Amdonex At
Amdonex At Uses, Dosage, Side Effects, Food Interaction and all others data.
Amdonex At is a fixed-dose combination of Amlodipine and Atenolol. Amlodipine is a dihydropyridine calcium antagonist that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle; it has a greater effect on vascular smooth muscle than on cardiac muscle. Amlodipine is a peripheral vasodilator that acts directly on vascular smooth muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure. Amlodipine reduces tone, decreases coronary vasoreactivity and lowers cardiac demand by reducing after load. Atenolol is a cardio selective beta-blocker. The cardio-selectivity is dose-related. Atenolol causes a reduction in blood pressure by lowering cardiac output, decreasing the plasma renin activity and sympathetic outflow from CNS. Atenolol also causes a reduction in myocardial oxygen demand by virtue of its negative inotropic and negative chronotropic effects.
Trade Name | Amdonex At |
Generic | Amlodipine + Atenolol |
Type | Tablet |
Therapeutic Class | Combined antihypertensive preparations |
Manufacturer | Aronex Life Sciences Pvt Ltd |
Available Country | India |
Last Updated: | September 19, 2023 at 7:00 am |
Uses
Patients with essential hypertension; Patients with angina pectoris & hypertension as co-existing diseases; In post MI patients; In patients with refractory angina pectoris where nitrate therapy has failed.
Amdonex At is also used to associated treatment for these conditions: Anginal Pain, Cardiovascular Events, Chronic Stable Angina Pectoris, Coronary Artery Disease (CAD), High Blood Pressure (Hypertension), Homozygous Familial Hypercholesterolemia, Hypertension,Essential, Mixed Dyslipidemias, Primary Hypercholesterolemia, Vasospastic AnginaAlcohol Withdrawal Syndrome, Angina Pectoris, Atrial Fibrillation, Heart Failure, High Blood Pressure (Hypertension), Migraine, Myocardial Infarction, Refractory Hypertension, Secondary prevention Myocardial infarction, Supra-ventricular Tachyarrhythmias, Thyrotoxicosis, Ventricular Tachyarrhythmias
How Amdonex At works
Mechanism of action on blood pressure
Amlodipine is considered a peripheral arterial vasodilator that exerts its action directly on vascular smooth muscle to lead to a reduction in peripheral vascular resistance, causing a decrease in blood pressure. Amlodipine is a dihydropyridine calcium antagonist (calcium ion antagonist or slow-channel blocker) that inhibits the influx of calcium ions into both vascular smooth muscle and cardiac muscle. Experimental studies imply that amlodipine binds to both dihydropyridine and nondihydropyridine binding sites, located on cell membranes. The contraction of cardiac muscle and vascular smooth muscle are dependent on the movement of extracellular calcium ions into these cells by specific ion channels. Amlodipine blocks calcium ion influx across cell membranes with selectivity. A stronger effect of amlodipine is exerted on vascular smooth muscle cells than on cardiac muscle cells . Direct actions of amlodipine on vascular smooth muscle result in reduced blood pressure .
Mechanism of action in angina
The exact mechanism by which amlodipine relieves the symptoms of angina have not been fully elucidated to this date, however, the mechanism of action is likely twofold:
Amlodipine has a dilating effect on peripheral arterioles, reducing the total peripheral resistance (afterload) against which the cardiac muscle functions. Since the heart rate remains stable during amlodipine administration, the reduced work of the heart reduces both myocardial energy use and oxygen requirements .
Dilatation of the main coronary arteries and coronary arterioles, both in healthy and ischemic areas, is another possible mechanism of amlodipine reduction of blood pressure. The dilatation causes an increase in myocardial oxygen delivery in patients experiencing coronary artery spasm (Prinzmetal's or variant angina) and reduces coronary vasoconstriction caused by smoking .
Atenolol is a cardioselective beta-blocker, called such because it selectively binds to the β1-adrenergic receptor as an antagonist up to a reported 26 fold more than β2 receptors. Selective activity at the β1 receptor produces cardioselectivity due to the higher population of this receptor in cardiac tissue. Some binding to β2 and possibly β3 receptors can still occur at therapeutic dosages but the effects mediated by antagonizing these are significantly reduced from those of non-selective agents. β1 and β2 receptors are Gs coupled therefore antagonism of their activation reduces activity of adenylyl cyclase and its downstream signalling via cyclic adenosime monophosphate and protein kinase A (PKA).
