlorothiazide: Acute renal failure, renal disorder, aplastic anemia, erythema multiforme, pyrexia, muscle spasm, asthenia, acute angle-closure glaucoma, bone marrow failure, worsening of diabetes control, hypokalemia, blood lipids increased, hyponatremia, hypomagnesemia, hypercalcemia, hypochloremic alkalosis, impotence, and visual impairment. Pathological changes in the parathyroid gland of patients with hypercalcemia and hypophosphatemia have been observed in a few patients on prolonged thiazide therapy. If hypercalcemia occurs, further diagnostic evaluation is necessary. Non-melanoma Skin Cancer: Hydrochlorothiazide is associated with an increased risk of non-melanoma skin cancer. In a study conducted in the Sentinel System, increased risk was predominantly for squamous cell carcinoma (SCC) and in white patients taking large cumulative doses. The increased risk for SCC in the overall population was approximately 1 additional case per 16,000 patients per year, and for white patients taking a cumulative dose of ≥ 50,000 mg the risk increase was approximately 1 additional SCC case for every 6,700 patients per year.
Cảnh báo & Thận trọng
5 WARNINGS AND PRECAUTIONS Hypotension: Correct volume depletion prior to initiation. (5.2) Observe for signs of fluid or electrolyte imbalance. (5.9) Monitor renal function and potassium in susceptible patients. (5.3, 5.7) Exacerbation or activation of systemic lupus erythematosus. (5.5) Acute angle-closure glaucoma. (5.8) 5.1 Fetal Toxicity Valsartan and hydrochlorothiazide can cause fetal harm when administered to a pregnant woman. Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations. Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death. Thiazides cross the placenta, and use of thiazides during pregnancy is associated with fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults. When pregnancy is detected, discontinue valsartan and hydrochlorothiazide as soon as possible [see Use in Specific Populations (8.1) ]. 5.2 Hypotension in Volume- and/or Salt-Depleted Patients Excessive reduction of blood pressure was rarely seen (0.7%) in patients with uncomplicated hypertension treated with valsartan and hydrochlorothiazide in controlled trials. In patients with an activated renin-angiotensin system, such as volume- and/or salt-depleted patients receiving high doses of diuretics, symptomatic hypotension may occur. This condition should be corrected prior to administration of valsartan and hydrochlorothiazide, or the treatment should start under close medical supervision. If hypotension occurs, place the patient in the supine position and, if necessary, give intravenous normal saline. A transient hypotensive response is not a contraindication to further treatment, which usually can be continued without difficulty once the blood pressure has stabilized. 5.3 Impaired Renal Function Changes in renal function including acute renal failure can be caused by drugs that inhibit the renin-angiotensin system and by diuretics. Patients whose renal function may depend in part on the activity of the renin-angiotensin system (e.g., patients with renal artery stenosis, chronic kidney disease, severe congestive heart failure, or volume depletion) may be at particular risk of developing acute renal failure on valsartan and hydrochlorothiazide. Monitor renal function periodically in these patients. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on valsartan and hydrochlorothiazide [see Drug Interactions (7) ] . 5.4 Hypersensitivity Reaction Hypersensitivity reactions to hydrochlorothiazide may occur in patients with or without a history of allergy or bronchial asthma, but are more likely in patients with such a history. 5.5 Systemic Lupus Erythematosus Thiazide diuretics have been reported to cause exacerbation or activation of systemic lupus erythematosus. 5.6 Lithium Interaction Increases in serum lithium concentrations and lithium toxicity have been reported with concomitant use of valsartan or thiazide diuretics. Monitor lithium levels in patients receiving valsartan and hydrochlorothiazide tablets and lithium [see Drug Interactions (7) ]. 