Amlodipine: Uses,Dosage,Side Effects

Generic Name
Amlodipine 5mg, 10 mg Tablet
Calcium-channel blockers

Pharmacology :
Amlodipine may be a long-acting calcium channel blocker that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and heart muscle. Thus it causes a reduction in peripheral vascular resistance and contractile process in heart muscle and reduces vital sign.

The mechanism of the antihypertensive action is thanks to an immediate relaxant effect on vascular smooth muscle. The precise mechanism by which amlodipine relieves angina has not been fully determined but Amlodipine reduces the total ischemic burden by the subsequent two actions:

Amlodipine dilates peripheral arterioles and thus, reduces the entire peripheral resistance (afterload) against which the guts works. Since the guts rate remains stable, this unloading of the guts reduces myocardial energy consumption and oxygen requirements.

The mechanism of action of Amlodipine also probably involves dilatation of most coronary arteries and coronary arterioles, both in normal and ischemic regions. This dilation increases myocardial oxygen delivery in patients with arteria coronaria spasm (prinzmetals or variant angina).

Indications :
Amlodipine may be a calcium channel blocker and should be used alone or together with other antihypertensive and antianginal agents for the treatment of Hypertension and arteria coronaria Disease (such as Chronic Stable Angina, Vasospastic Angina and Angiographically Documented arteria coronaria Disease in patients without coronary failure or an ejection fraction < 40%).

Dosage & Administration :
Adult: Starting dose Amlodipine 5 mg Tablet once daily with maximum dose Amlodipine 10 mg tablet once daily.
Pediatric: Starting dose Amlodipine 2.5 mg tablet to five mg once daily.
Small, Fragile and Elderly patients or patients with hepatic insufficiency: Starting dose 2.5 mg once daily.

Interaction :
Amlodipine has been safely administered with thiazide diuretics, alpha-blockers, beta-blockers, angiotensin-converting enzyme inhibitors, long-acting nitrates, sublingual nitroglycerine, non-steroidal anti-inflammatory drugs, antibiotics, and oral hypoglycemic drugs. Amlodipine has no effect on protein binding of digoxin, phenytoin, warfarin, or indomethacin. Administration of Amlodipine with grapefruit or fruit juice isn't recommended as bioavailability could also be increased in some patients leading to increased vital sign lowering effects.

Contraindications :
It is contraindicated in patients with known sensitivity to Amlodipine.

Side Effects :
The most common side effects are headache and oedema which occurred during a dose-related manner. Other side effects not dose-related but reported with an incidence >1.0% are headache, fatigue, nausea, abdominal pain and somnolence.

Pregnancy & Lactation :
Pregnancy Category C. There are not any adequate and well-controlled studies of Amlodipine in pregnant women. Amlodipine should be used during pregnancy as long as the potential benefit justifies the potential risk to the fetus. it's not known whether amlodipine is excreted in human milk. within the absence of this information, it's recommended that nursing be discontinued while Amlodipine is run.

Precautions & Warnings :
Symptomatic hypotension is feasible, particularly in patients with severe stenosis. However, due to the gradual onset of action, acute hypotension is unlikely. Worsening angina and acute myocardial infarct can develop after starting or increasing the dose of Amlodipine, particularly in patients with severe obstructive arteria coronaria disease. Titrate slowly when administering calcium channel blockers to patients with severe hepatic impairment.

Use in Special Populations :

Children with hypertension from 6 years to 17 years of age: 2.5 mg once daily as a starting dose, up-titrated to five mg once daily if vital sign goal isn't achieved after 4 weeks. Doses in more than 5 mg daily haven't been studied in pediatric patients.
Children under 6 years old: The effect of amlodipine on a vital sign in patients but 6 years aged isn't known.

Elderly: Amlodipine used at similar doses in elderly or younger patients is equally well tolerated. Normal dosage regimens are recommended within the elderly, but an increase of the dosage should happen with care.
Renal impairment: Changes in amlodipine plasma concentrations aren't correlated with the degree of renal impairment, therefore the traditional dosage is suggested. Amlodipine isn't dialysable.

Hepatic impairment: Dosage recommendations haven't been established in patients with mild to moderate hepatic impairment; therefore dose selection should be cautious and will start at the lower end of the dosing range. The pharmacokinetics of Amlodipine hasn't been studied in severe hepatic impairment. Amlodipine should be initiated at rock bottom dose (2.5 mg once daily) and titrated slowly in patients with severe hepatic impairment.

Overdose :
In humans, experience with intentional overdose is restricted.
Symptoms: Available data suggest that enormous overdosage could end in excessive peripheral vasodilatation and possibly a reflex tachycardia. Marked and doubtless prolonged systemic hypotension up to and including shock with the fatal outcome are reported.
Management: Clinically significant hypotension thanks to amlodipine overdosage involves active cardiovascular support including frequent monitoring of cardiac and respiratory function, the elevation of extremities, and a spotlight to circulating fluid volume and urine output. 
A vasoconstrictor could also be helpful in restoring vascular tone and vital sign, as long as there's no contraindication to its use. Intravenous calcium gluconate could also be beneficial in reversing the consequences of calcium channel blockade. lavage could also be worthwhile in some cases. In healthy volunteers, the utilization of charcoal up to 2 hours after administration of amlodipine 10 mg has been shown to scale back the absorption rate of amlodipine. Since amlodipine is very protein-bound, dialysis isn't likely to be of benefit.

Storage :
keep in a dry place far away from light and warmth. exclude of the reach of children.

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