Amlodipine and Olmesartan Tablets
TABLE OF CONTENTS
BLACK BOX WARNING
Amlodipine/olmesartan is a combination of the calcium channel receptor blocker (CCB) amlodipine besylate and the angiotensin II receptor blocker (ARB) olmesartan medoxomil.
The amlodipine besylate component of amlodipine/olmesartan is chemically described as 3-ethyl-5-methyl (±)-2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyridinedicarboxylate, monobenzenesulphonate. Amlodipine besylate has empirical formula of C20H25ClN2O5•C6H6O3S, and its molecular weight is 567.1, its structural formula is:
Olmesartan medoxomil, a prodrug, is hydrolyzed to olmesartan during absorption from the gastrointestinal tract.
The olmesartan medoxomil component of amlodipine/olmesartan is chemically described as 2,3-dihydroxy-2-butenyl 4-(1-hydroxy-1-methylethyl)-2-propyl-1-[p-(o-1Htetrazol-5-ylphenyl)benzyl]imidazole-5-carboxylate, cyclic 2,3-carbonate. Its empirical formula is C29H30N6O6. The structural formula for olmesartan medoxomil is:
Amlodipine/olmesartan contains amlodipine besylate, a white to off-white crystalline powder, and olmesartan medoxomil, a white to light yellowish-white powder or crystalline powder. The molecular weights of amlodipine besylate and olmesartan medoxomil are 567.1 and 558.59, respectively. Amlodipine besylate is slightly soluble in water and sparingly soluble in ethanol. Olmesartan medoxomil is practically insoluble in water and sparingly soluble in methanol.
Each tablet of amlodipine/olmesartan also contains the following inactive ingredients: silicified microcrystalline cellulose, pregelatinized starch, croscarmellose sodium, and magnesium stearate. The color coatings contain polyvinyl alcohol, macrogol/polyethylene glycol 3350, titanium dioxide, talc, iron oxide yellow (5/40 mg, 10/20 mg, 10/40 mg tablets), iron oxide red (10/20 mg and 10/40 mg tablets), and iron oxide black (10/20 mg tablets).
|2. INDICATIONS AND USAGE|
Amlodipine/olmesartan is indicated for the treatment of hypertension, alone or with other antihypertensive agents, 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 class to which this drug principally belongs. There are no controlled trials demonstrating risk reduction with amlodipine/olmesartan.
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 also have 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 (for example, 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.
Amlodipine/olmesartan may also be used as initial therapy in patients who are likely to need multiple antihypertensive agents to achieve their blood pressure goals.
Patients with moderate or severe hypertension are at 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 an 8-week, placebo-controlled, parallel-group factorial study provide estimates of the probability of reaching a blood pressure goal with amlodipine/olmesartan compared to amlodipine or olmesartan medoxomil monotherapy. The figures below provide estimates of the likelihood of achieving the targeted systolic or diastolic blood pressure goals with amlodipine/olmesartan 10/40 mg compared with amlodipine or olmesartan medoxomil monotherapy, based upon baseline systolic or diastolic blood pressure. The curve of each treatment group was estimated by logistic regression modeling from all available data of that treatment group. The right tail of each curve is less reliable because of small numbers of subjects with high baseline blood pressures.
The figures above provide an approximation of the likelihood of reaching a targeted blood pressure goal (e.g., Week 8 SBP < 140 mmHg or < 130 mmHg or a DBP < 90 mmHg or < 80 mmHg) for the high-dose treatment groups evaluated in the study. Amlodipine/olmesartan 5/20 mg, the lowest dose combination treatment group, increases the probability of reaching blood pressure goal compared with the highest dose monotherapies, amlodipine 10 mg and olmesartan medoxomil 40 mg.
For example, a patient with a baseline blood pressure of 160/100 mmHg has about a 48% likelihood of achieving a goal of < 140 mmHg (systolic) and a 51% likelihood of achieving a goal of < 90 mmHg (diastolic) on monotherapy with olmesartan medoxomil 40 mg, and about a 46% likelihood of achieving a goal of < 140 mmHg (systolic) and a 60% likelihood of achieving a goal of < 90 mmHg (diastolic) on monotherapy with amlodipine 10 mg. The likelihood of achieving these same goals increases to 63% (systolic) and 71% (diastolic) on amlodipine/olmesartan 5/20 mg, and to 68% (systolic) and 85% (diastolic) on amlodipine/olmesartan 10/40 mg.
|3. DOSAGE AND ADMINISTRATION|
3.1 General Considerations
The side effects of olmesartan medoxomil are generally rare and apparently independent of dose. Those of amlodipine are generally dose-dependent (mostly edema).
