Fetal/Neonatal Morbidity and Mortality
Diovan HCT can cause fetal harm when administered to a pregnant woman. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.
Drugs that act on the renin-angiotensin system can cause fetal and neonatal
morbidity and mortality when used in pregnancy. In several dozen published cases,
ACE inhibitor use during the second and third trimesters of pregnancy was associated
with fetal and neonatal injury, including hypotension, neonatal skull hypoplasia,
anuria, reversible or irreversible renal failure, and death [See Use in Specific
Populations].
Intrauterine exposure to thiazide diuretics is associated with fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults.
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 Diovan HCT 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 Diovan HCT, or the treatment should start under close medical supervision.
If hypotension occurs, the patient should be placed in the supine position and, if necessary, given an intravenous infusion of 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.
Impaired Hepatic Function
Hydrochlorothiazide: Thiazide diuretics should be used with caution
in patients with impaired hepatic function or progressive liver disease, since
minor alterations of fluid and electrolyte balance may precipitate hepatic coma.
Valsartan: As the majority of valsartan is eliminated in the
bile, patients with mild-to-moderate hepatic impairment, including patients
with biliary obstructive disorders, showed lower valsartan clearance (higher
AUCs). Care should be exercised in administering Diovan (valsartan) to these
patients.
Hypersensitivity Reaction
Hydrochlorothiazide: 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.
Systemic Lupus Erythematosus
Hydrochlorothiazide: Thiazide diuretics have been reported to
cause exacerbation or activation of systemic lupus erythematosus.
Lithium Interaction
Hydrochlorothiazide: Lithium generally should not be given with
thiazides [See DRUG INTERACTIONS].
Serum Electrolytes
Valsartan – Hydrochlorothiazide: In the controlled trials of
various doses of the combination 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%.
In controlled clinical trials of Diovan HCT (valsartan and hydrochlorothiazide, USP), the average change in serum potassium was near zero in subjects who received Diovan HCT 160/12.5 mg, 320/12.5 mg or 320/25 mg, but the average subject who received Diovan HCT 80/12.5 mg, 80/25 mg or 160/25 mg experienced a mild reduction in serum potassium.
In clinical trials, the opposite effects of valsartan (80, 160 or 320 mg) and hydrochlorothiazide (12.5 mg) on serum potassium approximately balanced each other in many patients. In other patients, one or the other effect may be dominant. Periodic determinations of serum electrolytes to detect possible electrolyte imbalance should be performed at appropriate intervals.
Hydrochlorothiazide: All patients receiving thiazide therapy
should be observed for clinical signs of fluid or electrolyte imbalance: 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.
Hypokalemia may develop, especially with brisk diuresis, when severe cirrhosis is present, or after prolonged therapy.
Interference with adequate oral electrolyte intake will also contribute to hypokalemia. Hypokalemia may cause cardiac arrhythmia and may also sensitize or exaggerate the response of the heart to the toxic effects of digitalis (e.g., increased ventricular irritability).
Although any chloride deficit is generally mild and usually does not require specific treatment except under extraordinary circumstances (as in liver disease or renal disease), chloride replacement may be required in the treatment of metabolic alkalosis.
Dilutional hyponatremia may occur in edematous patients in hot weather; appropriate therapy is water restriction, rather than administration of salt except in rare instances when the hyponatremia is life-threatening. In actual salt depletion, appropriate replacement is the therapy of choice.
Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving thiazide therapy.
In diabetic patients, dosage adjustments of insulin or oral hypoglycemic agents may be required. Hyperglycemia may occur with thiazide diuretics. Thus latent diabetes mellitus may become manifest during thiazide therapy.
The antihypertensive effects of the drug may be enhanced in the postsympathectomy patient.
If progressive renal impairment becomes evident, consider withholding or discontinuing diuretic therapy.
Thiazides have been shown to increase the urinary excretion of magnesium; this may result in hypomagnesemia.
