Overdose
Valsartan
- Hydrochlorothiazide
Limited data are
available related to overdosage in humans. The most likely manifestations of
overdosage would be hypotension and tachycardia; bradycardia could occur from
parasympathetic (vagal) stimulation. Depressed level of consciousness,
circulatory collapse and shock have been reported. If symptomatic hypotension
should occur, supportive treatment should be instituted.
Valsartan is not removed from the plasma by dialysis.
The degree to which hydrochlorothiazide is removed by
hemodialysis has not been established. The most common signs and symptoms
observed in patients are those caused by electrolyte depletion (hypokalemia,
hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis.
If digitalis has also been administered, hypokalemia may accentuate cardiac
arrhythmias.
In rats and marmosets, single oral doses of valsartan up
to 1524 and 762 mg/kg in combination with hydrochlorothiazide at doses up to
476 and 238 mg/kg, respectively, were very well tolerated without any
treatment-related effects. These no adverse effect doses in rats and marmosets,
respectively, represent 46.5 and 23 times the maximum recommended human dose
(MRHD) of valsartan and 188 and 113 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
Valsartan was without grossly
observable adverse effects at single oral doses up to 2000 mg/kg in rats and up
to 1000 mg/kg in marmosets, except for salivation and diarrhea in the rat and vomiting
in the marmoset at the highest dose (60 and 31 times, respectively, the MRHD on
a mg/m² basis). (Calculations assume an oral dose of 320 mg/day and a 60-kg
patient.)
Hydrochlorothiazide
The oral LD50 of
hydrochlorothiazide is greater than 10 g/kg in both mice and rats, which
represents 2027 and 4054 times, respectively, the MRHD on a mg/m² basis.
(Calculations assume an oral dose of 25 mg/day and a 60-kg patient.)
Contraindications
Diovan HCT (valsartan and hydrochlorothiazide, USP) is
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 coadminister aliskiren with Diovan HCT in patients
with diabetes.
Undesirable effects
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
Diovan HCT (valsartan and hydrochlorothiazide, USP) has
been evaluated for safety in more than 5700 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 Diovan HCT 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-hydrochlorothiazide patients and 3.1% of placebo patients. The most
common reasons for discontinuation of therapy with Diovan HCT were headache and
dizziness.
The only adverse reaction that occurred in controlled
clinical trials in at least 2% of patients treated with Diovan HCT and at a
higher incidence in valsartan-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 Diovan HCT.
Other adverse reactions that have been reported with
valsartan-hydrochlorothiazide ( > 0.2% of valsartan-hydrochlorothiazide
patients in controlled clinical trials) without regard to causality, are listed
below:
Cardiovascular: Palpitations and tachycardia
Ear and Labyrinth: Tinnitus and vertigo
Gastrointestinal: Dyspepsia, diarrhea, flatulence,
dry mouth, nausea, abdominal pain, abdominal pain upper, and vomiting
General and Administration Site Conditions: Asthenia,
chest pain, fatigue, peripheral edema and pyrexia
Infections and Infestations: Bronchitis,
bronchitis acute, influenza, gastroenteritis, sinusitis, upper respiratory
tract infection, and urinary tract infection
Investigations: Blood urea increased
Musculoskeletal: Arthralgia, back pain, muscle
cramps, myalgia, and pain in extremity
Nervous System: Dizziness postural, paresthesia,
and somnolence
Psychiatric: Anxiety and insomnia
Renal and Urinary: Pollakiuria
Reproductive System: Erectile dysfunction
Respiratory, Thoracic and Mediastinal: Dyspnea,
cough, nasal congestion, pharyngolaryngeal pain, and sinus congestion
Skin and Subcutaneous Tissue: Hyperhidrosis and
rash
Vascular: Hypotension
Other reported reactions seen less frequently in clinical
trials included abnormal vision, anaphylaxis, bronchospasm, constipation,
depression, dehydration, decreased libido, dysuria, epistaxis, flushing, gout,
increased appetite, muscle weakness, pharyngitis, pruritus, sunburn, syncope,
and viral infection.
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 6
weeks of follow-up was similar in patients treated with Diovan HCT as initial
therapy and in patients treated with valsartan as initial therapy. Comparing
the groups treated with Diovan HCT (force-titrated to 320/25 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 Diovan
HCT and 0% of patients receiving valsartan. There were no reported cases of
syncope in either treatment group. Laboratory changes with Diovan HCT as initial
therapy in patients with severe hypertension were similar to those reported
with Diovan HCT in patients with less severe hypertension.
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).
Other reported reactions seen less frequently in clinical
trials included chest pain, syncope, anorexia, vomiting, and angioedema.