5.7 Potassium Abnormalities In the controlled trials of various doses of valsartan and hydrochlorothiazide, the incidence of hypertensive patients who developed hypokalemia (serum potassium < 3.5 mEq/L) was 3.0%; the incidence of hyperkalemia (serum potassium > 5.7 mEq/L) was 0.4%. Hydrochlorothiazide can cause hypokalemia and hyponatremia. Hypomagnesemia can result in hypokalemia which appears difficult to treat despite potassium repletion. Drugs that inhibit the renin-angiotensin system can cause hyperkalemia. Monitor serum electrolytes periodically. If hypokalemia is accompanied by clinical signs (e.g., muscular weakness, paresis, or ECG alterations), valsartan and hydrochlorothiazide should be discontinued. Correction of hypokalemia and any coexisting hypomagnesemia is recommended prior to the initiation of thiazides. Some patients with heart failure have developed increases in potassium with valsartan therapy. These effects are usually minor and transient, and they are more likely to occur in patients with pre-existing renal impairment. Dosage reduction and/or discontinuation of the diuretic and/or valsartan may be required [see Adverse Reactions (6.1) ] . 5.8 Acute Myopia and Secondary Angle-Closure Glaucoma Hydrochlorothiazide, a sulfonamide, can cause an idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma. Symptoms include acute onset of decreased visual acuity or ocular pain and typically occur within hours to weeks of drug initiation. Untreated acute angle-closure glaucoma can lead to permanent vision loss. The primary treatment is to discontinue hydrochlorothiazide as rapidly as possible. Prompt medical or surgical treatments may need to be considered if the intraocular pressure remains uncontrolled. Risk factors for developing acute angle-closure glaucoma may include a history of sulfonamide or penicillin allergy. 5.9 Metabolic Disturbances Hydrochlorothiazide may alter glucose tolerance and raise serum levels of cholesterol and triglycerides. Hydrochlorothiazide may raise the serum uric acid level due to reduced clearance of uric acid and may cause or exacerbate hyperuricemia and precipitate gout in susceptible patients. Hydrochlorothiazide decreases urinary calcium excretion and may cause elevations of serum calcium. Monitor calcium levels in patients with hypercalcemia receiving valsartan and hydrochlorothiazide tablets.
Chống chỉ định
4 CONTRAINDICATIONS Valsartan and hydrochlorothiazide tablets are contraindicated in patients who are hypersensitive to any component of this product. Because of the hydrochlorothiazide component, this product is contraindicated in patients with anuria or hypersensitivity to other sulfonamide-derived drugs. Do not co-administer aliskiren with valsartan and hydrochlorothiazide tablets in patients with diabetes [see Drug Interactions (7) ] . Anuria; Hypersensitivity to any sulfonamide-derived drugs or any component; Do not co-administer aliskiren with valsartan and hydrochlorothiazide tablets in patients with diabetes. (4)
Dược động học
12.3 Pharmacokinetics Valsartan: Valsartan peak plasma concentration is reached 2 to 4 hours after dosing. Valsartan shows bi-exponential decay kinetics following intravenous administration, with an average elimination half-life of about 6 hours. Absolute bioavailability for the capsule formulation is about 25% (range 10% to 35%). Food decreases the exposure (as measured by area under the curve [AUC]) to valsartan by about 40% and peak plasma concentration (C max ) by about 50%. AUC and C max values of valsartan increase approximately linearly with increasing dose over the clinical dosing range. Valsartan does not accumulate appreciably in plasma following repeated administration. Hydrochlorothiazide: The estimated absolute bioavailability of hydrochlorothiazide after oral administration is about 70%. Peak plasma hydrochlorothiazide concentrations (C max ) are reached within 2 to 5 hours after oral administration. There is no clinically significant effect of food on the bioavailability of hydrochlorothiazide. Hydrochlorothiazide binds to albumin (40% to 70%) and distributes into erythrocytes. Following oral administration, plasma hydrochlorothiazide concentrations decline bi-exponentially, with a mean distribution half-life of about 2 hours and an elimination half-life of about 10 hours. Valsartan and hydrochlorothiazide: Valsartan and hydrochlorothiazide may be administered with or without food. Distribution Valsartan: The steady-state volume of distribution of valsartan after intravenous administration is small (17 L), indicating that valsartan does not distribute into tissues extensively. Valsartan is