Thiazides may decrease urinary calcium excretion. Thiazides may cause intermittent and slight elevation of serum calcium in the absence of known disorders of calcium metabolism. Marked hypercalcemia may be evidence of hidden hyperparathyroidism. Thiazides should be discontinued before carrying out tests for parathyroid function.
Increases in cholesterol and triglyceride levels may be associated with thiazide diuretic therapy.
Impaired Renal Function
Valsartan: As a consequence of inhibiting the renin-angiotensin-aldosterone
system, changes in renal function may be anticipated in susceptible individuals.
In patients whose renal function may depend on the activity of the renin-angiotensin-aldosterone
system (e.g., patients with severe congestive heart failure), treatment with
angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists
has been associated with oliguria and/or progressive azotemia and (rarely) with
acute renal failure and/or death. Similar outcomes have been reported with Diovan®.
In studies of ACE inhibitors in patients with unilateral or bilateral renal artery stenosis, increases in serum creatinine or blood urea nitrogen have been reported. In a 4-day trial of valsartan in 12 patients with unilateral renal artery stenosis, no significant increases in serum creatinine or blood urea nitrogen were observed. There has been no long-term use of valsartan in patients with unilateral or bilateral renal artery stenosis, but an effect similar to that seen with ACE inhibitors should be anticipated.
Hydrochlorothiazide: Thiazides should be used with caution in
severe renal disease. In patients with renal disease, thiazides may precipitate
azotemia. Cumulative effects of the drug may develop in patients with impaired
renal function.
Information for Patients
Pregnancy: Female patients of childbearing age should be told
that use of drugs like Diovan HCT that act on the renin-angiotensin system during
pregnancy can cause serious problems in the fetus and infant including: low
blood pressure, poor development of skull bones, kidney failure and death. Discuss
other treatment options with female patients planning to become pregnant. Women
using Diovan HCT who become pregnant should notify their physician as soon as
possible.
Symptomatic Hypotension: A patient receiving Diovan HCT should
be cautioned that lightheadedness can occur, especially during the first days
of therapy, and that it should be reported to the prescribing physician. The
patients should be told that if syncope occurs, Diovan HCT should be discontinued
until the physician has been consulted.
All patients should be cautioned 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.
Potassium Supplements: A patient receiving Diovan HCT should
be told not to use potassium supplements or salt substitutes containing potassium
without consulting the prescribing physician.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment of Fertility
Valsartan-Hydrochlorothiazide: No carcinogenicity, mutagenicity
or fertility studies have been conducted with the combination of valsartan and
hydrochlorothiazide. However, these studies have been conducted for valsartan
as well as hydrochlorothiazide alone. Based on the preclinical safety and human
pharmacokinetic studies, there is no indication of any adverse interaction between
valsartan and hydrochlorothiazide.
Valsartan: There was no evidence of carcinogenicity when valsartan
was administered in the diet to mice and rats for up to 2 years at doses up
to 160 and 200 mg/kg/day, respectively. These doses in mice and rats are about
2.6 and 6 times, respectively, the maximum recommended human dose on a mg/m2
basis. (Calculations assume an oral dose of 320 mg/day and a 60-kg patient.)
Mutagenicity assays did not reveal any valsartan-related effects at either
the gene or chromosome level. These assays included bacterial mutagenicity tests
with Salmonella (Ames) and E. coli; a gene mutation test with
Chinese hamster V79 cells; a cytogenetic test with Chinese hamster ovary cells;
and a rat micronucleus test.
Valsartan had no adverse effects on the reproductive performance of male or
female rats at oral doses up to 200 mg/kg/day. This dose is about 6 times the
maximum recommended human dose on a mg/m2 basis. (Calculations assume
an oral dose of 320 mg/day and a 60-kg patient.)
Hydrochlorothiazide: Two-year feeding studies in mice and rats
conducted under the auspices of the National Toxicology Program (NTP) uncovered
no evidence of a carcinogenic potential of hydrochlorothiazide in female mice
(at doses of up to approximately 600 mg/kg/day) or in male and female rats (at
doses of up to approximately 100 mg/kg/day). The NTP, however, found equivocal
evidence for hepatocarcinogenicity in male mice.