Maximum antihypertensive effects are attained within 2 weeks after a change in dose.
Amlodipine/olmesartan may be taken with or without food.
Amlodipine/olmesartan may be administered with other antihypertensive agents.
Dosage may be increased after 2 weeks. The maximum recommended dose of amlodipine/olmesartan is 10/40 mg.
3.2 Replacement Therapy
Amlodipine/olmesartan may be substituted for its individually titrated components.
When substituting for individual components, the dose of one or both of the components can be increased if blood pressure control has not been satisfactory.
3.3 Add-on Therapy
Amlodipine/olmesartan may be used to provide additional blood pressure lowering for patients not adequately controlled with amlodipine (or another dihydropyridine calcium channel blocker) alone or with olmesartan medoxomil (or another angiotensin receptor blocker) alone.
3.4 Initial Therapy
The usual starting dose of amlodipine/olmesartan is 5/20 mg once daily. The dosage can be increased after 1 to 2 weeks of therapy to a maximum dose of one 10/40 mg tablet once daily as needed to control blood pressure.
Initial therapy with amlodipine/olmesartan is not recommended in patients ≥75 years old or with hepatic impairment [See Warnings and Precautions and Use in Specific Populations].
Do not co-administer aliskiren with amlodipine/olmesartan in patients with diabetes [See Drug Interactions].
|5. MECHANISM OF ACTION|
Amlodipine/olmesartan is a combination of two antihypertensive drugs: a dihydropyridine calcium antagonist (calcium ion antagonist or slow-channel blocker), amlodipine besylate, and an angiotensin II receptor blocker, olmesartan medoxomil. The amlodipine component of amlodipine/olmesartan inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle, and the olmesartan medoxomil component of amlodipine/olmesartan blocks the vasoconstrictor effects of angiotensin II.
Amlodipine. Experimental data suggests that amlodipine binds to both dihydropyridine and nonhydropyridine binding sites. The contractile processes of cardiac muscle and vascular smooth muscle are dependent upon the movement of extracellular calcium ions into these cells through specific ion channels. Amlodipine inhibits calcium ion influx across cell membranes selectively, with a greater effect on vascular smooth muscle cells than on cardiac muscle cells. Negative inotropic effects can be detected in vitro but such effects have not been seen in intact animals at therapeutic doses. Serum calcium concentration is not affected by amlodipine. Within the physiologic pH range, amlodipine is an ionized compound (pKa=8.6), and its kinetic interaction with the calcium channel receptor is characterized by a gradual rate of association and dissociation with the receptor binding site, resulting in a gradual onset of effect.
Amlodipine is a peripheral arterial vasodilator that acts directly on vascular smooth muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure.
Olmesartan medoxomil. 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. Olmesartan blocks the vasoconstrictor effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in vascular smooth muscle. Its action is, therefore, independent of the pathways for angiotensin II synthesis.
An AT2 receptor is found also in many tissues, but this receptor is not known to be associated with cardiovascular homeostasis. Olmesartan has more than a 12,500-fold greater affinity for the AT1 receptor than for the AT2 receptor.
Blockade of the renin-angiotensin system with ACE inhibitors, which inhibit the biosynthesis of angiotensin II from angiotensin I, is a mechanism of many drugs used to treat hypertension. ACE inhibitors also inhibit the degradation of bradykinin, a reaction also catalyzed by ACE. Because olmesartan does not inhibit ACE (kininase II), it does not affect the response to bradykinin. Whether this difference has clinical relevance is not yet known.
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 circulating angiotensin II levels do not overcome the effect of olmesartan on blood pressure.
|6. USE IN SPECIFIC POPULATIONS|
6.1 Usage in 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 amlodipine/olmesartan 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 amlodipine/olmesartan, 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 amlodipine/olmesartan for hypotension, oliguria, and hyperkalemia [See Use in Specific Populations].
