Amlodipine Besylate| calcium channel blocker

Amlodipine besylate is the besylate salt of amlodipine, a long-acting calcium channel blocker. Amlodipine besylate is chemically described as 3-Ethyl-5-methyl (±)-2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl)-1, 4-dihydro-6-methyl-3, 5-pyridinedicarboxylate, monobenzenesulphonate. Its empirical formula is C20H25CIN2O5•C6H6O3S
Amlodipine belongs to a group of medicines called calcium antagonists


Amlodipine besylate is a white crystalline powder with a molecular weight of 567.1. It is slightly soluble in water and sparingly soluble in ethanol. Amlodipine besylate tablets are formulated as white tablets equivalent to 2.5, 5 and 10 mg of amlodipine for oral administration. In addition to the active ingredient, amlodipine besylate, each tablet contains the following inactive ingredients: microcrystalline cellulose, dibasic calcium phosphate anhydrous, sodium starch glycolate, and magnesium stearate.

 Amlodipine tablets contain the active substance amlodipine besylate. Amlodipine belongs to a group of medicines called calcium antagonists. It is used to treat:
• Angina pectoris (pain in the chest caused by blockages in the arteries leading to the heart) or chest pain classed as vasospastic angina pectoris (or Prinzmetal’s angina).




In patients with high blood pressure, your medicine works by relaxing blood vessels, so that blood passes through them more easily. In patients with angina, Amlodipine tablets work by improving blood supply to the heart muscle, which then receives more oxygen, and as a result chest pain is prevented. Your medicine does not provide immediate relief of chest pain from angina.

Mechanism of Action

Amlodipine is a dihydropyridine calcium antagonist (calcium ion antagonist or slow-channel blocker) that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. Experimental data suggest that amlodipine binds to both dihydropyridine and non-dihydropyridine 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. The precise mechanisms by which amlodipine relieves angina have not been fully delineated, but are thought to include the following:

Exertional Angina: In patients with exertional angina, amlodipine reduces the total peripheral resistance (afterload) against which the heart works and reduces the rate pressure product, and thus myocardial oxygen demand, at any given level of exercise.

Vasospastic Angina: Amlodipine has been demonstrated to block constriction and restore blood flow in coronary arteries and arterioles in response to calcium, potassium epinephrine, serotonin, and thromboxane A2 analog in experimental animal models and in human coronary vessels in vitro. This inhibition of coronary spasm is responsible for the effectiveness of amlodipine in vasospastic (Prinzmetal’s or variant) angina.

Amlodipine tablets with food and drink

Grapefruit juice and grapefruit should not be consumed by people who are taking Amlodipine tablets. This is because grapefruit and grapefruit juice can lead to an increase in the blood levels of the active ingredient amlodipine, which can cause an unpredictable increase in the blood pressure lowering effect of Amlodipine tablets.

Pregnancy and breast-feeding

Pregnancy The safety of Amlodipine in human pregnancy has not been established. If you are pregnant, think you might be pregnant, or are planning to get pregnant, you must tell your doctor before you take Amlodipine tablets.
Breast-feeding Amlodipine has been shown to pass into breast milk in small amounts. If you are breast-feeding or about to start breast-feeding you must tell your doctor before taking Amlodipine tablets.

Driving and using machines

Amlodipine tablets may cause dizziness, headaches, tiredness or feeling sick. Any of these side effects would reduce your ability to react; do not drive or use machinery if you are affected.

How to take Amlodipine tablets
Always take this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure.

The recommended dose is:
• Adults (including the elderly and children 18 years or over): 5mg once a day, up to a maximum of 10mg a day as a single dose depending on your response. If you are elderly, your doctor will closely monitor your response to any dose increase.
• Use in Children and adolescents (6 -17 years old): the recommended usual starting dose is 2.5mg a day. The maximum recommended dose is 5mg a day. Amlodipine 2.5mg is not currently available and the 2.5mg dose cannot be obtained with Amlodipine tablets 5mg as these tablets are not manufactured to break into two equal halves.
• Patients with impaired liver function: your doctor may prescribe you a different dose.




Reference
https://www.webmd.com/drugs/2/drug-5891/amlodipine-oral/details
https://www.rxlist.com/norvasc-drug.htm
https://www.rxlist.com/norvasc-side-effects-drug-center.htm
https://www.drugs.com/amlodipine.html
https://www.medicalnewstoday.com/articles/amlodipine-oral-tablet
https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=fc7d39d7-e006-4ed6-a31c-827452603002&type=display
https://www.medicinenet.com/amlodipine/article.htm

Post a comment

0 Comments