Hydrochlorothiazide: Other adverse reactions not
listed above that have been reported with hydrochlorothiazide, without regard
to causality, are listed below:
Body As A Whole: weakness
Digestive: pancreatitis, jaundice (intrahepatic
cholestatic jaundice), sialadenitis, cramping, gastric irritation
Hematologic: aplastic anemia, agranulocytosis,
leukopenia, hemolytic anemia, thrombocytopenia
Hypersensitivity: purpura, photosensitivity, urticaria,
necrotizing angiitis (vasculitis and cutaneous vasculitis), fever, respiratory
distress including pneumonitis and pulmonary edema, anaphylactic reactions
Metabolic: hyperglycemia, glycosuria,
hyperuricemia
Musculoskeletal: muscle spasm
Nervous System/Psychiatric: restlessness
Renal: renal failure, renal dysfunction,
interstitial nephritis
Skin: erythema multiforme including
Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal
necrolysis
Special Senses: transient blurred vision,
xanthopsia
Clinical Laboratory Test Findings
In controlled clinical trials, clinically important
changes in standard laboratory parameters were rarely associated with
administration of Diovan HCT.
Creatinine/Blood Urea Nitrogen (BUN): Minor
elevations in creatinine and BUN occurred in 2% and 15% respectively, of
patients taking Diovan HCT and 0.4% and 6% respectively, given placebo in
controlled clinical trials
Hemoglobin and Hematocrit: Greater than 20%
decreases in hemoglobin and hematocrit were observed in less than 0.1% of
Diovan HCT patients, compared with 0% in placebo-treated patients
Liver Function Tests: Occasional elevations
(greater than 150%) of liver chemistries occurred in Diovan HCT-treated
patients
Neutropenia: Neutropenia was observed in 0.1% of
patients treated with Diovan HCT and 0.4% of patients treated with placebo
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: There are rare reports of
angioedema. Some of these patients previously experienced angioedema with other
drugs including ACE inhibitors. Diovan HCT should not be re-administered to
patients who have had angioedema.
Digestive: Elevated liver enzymes and very rare
reports of hepatitis
Renal: Impaired renal function
Clinical Laboratory Tests: Hyperkalemia
Dermatologic: Alopecia, bullous dermatitis
Vascular: Vasculitis
Nervous System: Syncope
Rare cases of rhabdomyolysis have been reported in
patients receiving angiotensin II receptor blockers.
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.
Therapeutic indications
Diovan HCT (valsartan and hydrochlorothiazide, USP) 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 hydrochlorothiazide and the ARB class to which
valsartan principally belongs. There are no controlled trials demonstrating
risk reduction with Diovan HCT.
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 1
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
Diovan HCT may be used in patients whose blood pressure
is not adequately controlled on monotherapy.
Replacement Therapy
Diovan HCT may be substituted for the titrated
components.
Initial Therapy
Diovan HCT may be used as initial therapy in patients who
are likely to need multiple drugs to achieve blood pressure goals.
The choice of Diovan HCT 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 provides estimates of the probability of reaching a target blood
pressure with Diovan HCT compared to valsartan or hydrochlorothiazide
monotherapy. The figures below provide estimates of the likelihood of achieving
systolic or diastolic blood pressure control with Diovan HCT 320/25 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
Diovan HCT rises to about 84% (systolic) or 80% (diastolic). The likelihood of
achieving these goals on placebo is about 23% (systolic) or 36% (diastolic).
Pharmacodynamic properties
Valsartan: Valsartan inhibits the pressor effect
of angiotensin II infusions. An oral dose of 80 mg inhibits the pressor effect
by about 80% at peak with approximately 30% inhibition persisting for 24 hours.
No information on the effect of larger doses is available.
Removal of the negative feedback of angiotensin II causes
a 2- to 3-fold rise in plasma renin and consequent rise in angiotensin II
plasma concentration in hypertensive patients. Minimal decreases in plasma
aldosterone were observed after administration of valsartan; very little effect
on serum potassium was observed.
Hydrochlorothiazide: After oral
administration of hydrochlorothiazide, diuresis begins within 2 hours, peaks in
about 4 hours and lasts about 6 to 12 hours.
Drug Interactions
Hydrochlorothiazide
Alcohol, barbiturates, or narcotics: Potentiation
of orthostatic hypotension may occur.
Skeletal muscle relaxants: Possible increased
responsiveness to muscle relaxants such as curare derivatives.
Digitalis glycosides: Thiazide-induced hypokalemia
or hypomagnesemia may predispose the patient to digoxin toxicity.
Pharmacokinetic properties
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 AUC) to valsartan by about 40% and peak plasma concentration (Cmax)
by about 50%. AUC and Cmax 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 (Cmax) 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.
Diovan HCT: Diovan HCT 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 coadministered 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.