Hydrochlorothiazide was not genotoxic in vitro in the Ames mutagenicity
assay of Salmonella Typhimurium strains TA 98, TA 100, TA 1535, TA 1537, and
TA 1538 and in the Chinese Hamster Ovary (CHO) test for chromosomal aberrations,
or in vivo in assays using mouse germinal cell chromosomes, Chinese hamster
bone marrow chromosomes, and the Drosophila sex-linked recessive lethal trait
gene. Positive test results were obtained only in the in vitro CHO Sister
Chromatid Exchange (clastogenicity) and in the Mouse Lymphoma Cell (mutagenicity)
assays, using concentrations of hydrochlorothiazide from 43 to 1300 mcgm/mL,
and in the Aspergillus Nidulans non-disjunction assay at an unspecified concentration.
Hydrochlorothiazide had no adverse effects on the fertility of mice and rats
of either sex in studies wherein these species were exposed, via their diet,
to doses of up to 100 and 4 mg/kg, respectively, prior to mating and throughout
gestation. These doses of hydrochlorothiazide in mice and rats represent 19
and 1.5 times, respectively, the maximum recommended human dose on a mg/m2
basis. (Calculations assume an oral dose of 25 mg/day and a 60-kg patient.)
Developmental Toxicity Studies
Valsartan-Hydrochlorothiazide: There was no evidence of teratogenicity
in mice, rats, or rabbits treated orally with valsartan at doses up to 600,
100 and 10 mg/kg/day, respectively, in combination with hydrochlorothiazide
at doses up to 188, 31 and 3 mg/kg/day. These non-teratogenic doses in mice,
rats and rabbits, respectively, represent 9, 3.5 and 0.5 times the maximum recommended
human dose (MRHD) of valsartan and 38, 13 and 2 times the MRHD of hydrochlorothiazide
on a mg/m2 basis. (Calculations assume an oral dose of 320 mg/day
valsartan in combination with 25 mg/day hydrochlorothiazide and a 60-kg patient.)
Fetotoxicity was observed in association with maternal toxicity in rats and
rabbits at valsartan doses of ≥ 200 and 10 mg/kg/day, respectively, in combination
with hydrochlorothiazide doses of ≥ 63 and 3 mg/kg/day. Fetotoxicity in rats
was considered to be related to decreased fetal weights and included fetal variations
of sternebrae, vertebrae, ribs and/or renal papillae. Fetotoxicity in rabbits
included increased numbers of late resorptions with resultant increases in total
resorptions, postimplantation losses and decreased number of live fetuses. The
no observed adverse effect doses in mice, rats and rabbits for valsartan were
600, 100 and 3 mg/kg/day, respectively, in combination with hydrochlorothiazide
doses of 188, 31 and 1 mg/kg/day. These no adverse effect doses in mice, rats
and rabbits, respectively, represent 9, 3 and 0.18 times the MRHD of valsartan
and 38, 13 and 0.5 times the MRHD of hydrochlorothiazide on a mg/m2
basis. (Calculations assume an oral dose of 320 mg/day valsartan in combination
with 25 mg/day hydrochlorothiazide and a 60-kg patient.)
Valsartan: No teratogenic effects were observed when valsartan
was administered to pregnant mice and rats at oral doses up to 600 mg/kg/day
and to pregnant rabbits at oral doses up to 10 mg/kg/day. However, significant
decreases in fetal weight, pup birth weight, pup survival rate, and slight delays
in developmental milestones were observed in studies in which parental rats
were treated with valsartan at oral, maternally toxic (reduction in body weight
gain and food consumption) doses of 600 mg/kg/day during organogenesis or late
gestation and lactation. In rabbits, fetotoxicity (i.e., resorptions, litter
loss, abortions, and low body weight) associated with maternal toxicity (mortality)
was observed at doses of 5 and 10 mg/kg/day. The no observed adverse effect
doses of 600, 200 and 2 mg/kg/day in mice, rats and rabbits represent 9, 6 and
0.1 times, respectively, the maximum recommended human dose on a mg/m2
basis. (Calculations assume an oral dose of 320 mg/day and a 60-kg patient.)