highly bound to serum proteins (95%), mainly serum albumin. Metabolism Valsartan: The primary metabolite, accounting for about 9% of dose, is valeryl 4-hydroxy valsartan. In vitro metabolism studies involving recombinant CYP 450 enzymes indicated that the CYP 2C9 isoenzyme is responsible for the formation of valeryl-4-hydroxy valsartan. Valsartan does not inhibit CYP 450 isozymes at clinically relevant concentrations. CYP 450 mediated drug interaction between valsartan and co-administered drugs are unlikely because of the low extent of metabolism. Hydrochlorothiazide: Is not metabolized. Excretion Valsartan: Valsartan, when administered as an oral solution, is primarily recovered in feces (about 83% of dose) and urine (about 13% of dose). The recovery is mainly as unchanged drug, with only about 20% of dose recovered as metabolites. Following intravenous administration, plasma clearance of valsartan is about 2 L/h and its renal clearance is 0.62 L/h (about 30% of total clearance). Hydrochlorothiazide: About 70% of an orally administered dose of hydrochlorothiazide is eliminated in the urine as unchanged drug. Specific Populations Geriatric: Exposure (measured by AUC) to valsartan is higher by 70% and the half-life is longer by 35% in the elderly than in the young. A limited amount of data suggest that the systemic clearance of hydrochlorothiazide is reduced in both healthy and hypertensive elderly subjects compared to young healthy volunteers. Gender: Pharmacokinetics of valsartan do not differ significantly between males and females. Race: Pharmacokinetic differences due to race have not been studied. Renal Insufficiency: There is no apparent correlation between renal function (measured by creatinine clearance) and exposure (measured by AUC) to valsartan in patients with different degrees of renal impairment. Valsartan has not been studied in patients with severe impairment of renal function (creatinine clearance < 10 mL/min). Valsartan is not removed from the plasma by hemodialysis. In a study in individuals with impaired renal function, the mean elimination half-life of hydrochlorothiazide was doubled in individuals with mild/moderate renal impairment (30 < CrCl < 90 mL/min) and tripled in severe renal impairment (CrCl ≤ 30 mL/min), compared to individuals with normal renal function (CrCl > 90 mL/min) [see Use in Specific Populations (8.6) ]. Hepatic Insufficiency: On average, patients with mild-to-moderate chronic liver disease have twice the exposure (measured by AUC values) to valsartan of healthy volunteers (matched by age, sex, and weight) [see Use in Specific Populations (8.7) ]. Drug Interactions Valsartan No clinically significant pharmacokinetic interactions were observed when valsartan was co-administered with amlodipine, atenolol, cimetidine, digoxin, furosemide, glyburide, hydrochlorothiazide, or indomethacin. The valsartan-atenolol combination was more antihypertensive than either component, but it did not lower the heart rate more than atenolol alone. Co-administration of valsartan and warfarin did not change the pharmacokinetics of valsartan or the time-course of the anticoagulant properties of warfarin. Transporters: The results from an in vitro study with human liver tissue indicate that valsartan is a substrate of the hepatic uptake transporter OATP1B1 and the hepatic efflux transporter MRP2. Co-administration of inhibitors of the uptake transporter (rifampin, cyclosporine) or efflux transporter (ritonavir) may increase the systemic exposure to valsartan. Hydrochlorothiazide: Drugs that alter gastrointestinal motility: The bioavailability of thiazide-type diuretics may be increased by anticholinergic agents (e.g., atropine, biperiden), apparently due to a decrease in gastrointestinal motility and the stomach emptying rate. Conversely, pro-kinetic drugs may decrease the bioavailability of thiazide diuretics. Cholestyramine: In a dedicated drug interaction study, administration of cholestyramine 2 hours before hydrochlorothiazide resulted in a 70% reduction in exposure to hydrochlorothiazide. Further, administration of hydrochlorothiazide 2 hours before cholestyramine resulted in 35% reduction in exposure to hydrochlorothiazide. Antineoplastic agents (e.g., cyclophosphamide, methotrexate): Concomitant use of thiazide diuretics may reduce renal excretion of cytotoxic agents and enhance their myelosuppressive effects.