Date of revision of the text
July 2015
Fertility, pregnancy and lactation
Pregnancy Category D
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. When pregnancy is detected,
discontinue Diovan HCT as soon as possible. These adverse outcomes are usually
associated with use of these drugs in the second and third trimester of
pregnancy. Most epidemiologic studies examining fetal abnormalities after
exposure to antihypertensive use in the first trimester have not distinguished
drugs affecting the renin-angiotensin system from other antihypertensive
agents. Appropriate management of maternal hypertension during pregnancy is
important to optimize outcomes for both mother and fetus.
In the unusual case that there is no appropriate
alternative to therapy with drugs affecting the renin-angiotensin system for a
particular patient, apprise the mother of the potential risk to the fetus.
Perform serial ultrasound examinations to assess the intra-amniotic
environment. If oligohydramnios is observed, discontinue Diovan HCT, unless it
is considered lifesaving for the mother. Fetal testing may be appropriate,
based on the week of pregnancy. Patients and physicians should be aware,
however, that oligohydramnios may not appear until after the fetus has
sustained irreversible injury. Closely observe infants with histories of in
utero exposure to Diovan HCT for hypotension, oliguria, and hyperkalemia.
Hydrochlorothiazide
Thiazides can cross the placenta, and concentrations
reached in the umbilical vein approach those in the maternal plasma.
Hydrochlorothiazide, like other diuretics, can cause placental hypoperfusion.
It accumulates in the amniotic fluid, with reported concentrations up to 19
times higher than in umbilical vein plasma. Use of thiazides during pregnancy
is associated with a risk of fetal or neonatal jaundice or thrombocytopenia.
Since they do not prevent or alter the course of EPH (Edema, Proteinuria,
Hypertension) gestosis (pre-eclampsia), these drugs should not be used to treat
hypertension in pregnant women. The use of hydrochlorothiazide for other
indications (e.g., heart disease) in pregnancy should be avoided.
Qualitative and quantitative composition
Dosage Forms And Strengths
80/12.5 mg tablets, imprinted CG/HGH (Side 1/Side 2)
160/12.5 mg tablets, imprinted CG/HHH
160/25 mg tablets, imprinted NVR/HXH
320/12.5 mg tablets, imprinted NVR/HIL
320/25 mg tablets, imprinted NVR/CTI
Storage And Handling
Diovan HCT (valsartan and hydrochlorothiazide, USP) is
available as non-scored tablets containing valsartan/hydrochlorothiazide
80/12.5 mg, 160/12.5 mg, 160/25 mg, 320/12.5 mg, and 320/25 mg. Strengths are
available as follows.
80/12.5 mg Tablet - Light orange, ovaloid,
with slightly convex faces debossed CG on 1 side and HGH on the other side.
Bottles of 90...........................................................NDC 0078-0314-34
160/12.5 mg Tablet - Dark red, ovaloid,
with slightly convex faces debossed CG on 1 side and HHH on the other side.
Bottles of 90............................................................NDC 0078-0315-34
Unit Dose (blister pack of 30)................................ NDC 0078-0315-15
160/25 mg Tablet - Brown orange, ovaloid,
with slightly convex faces debossed NVR on 1 side and HXH on the other side.
Bottles of 90............................................................NDC 0078-0383-34
Unit Dose (blister pack of 30)..................................NDC
0078-0383-15
320/12.5 mg Tablet - Pink, ovaloid, with
beveled edge, debossed NVR on 1 side and HIL on the other side.
Bottles of 90............................................................NDC 0078-0471-34
Unit Dose (blister pack of 30)..................................NDC
0078-0471-15
320/25 mg Tablet - Yellow, ovaloid, with
beveled edge, debossed NVR on 1 side and CTI on the other side.
Bottles of 90............................................................NDC 0078-0472-34
Unit Dose (blister pack of 30)..................................NDC
0078-0472-15
Store at 25°C (77°F); excursions permitted
to 15-30°C (59-86°F).
Protect from moisture.
Dispense in tight container (USP).
Distributed by: Novartis
Pharmaceuticals Corporation, East Hanover, New Jersey 07936. Revised: July 2015
Special warnings and precautions for use
WARNINGS
Included as part of the PRECAUTIONS section.
PRECAUTIONS
Fetal Toxicity
Pregnancy Category D
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. When pregnancy is detected,
discontinue Diovan HCT as soon as possible.
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 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 Diovan HCT.
Monitor renal function periodically in these patients. Consider withholding or
discontinuing therapy in patients who develop a clinically significant decrease
in renal function on Diovan HCT.
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
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 Diovan HCT and lithium.
Potassium Abnormalities
Valsartan–Hydrochlorothiazide
In the controlled trials of various doses of Diovan HCT
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), Diovan HCT 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 Diovan 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 Diovan may be required.