In cardiomyocytes PKA is thought to mediate activation of L-type calcium channels and ryanodine receptors through their phosphorylation. L-type calcium channels can then provide an initial rise in intracellular calcium and trigger the ryanodine receptors to release calcium stored in the sarcoplasmic reticulum (SR) and increased contractility. PKA also plays a role in the cessation of contraction by phosphorylating phospholamban which in turn increases the affinity of SR Ca2+
Similar inihibitory events occur in the bronchial smooth muscle to mediate relaxation including phosphorylation of myosin light-chain kinase, reducing its affinity for calcium. PKA also inhibits the excitatory Gq coupled pathway by phosphorylating the inositol trisphosphate receptor and phospholipase C resulting in inhibition of intracellular calcium release. Antagonism of this activity by beta-blocker agents like atenolol can thus cause increased bronchoconstriction.
Dosage
Amdonex At dosage
The recommended dosage is Amdonex At one tablet daily. If necessary, the dosage may be increased to two tablets daily or as advised by the physicians. The dosage however should be individualized.
Side Effects
The combination of Amlodipine and Atenolol is well tolerated. Overall side-effects include fatigue, headache, edema, nausea drowsiness, anxiety and depression.
Toxicity
Acute oral toxicity (LD50): 37 mg/kg (mouse) .
Overdose
An overdose of amlodipine could result in a high degree of peripheral vasodilatation with a possibility of reflex tachycardia. Significant and prolonged hypotension leading to shock and fatal outcomes have been reported .
Carcinogenesis, mutagenesis, impairment of fertility
Rats and mice treated with amlodipine maleate in the diet on a long-term basis for up to 2 years demonstrated no evidence of a carcinogenic effect of the drug. For the mouse, the highest dose was comparable to the maximum recommended human dose of 10 mg amlodipine per day. For the rat, the highest dose was measured to be about twice the maximum recommended human dose .
Mutagenicity studies using amlodipine maleate showed no drug-related gene or chromosomal effects .
There was no impact on the fertility of rats given oral amlodipine maleate (males for 64 days and females for 14 days before mating) at doses up to 10 mg amlodipine/kg/day (8 times the maximum recommended human dose) .
Use in pregnancy
The safety of amlodipine in human pregnancy or lactation has not been proven. Amlodipine is therefore considered a pregnancy category C drug . Use amlodipine only if the potential benefit justifies the potential risk .
Use in nursing
Discontinue when administering amlodipine .
LD50 Values
Mouse: 2 g/kg (Oral), 57 mg/kg (IV), 134 mg/kg (IP), 400 mg/kg (SC)
Rat: 2 g/kg (Oral), 77 mg/kg (IV), 600 mg/kg (SC)
Rabbit: 50 mg/kg (IV)
Carcinogenicity & Mutagenicity
Studies in rats and mice at doses of 300 mg/kg/day, equivalent to 150 times maximum recommended human dose, for durations of 18 and 24 months showed no carcinogenicity. One study in rats at doses of 500-1500 mg/kg/day, 250-750 times maximum human dose, resulted in increases benign adrenal medullary tumors in both sexes and increase mammary fibroadenomas in females.
Atenolol showed no mutagenicity in the Ames test using S. typhinarium, dominant lethal test in mice, or in vivo cytogenetics test in chinese hamster ovary cells.
Reproductive Toxicity
No adverse effects on fertility were observed in either male or female mice after receiving doses of 200 mg/kg/day, equivalent to 200 times the maximum human dose. In humans, atenolol is known to cross the placenta and fetuses exposed to the drug have been reported to be smaller than expected considering gestational age. Embryo-fetal resorption has been observed in rats at doses of 50mg/kg/day, 50 times the max human dose, but not in rabbits at doses of 25mg/kg/day.
Lactation
Atenolol appears in breast milk at a ratio of 1.5-6.8 to plasma concentrations. It has been estimated that infant exposure occurs at 5.7-19.2% maternal weight-adjusted dosage. Effects in infants include bradycardia, hypothermia, and lethargy.