No teratogenic effects were observed when olmesartan medoxomil was administered to pregnant rats at oral doses up to 1000 mg/kg/day (240 times the maximum recommended human dose (MRHD) on a mg/m2 basis) or pregnant rabbits at oral doses up to 1 mg/kg/day (half the MRHD on a mg/m2 basis; higher doses could not be evaluated for effects on fetal development as they were lethal to the does). In rats, significant decreases in pup birth weight and weight gain were observed at doses ≥1.6 mg/kg/day, and delays in developmental milestones (delayed separation of ear auricular, eruption of lower incisors, appearance of abdominal hair, descent of testes, and separation of eyelids) and dose-dependent increases in the incidence of dilation of the renal pelvis were observed at doses ≥ 8 mg/kg/day. The no observed effect dose for developmental toxicity in rats is 0.3 mg/kg/day, about one-tenth the MRHD of 40 mg/day.
No evidence of teratogenicity or other embryo/fetal toxicity was found when pregnant rats and rabbits were treated orally with amlodipine maleate at doses of up to 10 mg amlodipine/kg/day (respectively about 10 and 20 times the maximum recommended human dose of 10 mg amlodipine on a mg/m2 basis) during their respective periods of major organogenesis. (Calculations based on a patient weight of 60 kg). However, litter size was significantly decreased (by about 50%) and the number of intrauterine deaths was significantly increased (about 5-fold) in rats receiving amlodipine maleate at a dose equivalent to 10 mg amlodipine/kg/day for 14 days before mating and throughout mating and gestation. Amlodipine maleate has been shown to prolong both the gestational period and the duration of labor in rats at this dose. There are no adequate and well-controlled studies in pregnant women. Amlodipine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
6.2 Nursing Mothers
It is not known whether the amlodipine or olmesartan medoxomil components of amlodipine/olmesartan are excreted in human milk, but olmesartan is secreted at low concentration in the milk of lactating rats. Because of the potential for adverse effects on the nursing infant, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
6.3 Pediatric Use
Neonates with a history of in utero exposure to amlodipine/olmesartan:
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.
The safety and effectiveness of amlodipine/olmesartan in pediatric patients have not been established.
The effect of amlodipine on blood pressure in patients less than 6 years of age is not known.
Safety and effectiveness of olmesartan medoxomil in pediatric patients have not been established.
6.4 Geriatric Use
Of the total number of subjects in the double-blind clinical study of amlodipine/olmesartan, 20% (384/1940) were 65 years of age or older and 3% (62/1940) were 75 years or older. No overall differences in safety or effectiveness were observed between subjects 65 years of age or older and younger subjects.
Elderly patients have decreased clearance of amlodipine. Starting amlodipine or adding amlodipine at 2.5 mg in patients ≥75 years old is recommended. The lowest dose of amlodipine/olmesartan is 5/20 mg; therefore, initial therapy with amlodipine/olmesartan is not recommended in patients ≥75 years old.
Amlodipine. Reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Elderly patients have decreased clearance of amlodipine with a resulting increase of AUC of approximately 40% to 60%, and a lower initial dose may be required.
Olmesartan medoxomil. Of the total number of hypertensive patients receiving olmesartan medoxomil in clinical studies, more than 20% were 65 years of age and over, while more than 5% were 75 years of age and older. No overall differences in effectiveness or safety were observed between elderly patients and younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
6.5 Hepatic Impairment
There are no studies of amlodipine/olmesartan in patients with hepatic insufficiency, but both amlodipine and olmesartan medoxomil show moderate increases in exposure in patients with hepatic impairment. Use caution when administering amlodipine/olmesartan to patients with severe hepatic impairment.
Patients with hepatic impairment have decreased clearance of amlodipine. Starting amlodipine or adding amlodipine at 2.5 mg in patients with hepatic impairment is recommended. The lowest dose of amlodipine/olmesartan is 5/20 mg; therefore, initial therapy with amlodipine/olmesartan is not recommended in hepatically impaired patients.
6.6 Renal Impairment
There are no studies of amlodipine/olmesartan in patients with renal impairment.
Amlodipine. The pharmacokinetics of amlodipine are not significantly influenced by renal impairment. Patients with renal failure may therefore receive the usual initial dose. Olmesartan medoxomil. Patients with renal insufficiency have elevated serum concentrations of olmesartan compared with patients with normal renal function. After repeated dosing, AUC was approximately tripled in patients with severe renal impairment (creatinine clearance < 20 mL/min). No initial dosage adjustment is recommended for patients with moderate to marked renal impairment (creatinine clearance < 40 mL/min).
