Amlopril

Amlopril Uses, Dosage, Side Effects, Food Interaction and all others data.

The synthesis of atenolol resulted from attempts to produce a β-adrenoceptor antagonist that would competitively block β1 (cardiac) receptors but have no effect on β2-receptors. It is classified as a β1 selective (cardioselective) β-adrenergic receptor antagonist with no membranestability activity and no partial agonist activity. It is markedly the most hydrophilic of the currently available β- blockers and thus penetrates the lipid of cell membranes poorly

Atenolol is a cardio-selective beta-blocker and as such exerts most of its effects on the heart. It acts as an antagonist to sympathetic innervation and prevents increases in heart rate, electrical conductivity, and contractility in the heart due to increased release of norepinephrine from the peripheral nervous system. Together the decreases in contractility and rate produce a reduction in cardiac output resulting in a compensatory increase in peripheral vascular resistance in the short-term. This response later declines to baseline with long-term use of atenolol. More importantly, this reduction in the work demanded of the myocardium also reduces oxygen demand which provides therapeutic benefit by reducing the mismatch of oxygen supply and demand in settings where coronary blood flow is limited, such as in coronary atherosclerosis. Reducing oxygen demand, particularly due to exercise, can reduce the frequency of angina pectoris symptoms and potentially improve survival of the remaining myocardium after myocardial infarction. The decrease in rate of sinoatrial node potentials, electrical conduction, slowing of potentials traveling through the atrioventricular node, and reduced frequency of ectopic potentials due to blockade of adrenergic beta receptors has led to benefit in arrhythmic conditions such as atrial fibrillation by controlling the rate of action potential generation and allowing for more effective coordinated contractions. Since a degree of sympathetic activity is necessary to maintain cardiac function, the reduced contractility induced by atenolol may precipitate or worsen heart failure, especially during volume overload.

The effects of atenolol on blood pressure have been established, although it is less effective than alternative beta-blockers, but the mechanism has not yet been characterized. As a β1 selective drug, it does not act via the vasodilation produced by non-selective agents. Despite this there is a sustained reduction in peripheral vascular resistance, and consequently blood pressure, alongside a decrease in cardiac output. It is thought that atenolol's antihypertensive activity may be related to action on the central nervous system (CNS) or it's inhibition of the renin-aldosterone-angiotensin system rather than direct effects on the vasculature.

Atenolol produces CNS effects similar to other beta-blockers, but does so to a lesser extent due to reduces ability to cross the blood-brain barrier. It has the potential to produce fatigue, depression, and sleep disturbances such as nightmares or insomnia. The exact mechanisms behind these have not been characterized but their occurrence must be considered as they represent clinically relevant adverse effects.

Amlopril
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Amlopril
Generic	Amlodipine Besilate + Atenolol
Weight	5mg, 50mg
Type	Tablet
Therapeutic Class
Manufacturer	Halewood Laboratories Pvt Limited
Available Country	India, Nigeria
Last Updated:	September 19, 2023 at 7:00 am

Uses

Essential hypertension: Amlodipine is efficacious as monotherapy in the treatment of hypertension. It may be used in combination with other antihypertensive agents.Angina pectoris: Amlodipine is indicated for the treatment of chronic stable angina pectoris ... Read more

Atenolol is used for: Hypertension, Angina pectoris, Cardiac arrhythmia, Myocardial infarction

Amlopril is also used to associated treatment for these conditions: Alcohol 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 Amlopril works

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 G_s 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 G_q 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

Amlopril dosage

Hypertension: Usual dose is 5 mg once daily. The maximum dose is 10 mg once daily. Elderly patients with hepatic insufficiency may be started on 2.5 mg once daily; this dose may also be used when adding Amlodipine to other antihypertensive therapy.Angina (Chronic stable or Vasospastic): 5 to 10 mg, using the lower dose for elderly and in patients with hepatic insufficiency. Most patients require 10 mg.Administrations: May be taken without regard to meals.

Hypertension: 50 mg once daily, the daily dose can be raised to 100 to 200 mg.

Angina pectoris: 50 to 100 mg daily.