Precaution
Bronchospasm: The combination should be used with caution in patients with airway obstruction.
Renal impairment: The combination can be used in patients with renal impairment. However, caution may be necessary if the creatinine clearance is less than 30 ml/min because of possible reduction in the excretion of unchanged Atenolol.
Hepatic impairment: Caution may be necessary in the use of the combination in patients with severe liver damage because of prolongation of the elimination half-life of Amlodipine.
Drug withdrawal: Since coronary heart disease may exist without being recognized, patients should be warned against stopping the drug suddenly. Any discontinuation should be gradual and under observation.
Interaction
Amlodipine has been safely administered with thiazide diuretics, beta blockers, alpha blockers, angiotensin converting enzyme inhibitors, long-acting nitrates, sublingual glyceryl trinitrate, non-steroidal anti-inflammatory agents, antibiotics, and oral hypoglycemic agents. In vitro data from studies with human plasma indicate that amlodipine has no effect on protein binding of the drugs tested (Digoxin, Phenytoin, Warfarin, or Indomethacin).
Atenolol reduces the clearance of Disopyramide by 20%. Additive negative inotropic effects on the heart may be produced. At doses of 1 gm and above, Ampicillin may reduce Atenolol levels. Beta-blockers may decrease tissue sensitivity to Insulin and inhibit Insulin secretion, e.g. in response to oral antidiabetics. Atenolol has less potential for these actions.
Volume of Distribution
21 L/kg , .
Total Vd of 63.8-112.5 L. Atenolol distributes into a central volume of 12.8-17.5 L along with two peripheral compartments with a combined volume of 51-95 L. Distribution takes about 3 hrs for the central compartment, 4 hrs for the shallower peripheral compartment, and 5-6 hrs for the deeper peripheral compartment.
Elimination Route
Amlodipine absorbed slowly and almost completely from the gastrointestinal tract. Peak plasma concentrations are achieved 6-12 hours after oral administration. The estimated bioavailability of amlodipine is 64-90%. Steady-state plasma amlodipine levels are achieved after 7-8 days of consecutive daily dosing. Absorption is not affected by food .
Approximately 50% of an oral dose is absorbed from the gastrointestinal tract, with the remainder being excreted unchanged in the feces. Administering atenolol with food can decrease the AUC by about 20%. While atenolol can cross the blood-brain barrier, it does so slowly and to a small extent.
Half Life
The terminal elimination half-life of about 30–50 hours .
Plasma elimination half-life is 56 hours in patients with impaired hepatic function, titrate slowly when administering this drug to patients with severe hepatic impairment .
6-7 hrs.
Clearance
Total body clearance (CL) has been calculated as 7 ± 1.3 ml/min/kg (0.42 ± 0.078 L/ h/kg) in healthy volunteers , .
Elderly patients show a reduced clearance of amlodipine with an AUC (area under the curve) increase of about 40–60%, and a lower initial dose may be required .
Total clearance is estimated at 97.3-176.3 mL/min with a renal clearance of 95-168 mL/min.
Elimination Route
Elimination from the plasma occurs in a biphasic with a terminal elimination half-life of about 30–50 hours. Steady-state plasma levels of amlodipine are reached after 7-8 days of consecutive daily dosing . Amlodipine is 10% excreted as unchanged drug in the urine. Amlodipine can be initiated at normal doses in patients diagnosed with renal failure , .
85% is eliminated by the kidneys following IV administration with 10% appearing in the feces.
Pregnancy & Breastfeeding use
Pregnancy: The combination should be used during pregnancy only if the expected benefit outweighs the potential fetal risk.
Nursing Mother: The combination should not be used by nursing mothers. If its use is considered necessary, breast-feeding should be stopped.
Contraindication
Hypersensitivity to either component, sinus bradycardia, second and higher degrees of heart block, cardiogenic shock, hypotension, congestive heart failure, poor left ventricular function.
Special Warning
Children with hypertension from 6 years to 17 years of age: 2.5 mg once daily as a starting dose, up-titrated to 5 mg once daily if blood pressure goal is not achieved after 4 weeks. Doses in excess of 5 mg daily have not been studied in pediatric patients.