6.7 Black Patients
Of the total number of subjects in the double-blind clinical study of amlodipine/olmesartan, 25% (481/1940) were black patients. Amlodipine/olmesartan was effective in treating black patients (usually a low-renin population), and the magnitude of blood pressure reduction in black patients approached that observed for non-black patients.
|7. WARNINGS AND PRECAUTIONS|
7.1 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 amlodipine/olmesartan as soon as possible [see Use in specific Populations].
7.2 Hypotension in Volume- or Salt-Depleted Patients
Olmesartan medoxomil. Symptomatic hypotension may occur after initiation of treatment with olmesartan medoxomil. Patients with an activated reninangiotensin system, such as volume- and/or salt-depleted patients (e.g., those being treated with high doses of diuretics) may be particularly vulnerable. Treatment with amlodipine/olmesartan should start under close medical supervision. If hypotension does occur, 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.
Amlodipine. Since the vasodilation attributable to amlodipine in amlodipine/olmesartan is gradual in onset, acute hypotension has rarely been reported after oral administration. Nonetheless, caution, as with any other peripheral vasodilator, should be exercised when administering amlodipine/olmesartan, particularly in patients with severe aortic stenosis.
7.4 Patients with Severe Obstructive Coronary Artery Disease
Patients, particularly those with severe obstructive coronary artery disease, may develop increased frequency, duration, or severity of angina or acute myocardial infarction on starting calcium channel blocker therapy or at the time of dosage increase. The mechanism of this effect has not been elucidated.
7.5 Patients with Congestive Heart Failure
Amlodipine. In general, calcium channel blockers should be used with caution in patients with heart failure. Amlodipine (5-10 mg per day) has been studied in a placebo-controlled trial of 1153 patients with NYHA Class III or IV heart failure on stable doses of ACE inhibitor, digoxin, and diuretics. Follow-up was at least 6 months, with a mean of about 14 months. There was no overall adverse effect on survival or cardiac morbidity (as defined by life-threatening arrhythmia, acute myocardial infarction, or hospitalization for worsened heart failure). Amlodipine has been compared to placebo in four 8-12 week studies of patients with NYHA class II/III heart failure, involving a total of 697 patients. In these studies, there was no evidence of worsening of heart failure based on measures of exercise tolerance, NYHA classification, symptoms, or LVEF.
7.6 Patients with Impaired Renal Function
Amlodipine/Olmesartan. There are no studies of amlodipine/olmesartan in patients with renal impairment.
Olmesartan medoxomil. Changes in renal function may be anticipated in susceptible individuals treated with olmesartan medoxomil as a consequence of inhibiting the renin-angiotensin-aldosterone system. In patients whose renal function may depend upon 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 or progressive azotemia and (rarely) with acute renal failure and/or death. Similar effects may occur in patients treated with amlodipine/olmesartan due to the olmesartan medoxomil component.
In studies of ACE inhibitors in patients with unilateral or bilateral renal artery stenosis, increases in serum creatinine or blood urea nitrogen (BUN) have been reported. There has been no long-term use of olmesartan medoxomil in patients with unilateral or bilateral renal artery stenosis, but similar effects would be expected with amlodipine/olmesartan because of the olmesartan medoxomil component.
7.7 Patients with Hepatic Impairment
Amlodipine. Since amlodipine is extensively metabolized by the liver and the plasma elimination half-life (t1/2) is 56 hours in patients with severely impaired hepatic function, caution should be exercised when administering amlodipine/olmesartan to patients with severe hepatic impairment.
Patients with hepatic impairment have decreased clearance of amlodipine. Starting amlodipine or adding amlodipine at 2.5 mg in hepatically impaired patients is recommended. The lowest dose of amlodipine/olmesartan is 5/20 mg; therefore, initial therapy with amlodipine/olmesartan is not recommended in hepatically impaired patients [See Use in Specific Populations].
7.8 Laboratory Tests
Amlodipine/olmesartan. There was a greater decrease in hemoglobin and hematocrit in the combination product compared to either component. Other laboratory changes can usually be attributed to either monotherapy component.
Amlodipine. In post-marketing experience, hepatic enzyme elevations have been reported.