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.
Metabolic Disturbances
Hydrochlorothiazide
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 Diovan HCT.
Patient Counseling Information
Information For Patients
Advise the patient to read the FDA-approved patient
labeling (PATIENT INFORMATION).
Pregnancy: Female patients of childbearing age
should be told about the consequences of exposure to Diovan HCT during
pregnancy. Discuss treatment options with women planning to become pregnant.
Patients should be asked to report pregnancies to their physicians 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 MRHD 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 MRHD 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 mcg/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 MRHD 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
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. When pregnancy is detected,
discontinue Diovan HCT as soon as possible. These adverse outcomes are usually
associated with use of these drugs in the second and third trimester of
pregnancy. Most epidemiologic studies examining fetal abnormalities after
exposure to antihypertensive use in the first trimester have not distinguished
drugs affecting the renin-angiotensin system from other antihypertensive
agents. Appropriate management of maternal hypertension during pregnancy is
important to optimize outcomes for both mother and fetus.
In the unusual case that there is no appropriate
alternative to therapy with drugs affecting the renin-angiotensin system for a
particular patient, apprise the mother of the potential risk to the fetus.
Perform serial ultrasound examinations to assess the intra-amniotic
environment. If oligohydramnios is observed, discontinue Diovan HCT, unless it
is considered lifesaving for the mother. Fetal testing may be appropriate,
based on the week of pregnancy. Patients and physicians should be aware,
however, that oligohydramnios may not appear until after the fetus has
sustained irreversible injury. Closely observe infants with histories of in
utero exposure to Diovan HCT for hypotension, oliguria, and hyperkalemia.
Hydrochlorothiazide
Thiazides can cross the placenta, and concentrations
reached in the umbilical vein approach those in the maternal plasma.
Hydrochlorothiazide, like other diuretics, can cause placental hypoperfusion.
It accumulates in the amniotic fluid, with reported concentrations up to 19
times higher than in umbilical vein plasma. Use of thiazides during pregnancy
is associated with a risk of fetal or neonatal jaundice or thrombocytopenia.
Since they do not prevent or alter the course of EPH (Edema, Proteinuria,
Hypertension) gestosis (pre-eclampsia), these drugs should not be used to treat
hypertension in pregnant women. The use of hydrochlorothiazide for other
indications (e.g., heart disease) in pregnancy should be avoided.
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.
Neonates with a history of in utero exposure to Diovan
HCT
If oliguria or hypotension occurs, direct attention
toward support of blood pressure and renal perfusion. Exchange transfusions or
dialysis may be required as a means of reversing hypotension and/or
substituting for disordered renal function.
Geriatric Use
In the controlled clinical trials of Diovan HCT, 764
(17.5%) 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.
Renal Impairment
Safety and effectiveness of Diovan HCT in patients with
severe renal impairment (CrCl &e;30 mL/min) have not been established. No
dose adjustment is required in patients with mild (CrCl 60 to 90 mL/min) or
moderate (CrCl 30 to 60 mL/min) renal impairment.
Hepatic Impairment
Valsartan
No dose adjustment is necessary for patients with
mild-to-moderate liver disease. No dosing recommendations can be provided for
patients with severe liver disease.
Hydrochlorothiazide
Minor alterations of fluid and electrolyte balance may
precipitate hepatic coma in patients with impaired hepatic function or
progressive liver disease.
Dosage (Posology) and method of administration
General Considerations
The usual starting dose is Diovan HCT 160/12.5 mg once
daily. The dosage can be increased after 1 to 2 weeks of therapy to a maximum
of one 320/25 tablet once daily as needed to control blood pressure. Maximum antihypertensive effects are attained within 2
to 4 weeks after a change in dose.
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 Diovan HCT.
A patient who experiences dose-limiting adverse reactions
on either component alone may be switched to Diovan HCT containing a lower dose
of that component in combination with the other to achieve similar blood
pressure reductions. The clinical response to Diovan HCT 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 320/25 mg.
Replacement Therapy
Diovan HCT may be substituted for the titrated
components.
Initial Therapy
Diovan HCT is not recommended as initial therapy in
patients with intravascular volume depletion.
Use With Other Antihypertensive Drugs
Diovan HCT may be administered with other
antihypertensive agents.
Interaction with other medicinal products and other forms of interaction
Hydrochlorothiazide
Alcohol, barbiturates, or narcotics: Potentiation
of orthostatic hypotension may occur.
Skeletal muscle relaxants: Possible increased
responsiveness to muscle relaxants such as curare derivatives.
Digitalis glycosides: Thiazide-induced hypokalemia
or hypomagnesemia may predispose the patient to digoxin toxicity.