Children under 6 years old: The effect of amlodipine on blood pressure in patients less than 6 years of age is not known.
Elderly: Amlodipine used at similar doses in elderly or younger patients is equally well tolerated. Normal dosage regimens are recommended in the elderly, but increase of the dosage should take place with care.
Renal impairment: Changes in amlodipine plasma concentrations are not correlated with degree of renal impairment, therefore the normal dosage is recommended. Amlodipine is not dialysable.
Hepatic impairment: Dosage recommendations have not been established in patients with mild to moderate hepatic impairment; therefore dose selection should be cautions and should start at the lower end of the dosing range. The pharmacokinetics of Amlodipine have not been studied in severe hepatic impairment. Amlodipine should be initiated at the lowest dose (2.5 mg once daily) and titrated slowly in patients with severe hepatic impairment.
Safety and effectiveness in pediatric patients have not been established.
Acute Overdose
Though not documented, hypotension and less frequently congestive cardiac failure may occur in cases of overdosage. Unabsorbed drugs may be removed by gastric lavage or administration of activated charcoal. Symptomatic treatment is suggested.
Interaction with other Medicine
Disopyramide: Atenolol reduces the clearance of disopyramide by 20%. Additive negative inotropic effects on the heart may be produced. Ampicillin: at doses of 1 gm and above may reduce Atenolol levels. Oral antidiabetics and insulin: Beta-blockers may decrease tissue sensitivity to insulin and inhibit insulin secretion e.g. in response to oral antidiabetics. Atenolol has less potential for these actions.
Storage Condition
Store in a cool dry place protected from light. Keep out of reach of children.
Innovators Monograph
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FAQ
What is Amdonex At used for?
Amdonex At are widely used as fixed drug combination for treatment of hypertension and chronic stable angina. atenolol and amlodipine combination exerts a superior effect on blood pressure, blood pressure variability, baroreflex sensitivity and end-organ damage. The superior effect of the combination was observed in all four models of hypertension.
Is it safe to take Amdonex At?
Amdonex At may have additive effects in lowering your blood pressure and heart rate. You may experience headache, dizziness, lightheadedness, fainting, and/or changes in pulse or heart beat.
How does Amdonex At work?
Combination of the two drugs results in additive antihypertensive action. Amdonex At works by blocking the action of certain natural chemicals in your body, such as epinephrine, on the heart and blood vessels.
What are the common side effects of Amdonex At?
Common side effects of Amdonex At are include:
Headache, hypotension, dizziness, breathlessness, fatigue, muscle cramps, bradycardia, palpitations, flushing, oedema, dyspnoea, dyspepsia, cold extremities. Drowsiness, chestpain & impotence rarely. Hypersensitivity reactions.
Is Amdonex At safe during pregnancy?
Amdonex At is contraindicated during pregnancy.
Is Amdonex At safe during breastfeeding?
Amdonex At is caution when used during lactation.
How much Amdonex At can I take daily?
Adult: Per tablet contains atenolol 25 or 50 mg and amlodipine 5 mg 1 tab once daily, may increase to 2 tablets daily if needed.
Elderly: Per tablet contains atenolol 25 mg and amlodipine 5 mg Initiate with 1 tablet daily.
What is the indication of Amdonex At?
Take the tablet of Amdonex At with or without food or as directed by your doctor. Swallow the whole tablet with a glass of water. Do not crush, chew, or break it.
Can I drink alcohol with Amdonex At?
You are recommended not to consume alcohol and Amdonex At to avoid unpleasant side effects like lowering blood pressure .
Can I drive after taking Amdonex At ?
Drive with caution,Amdonex At usually causes drowsiness and affects driving ability.
Can Amdonex At effects my liver?
Amdonex At to be taken with caution, especially if you have had a history of liver disease. Your doctor will have to change the dosage depending on your medical condition and your reaction to treatment.
Can Amdonex At affect my kidneys?
Amdonex At to be taken with caution, especially if you have had a history of kidney disease. Your doctor will have to change the dosage depending on your medical condition and your reaction to treatment.