Olmesartan medoxomil. In post-marketing experience, increased blood creatinine levels and hyperkalemia have been reported.
|8. ADVERSE REACTIONS|
8.1 Clinical Trials Experience
Because clinical studies are conducted under widely varying conditions, adverse reaction 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 data described below reflect exposure to amlodipine/olmesartan in more than 1600 patients including more than 1000 exposed for at least 6 months and more than 700 exposed for 1 year. Amlodipine/olmesartan was studied in one placebo-controlled factorial trial. The population had a mean age of 54 years and included approximately 55% males. Seventy-one percent were Caucasian and 25% were Black. Patients received doses ranging from 5/20 mg to 10/40 mg orally once daily.
The overall incidence of adverse reactions on therapy with amlodipine/olmesartan was similar to that seen with corresponding doses of the individual components of amlodipine/olmesartan, and to placebo. The reported adverse reactions were generally mild and seldom led to discontinuation of treatment (2.6% for amlodipine/olmesartan and 6.8% for placebo).
Edema is a known, dose-dependent adverse effect of amlodipine but not of olmesartan medoxomil.
The placebo-subtracted incidence of edema during the 8-week, randomized, double-blind treatment period was highest with amlodipine 10 mg monotherapy. The incidence was significantly reduced when 20 mg or 40 mg of olmesartan medoxomil was added to the 10 mg amlodipine dose.
Table 1. Placebo-Subtracted Incidence of Edema During the Double-Blind Treatment Period
Across all treatment groups, the frequency of edema was generally higher in women than men, as has been observed in previous studies of amlodipine.
Adverse reactions seen at lower rates during the double-blind period also occurred in the patients treated with amlodipine/olmesartan at about the same or greater incidence as in patients receiving placebo. These included hypotension, orthostatic hypotension, rash, pruritus, palpitation, urinary frequency, and nocturia.
The adverse event profile obtained from 44 weeks of open-label combination therapy with amlodipine plus olmesartan medoxomil was similar to that observed during the 8-week, double-blind, placebo-controlled period.
Analyzing the data described above specifically for initial therapy, it was observed that higher doses of amlodipine/olmesartan caused slightly more hypotension and orthostatic symptoms, but not at the recommended starting dose of amlodipine/olmesartan 5/20 mg. No increase in the incidence of syncope or near syncope was observed. The incidences of discontinuation because of any treatment emergent adverse events in the double blind phase are summarized in the table below.
Table 2. Discontinuation for any Treatment Emergent Adverse Event1
Amlodipine has been evaluated for safety in more than 11,000 patients in U.S. and foreign clinical trials. Most adverse reactions reported during therapy with amlodipine were of mild or moderate severity. In controlled clinical trials directly comparing amlodipine (N=1730) in doses up to 10 mg to placebo (N=1250), discontinuation of amlodipine due to adverse reactions was required in only about 1.5% of amlodipinetreated patients and about 1% of placebo-treated patients. The most common side effects were headache and edema. The incidence (%) of dose-related side effects was as follows:
Table 3. Adverse Events of Amlodipine
For several adverse experiences that appear to be drug- and dose-related, there was a greater incidence in women than men associated with amlodipine treatment as shown in the following table:
Table 4. Gender-Related Adverse Events of Amlodipine
Olmesartan medoxomil has been evaluated for safety in more than 3825 patients/subjects, including more than 3275 patients treated for hypertension in controlled trials. This experience included about 900 patients treated for at least 6 months and more than 525 for at least 1 year. Treatment with olmesartan medoxomil was well tolerated, with an incidence of adverse events similar to that seen with placebo. Events were generally mild, transient, and without relationship to the dose of olmesartan medoxomil.
The overall frequency of adverse events was not dose-related. Analysis of gender, age, and race groups demonstrated no differences between olmesartan medoxomil- and placebo-treated patients. The rate of withdrawals due to adverse events in all trials of hypertensive patients was 2.4% (i.e., 79/3278) of patients treated with olmesartan medoxomil and 2.7% (i.e., 32/1179) of control patients. In placebo-controlled trials, the only adverse event that occurred in more than 1% of patients treated with olmesartan medoxomil and at a higher incidence in olmesartan medoxomil treated patients vs. placebo was dizziness (3% vs 1%).
8.2 Post-Marketing Experience
The following adverse reactions have been identified during post-approval use of the individual components of amlodipine/olmesartan. 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.