Hydrochlorothiazide: Under the auspices of the National Toxicology
Program, pregnant mice and rats that received hydrochlorothiazide via gavage
at doses up to 3000 and 1000 mg/kg/day, respectively, on gestation days 6 through
15 showed no evidence of teratogenicity. These doses of hydrochlorothiazide
in mice and rats represent 608 and 405 times, respectively, the maximum recommended
human dose on a mg/m2 basis. (Calculations assume an oral dose of
25 mg/day and a 60-kg patient.)
Use In Specific Populations
Pregnancy
Pregnancy Category D
[See WARNINGS AND PRECAUTIONS]
Diovan HCT, like other drugs that act on the renin-angiotensin system, can cause fetal and neonatal morbidity and death when used during the second or third trimester of pregnancy. Diovan HCT can cause fetal harm when administered to a pregnant woman. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.
Angiotensin II receptor antagonists, like valsartan, and angiotensin-converting enzyme (ACE) inhibitors exert similar effects on the renin-angiotensin system. In several dozen published cases, ACE inhibitor use during the second and third trimesters of pregnancy was associated with fetal and neonatal injury, including hypotension, neonatal skull hypoplasia, anuria, reversible or irreversible renal failure, and death. Oligohydramnios was also reported, presumably from decreased fetal renal function. In this setting, oligohydramnios was associated with fetal limb contractures, craniofacial deformation, and hypoplastic lung development. Prematurity, intrauterine growth retardation, and patent ductus arteriosus were also reported, although it is not clear whether these occurrences were due to exposure to the drug. In a retrospective study, first trimester use of ACE inhibitors, a specific class of drugs acting on the renin-angiotensin system, was associated with a potential risk of birth defects.
When pregnancy occurs in a patient using Diovan HCT, the physician should discontinue Diovan HCT treatment as soon as possible. The physician should inform the patient about potential risks to the fetus based on the time of gestational exposure to Diovan HCT (first trimester only or later). If exposure occurs beyond the first trimester, an ultrasound examination should be done.
In rare cases when another antihypertensive agent can not be used to treat the pregnant patient, serial ultrasound examinations should be performed to assess the intraamniotic environment. Routine fetal testing with non-stress tests, biophysical profiles, and/or contraction stress tests may be appropriate based on gestational age and standards of care in the community. If oligohydramnios occurs in these situations, individualized decisions about continuing or discontinuing Diovan HCT treatment and about pregnancy management should be made by the patient, her physician, and experts in the management of high-risk pregnancy. Patients and physicians should be aware that oligohydramnios may not appear until after the fetus has sustained irreversible injury.
Infants with histories of in utero exposure to Diovan HCT should be
closely observed for hypotension, oliguria, and hyperkalemia. If oliguria occurs,
these infants may require blood pressure and renal perfusion support. Exchange
transfusion or dialysis may be required to reverse hypotension and/or support
decreased renal function.
Healthcare professionals who prescribe drugs acting directly on the renin-angiotensin
system should counsel women of childbearing potential about the risks of these
agents during pregnancy. [See Nonclinical Toxicology].
Nursing Mothers
It is not known whether valsartan is excreted in human milk. Valsartan was excreted into the milk of lactating rats; however, animal breast milk drug levels may not accurately reflect human breast milk levels. Hydrochlorothiazide is excreted in human breast milk. Because many drugs are excreted into human milk and because of the potential for adverse reactions in nursing infants from Diovan HCT, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
Pediatric Use
Safety and effectiveness of Diovan HCT in pediatric patients have not been established.
Geriatric Use
In the controlled clinical trials of Diovan HCT, 764 (17.5%) of patients treated with valsartan-hydrochlorothiazide were ≥ 65 years and 118 (2.7%) were ≥ 75 years. No overall difference in the efficacy or safety of valsartan-hydrochlorothiazide was observed between these patients and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
Last updated on RxList: 8/19/2009