Cardiac arrhythmia: Atenolol in low dose, 25-50 mg once daily, can be used in combination with digoxin to control the ventricular rate in atrial fibration or atrial flutter which is refractory to digoxin alone.

Side Effects

The most common adverse effects of amlodipine are associated with vasodilatory action, such as dizziness, flushing, headache, hypotension and peripheral edema. Gastrointestinal disturbances, increased micturition frequency, lethargy, eye pain and mental depression may also occur. A paradoxical increase in ischaemic chest pain may occur at the start of the treatment and in a few patients excessive fall in blood pressure has led to cerebral or myocardial ischaemia or transient blindness. Rashes, fever and abnormalities in liver function due to hypersensitivity reaction of Amlodipine may occur.

In general, atenolol is well tolerated although in a small number of patients (approximately 2-3%) therapy must be withdrawn because of troublesome symptomatic adverse effects. The commonest of these are cold extrimities, fatigue, vivid dreams, insomnia, diarrhoea, constipation, impotence and paraesthesia. Bronchospasm has been occurred with atenolol although this is very much less common than with the non-selective β-blockers.

Toxicity

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

Precaution should be taken in patients with hepatic impairment and during pregnancy and breast feeding.

Patients already on a β-blocker must be evaluated carefully before Atenolol is administered. Atenolol may aggravate peripheral arterial circulatory disorders. Impaired Renal Function: Caution should be excised.

Interaction

Drug Interactions- Potentially hazardous interactions: Little or no data are available in patients with markedly impaired cardiac left ventricular function; however, as with other calcium antagonist drugs, the combination of Amlodipine and p-blockers should be avoided in such patients. Other Significant Interactions- Digoxin: Absence of any interaction between Amlodipine and Digoxin in healthy volunteers has been documented in a controlled clinical study. Cimetidine: An unpublished clinical study indicated no interaction between, Amlodipine and Cimetidine in healthy volunteers. Warfarin: An unpublished clinical study in healthy volunteers indicates that Amlodipine did not significantly alter the effect of Warfarin on prothrombin time. Food: Food does not alter the rate or extent of absorption of Amlodipine.

Catecholamine-depleting drugs (e.g., Reserpine) and Calcium channel blockers may have an additive effect when given with Atenolol. Clonidine and aspirin may have some drug reactions.

Volume of Distribution

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

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

6-7 hrs.

Clearance

Total clearance is estimated at 97.3-176.3 mL/min with a renal clearance of 95-168 mL/min.

Elimination Route

85% is eliminated by the kidneys following IV administration with 10% appearing in the feces.

Pregnancy & Breastfeeding use

Pregnancy Category C. There are no adequate and well-controlled studies of Amlodipine in pregnant women. Amlodipine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether Amlodipine is excreted in human milk. In the absence of this information, it is recommended that nursing be discontinued while Amlodipine is administered.

Pregnancy Category D. Caution should be exercised when Atenolol is administered to a nursing woman.

Contraindication

Hypersensitivity to dihydropyridine derivatives. Pregnant woman.

Atenolol is contraindicated for: Second and third degree heart block, Untreated heart failure, Overt cardiac failure, Cardiogenic shock.

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

Symptoms: Available data suggest that large overdosage could result in excessive peripheral vasodilatation and possibly reflex tachycardia. Marked and probably prolonged systemic hypotension up to and including shock with fatal outcome have been reported.Management: Clinically significant hypotension due to amlodipine overdosage calls for active cardiovascular support including frequent monitoring of cardiac and respiratory function, elevation of extremities, and attention to circulating fluid volume and urine output. A vasoconstrictor may be helpful in restoring vascular tone and blood pressure, provided that there is no contraindication to its use. Intravenous calcium gluconate may be beneficial in reversing the effects of calcium channel blockade. Gastric lavage may be worthwhile in some cases. In healthy volunteers the use of charcoal up to 2 hours after administration of amlodipine 10 mg has been shown to reduce the absorption rate of amlodipine. Since amlodipine is highly protein-bound, dialysis is not likely to be of benefit.

Overdosage with Atenolol has been reported with patients surviving acute doses as high as 5 gm. One death was reported in a man who may have taken as much as 10 gm acutely.