Amlodipine. The following post-marketing event has been reported infrequently where a causal relationship is uncertain: gynecomastia. In post-marketing experience, jaundice and hepatic enzyme elevations (mostly consistent with cholestasis or hepatitis), in some cases severe enough to require hospitalization, have been reported in association with use of amlodipine.
Olmesartan medoxomil. The following adverse reactions have been reported in post- marketing experience:
Body as a Whole: asthenia, angioedema, anaphylactic reactions, peripheral edema
Gastrointestinal: vomiting, diarrhea
Urogenital System: acute renal failure
Skin and Appendages: alopecia, pruritus, urticaria
There is no information on overdosage with amlodipine/olmesartan in humans.
Amlodipine. Single oral doses of amlodipine maleate equivalent to 40 mg amlodipine/kg and 100 mg amlodipine/kg in mice and rats, respectively, caused deaths. Single oral amlodipine maleate doses equivalent to 4 or more mg amlodipine/kg or higher in dogs (11 or more times the maximum recommended human dose on a mg/m2 basis) caused a marked peripheral vasodilation and hypotension.
Only a few cases of human overdose with amlodipine have been reported. One patient was asymptomatic after a 250-mg ingestion; another, who combined 70 mg of amlodipine with an unknown large quantity of a benzodiazepine, developed refractory shock and died.
The most likely effect of overdose with amlodipine/olmesartan is vasodilation, with consequent hypotension and tachycardia. Simple repletion of central fluid volume (Trendelenburg positioning, infusion of crystalloids) may be sufficient therapy, but pressor agents (norepinephrine or high-dose dopamine) may be required. Overdoses of other dihydropyridine calcium channel blockers are reported to have been treated with calcium chloride and glucagon, but evidence of a dose-response relation has not been seen, and these interventions must be regarded as unproven. With abrupt return of peripheral vascular tone, overdoses of other dihydropyridine calcium channel blockers have sometimes progressed to pulmonary edema, and patients must be monitored for this complication.
If massive overdose should occur, active cardiac and respiratory monitoring should be instituted. Frequent blood pressure measurements are essential. Should hypotension occur, cardiovascular support including elevation of the extremities and the judicious administration of fluids should be initiated. If hypotension remains unresponsive to these conservative measures, administration of vasopressors (such as phenylephrine) should be considered with attention to circulating volume and urine output. Intravenous calcium gluconate may help to reverse the effects of calcium entry blockade. As amlodipine is highly protein bound, hemodialysis is not likely to be of benefit.
Olmesartan medoxomil. Limited data are available related to overdosage in humans. The most likely manifestations of overdosage would be hypotension and tachycardia; bradycardia could be encountered if parasympathetic (vagal) stimulation occurs. If symptomatic hypotension should occur, supportive treatment should be initiated. The dialyzability of olmesartan is unknown.
|10. DRUG INTERACTIONS|
10.1 Drug Interactions with amlodipine/olmesartan
The pharmacokinetics of amlodipine and olmesartan medoxomil are not altered when the drugs are co-administered.
No drug interaction studies have been conducted with amlodipine/olmesartan and other drugs, although studies have been conducted with the individual amlodipine and olmesartan medoxomil components of amlodipine/olmesartan, as described below, and no significant drug interactions have been observed.
10.2 Drug Interactions with Amlodipine
In vitro data indicate that amlodipine has no effect on the human plasma protein binding of digoxin, phenytoin, warfarin, and indomethacin.
Effect of Other Agents on Amlodipine
Cimetidine: Co-administration of amlodipine with cimetidine did not alter the pharmacokinetics of amlodipine.
Grapefruit juice: Co-administration of 240 mL of grapefruit juice with a single oral dose of amlodipine 10 mg in 20 healthy volunteers had no significant effect on the pharmacokinetics of amlodipine.
Maalox® (antacid): Co-administration of the antacid Maalox® with a single dose of amlodipine had no significant effect on the pharmacokinetics of amlodipine.
Sildenafil: A single 100 mg dose of sildenafil in subjects with essential hypertension had no effect on the pharmacokinetic parameters of amlodipine. When amlodipine and sildenafil were used in combination, each agent independently exerted its own blood pressure lowering effect.
Effect of Amlodipine on Other Agents
Atorvastatin: Co-administration of multiple 10 mg doses of amlodipine with 80 mg of atorvastatin resulted in no significant change in the steady state pharmacokinetic parameters of atorvastatin.
