Besylon

Each film-coated tablet contains: Amlodipine (as besilate) 5 mg & 10 mg, respectively.

Pharmacology: Pharmacodynamics: Mechanism of Action: Amlodipine is a dihydropyridine calcium-channel blocker. It is a peripheral and coronary vasodilator but unlike the calcium-channel blockers Verapamil or Diltiazem, has little or no effect on cardiac conduction and negative inotropic activity is rarely seen at therapeutic doses. Administration results primarily in vasodilation, with reduced peripheral resistance, blood pressure and afterload, increased coronary blood flow and a reflex increase in heart rate. This in turn results in an increase in myocardial oxygen supply and cardiac output. It has no antiarrhythmic activity. Amlodipine maybe even more selective than Nifedipine for vascular smooth muscle. Most of the dihydropyridine calcium-channel blockers are chiral compounds used as racemic mixtures.
Pharmacokinetics: Amlodipine is well absorbed following oral administration with peak blood concentrations occurring after 6 to 12 hours. The bioavailability is about 60 to 65%. Amlodipine is reported to be about 97.5% bound to plasma proteins. It has a prolonged terminal elimination half-life of 35 to 50 hours and steady-state plasma concentrations are not achieved until after 7 to 8 days of administration. Amlodipine is extensively metabolized in the liver; metabolites are mostly excreted in urine together with less than 10% of a dose as unchanged drug.

Amlodipine is used in the management of hypertension and prophylaxis of angina pectoris.

Hypertension: usual initial dose is 5 mg once daily. Increased if necessary to 10 mg once daily. Similar doses are given in the treatment of stable angina and Prinzmetal's angina or as prescribed by the physician.

Overdosage may be associated with bradycardia and hypotension.

Patients with renal failure: Amlodipine may be used in such patients at normal doses. Changes in Amlodipine plasma concentrations are not correlated with degree of renal impairment. Amlodipine is not dialyzable.
Patients with Impaired Hepatic Function: As with all calcium antagonists, amlodipine half-life is prolonged in patients with impaired liver function and dosage recommendations have not been established.
Use in Pregnancy & Lactation: Safety of Amlodipine in human pregnancy or lactation has not been established. Amlodipine does not demonstrate toxicity in animal reproductive studies other than to delay parturition and prolong labor in rats at a dose level 50 times the maximum recommended dose in humans. Accordingly, use in pregnancy is only recommended when there is no safer alternative and when the disease itself carries greater risk for the mother and fetus.
Use in Elderly: Normal dosage regimens are recommended. Amlodipine, used at similar doses in elderly or younger patients is equally well tolerated.

Amlodipine should be used with caution in patients with hypotension, in patients whose cardiac reserve is poor and in those with heart failure since deterioration of heart failure has been noted. It should not be used in cardiogenic shock, in patients who have recently suffered a myocardial infarction or in acute unstable angina. It should not be used to treat an anginal attack in chronic stable angina. In patients with severe aortic stenosis it may increase the risk of developing heart failure. Sudden withdrawal might be associated with an exacerbation of angina. The dose may need to be reduced in patients with hepatic impairment. It should be discontinued in patients who experience ischemic pain following its administration.

Use in Pregnancy & Lactation: Safety of Amlodipine in human pregnancy or lactation has not been established. Amlodipine does not demonstrate toxicity in animal reproductive studies other than to delay parturition and prolong labor in rats at a dose level 50 times the maximum recommended dose in humans. Accordingly, use in pregnancy is only recommended when there is no safer alternative and when the disease itself carries greater risk for the mother and fetus.

The most common adverse effects are associated with its vasodilator action and often diminish on continued therapy. They include dizziness, flushing, headache, hypotension, peripheral edema, tachycardia and palpitations. Nausea and other gastrointestinal disturbances, increased micturition frequency, lethargy, eye pain and mental depression have also occurred. A paradoxical increase in ischemic chest pain may occur at the start of treatment and in a few patients excessive fall in blood pressure has led to cerebral or myocardial ischemia or transient blindness.
There have been reports of rashes (including erythema multiforme), fever, and abnormalities in liver function, including cholestasis, due to hypersensitivity reactions. Gingival hyperplasia, myalgia, tremor and impotence have been reported.

May enhance the antihypertensive effects of other antihypertensive drugs such as beta blockers although the combination is generally well tolerated. Enhanced antihypertensive effects may also be seen with concomitant use of drugs such as aldesleukin and antipsychotics that cause hypotension. Nifedipine may modify insulin and glucose responses and therefore diabetic patients may need to adjust their antidiabetic treatment when receiving amlodipine. It is extensively metabolized in the liver by the cytochrome P450 enzyme system, and interactions may occur with other drugs such as quinidine sharing the same metabolic pathway and with enzyme inducers such as carbamazepine, phenytoin and rifampicin and enzyme inhibitors such as cimetidine and erythromycin.

Store at temperatures not exceeding 30°C.
Store in airtight containers. Protect from light.

Calcium Antagonists / Anti-Anginal Drugs

C08CA01 - amlodipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.

Rx