Digoxin: Co-administration of amlodipine with digoxin did not change serum digoxin levels or digoxin renal clearance in normal volunteers.
Ethanol (alcohol): Single and multiple 10 mg doses of amlodipine had no significant effect on the pharmacokinetics of ethanol.
Warfarin: Co-administration of amlodipine with warfarin did not change the warfarin prothrombin response time.
In clinical trials, amlodipine has been safely administered with thiazide diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, long-acting nitrates, sublingual nitroglycerin, digoxin, warfarin, non-steroidal anti-inflammatory drugs, antibiotics, and oral hypoglycemic drugs.
10.3 Drug Interactions with Olmesartan Medoxomil
No significant drug interactions were reported in studies in which olmesartan medoxomil was co-administered with digoxin or warfarin in healthy volunteers.
The bioavailability of olmesartan medoxomil was not significantly altered by the co-administration of antacids [Al(OH)3/Mg(OH)2].
Olmesartan medoxomil is not metabolized by the cytochrome P450 system and has no effects on P450 enzymes; thus, interactions with drugs that inhibit, induce, or are metabolized by those enzymes are not expected.
The pharmacokinetics of amlodipine and olmesartan medoxomil from amlodipine/olmesartan are equivalent to the pharmacokinetics of amlodipine and olmesartan medoxomil when administered separately. The bioavailability of both components is well below 100%, but neither component is affected by food. The effective half-lives of amlodipine (45±11 hours) and olmesartan (7±1 hours) result in a 2- to 3-fold accumulation for amlodipine and negligible accumulation for olmesartan with once-daily dosing.
Amlodipine. After oral administration of therapeutic doses of amlodipine, absorption produces peak plasma concentrations between 6 and 12 hours. Absolute bioavailability is estimated as between 64% and 90%.
Olmesartan medoxomil. Olmesartan medoxomil is rapidly and completely bioactivated by ester hydrolysis to olmesartan during absorption from the gastrointestinal tract. The absolute bioavailability of olmesartan medoxomil is approximately 26%. After oral administration, the peak plasma concentration (Cmax) of olmesartan is reached after 1 to 2 hours. Food does not affect the bioavailability of olmesartan medoxomil.
Amlodipine. Ex vivo studies have shown that approximately 93% of the circulating drug is bound to plasma proteins in hypertensive patients. Steady-state plasma levels of amlodipine are reached after 7 to 8 days of consecutive daily dosing.
Olmesartan medoxomil. The volume of distribution of olmesartan is approximately 17 L. Olmesartan is highly bound to plasma proteins (99%) and does not penetrate red blood cells. The protein binding is constant at plasma olmesartan concentrations well above the range achieved with recommended doses.
Metabolism and Excretion
Amlodipine. Amlodipine is extensively (about 90%) converted to inactive metabolites via hepatic metabolism. Elimination from the plasma is biphasic with a terminal elimination half-life of about 30 to 50 hours. Ten percent of the parent compound and 60% of the metabolites are excreted in the urine.
Olmesartan medoxomil. Following the rapid and complete conversion of olmesartan medoxomil to olmesartan during absorption, there is virtually no further metabolism of olmesartan. Total plasma clearance of olmesartan is 1.3 L/h, with a renal clearance of 0.6 L/h. Approximately 35% to 50% of the absorbed dose is recovered in urine while the remainder is eliminated in feces via the bile.
Olmesartan appears to be eliminated in a biphasic manner with a terminal elimination half-life of approximately 13 hours. Olmesartan shows linear pharmacokinetics following single oral doses of up to 320 mg and multiple oral doses of up to 80 mg. Steady-state levels of olmesartan are achieved within 3 to 5 days and no accumulation in plasma occurs with once-daily dosing.
|12. HOW SUPPLIED/STORAGE AND HANDLING|
1) How Available:
a) Brand name: AZOR, by DAIICHI SANKYO.
b) Generic drugs: None.
2) How Supplied:
AZOR™ tablets contain amlodipine besylate at a dose equivalent to 5 or 10 mg amlodipine and olmesartan medoxomil in the strengths described below.
AZOR™ tablets are differentiated by tablet color/size and are debossed with an individual product tablet code on one side. AZOR™ tablets are supplied for oral administration in the following strength and package configurations:
3) Storage: Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Protect from moisture. Dispense in tight container.