Amlodipine – Overview

What is amlodipine?

Amlodipine, initially approved by the FDA in 1987, is a popular antihypertensive drug belonging to the group of drugs called dihydropyridine calcium channel blockers. Due to their selectivity for the peripheral blood vessels, dihydropyridine calcium channel blockers are associated with a lower incidence of myocardial depression and cardiac conduction abnormalities than other calcium channel blockers.

Amlodipine is commonly used in the treatment of high blood pressure and angina. It has antioxidant properties and an ability to enhance the production of nitric oxide (NO), an important vasodilator that decreases blood pressure. The option for single daily dosing of amlodipine is an attractive feature of this drug.

Brand Names

Amlobenz, Azor, Caduet, Dafiro, Exforge, Exforge Hct, Katerzia, Lotrel, Norliqva, Norvasc, Prestalia, Tribenzor, Twynsta, Viacoram

What is the proper storage of amlodipine?

This drug must be stored at the right temperature: Store amlodipine at room temperature between 59°F and 86°F (15°C and 30°C). Store this drug in its original container and keep it tightly closed. Keep this drug away from light.

Identity of Amlodipine

Type of medicine	Antihypertensive
Synonyms	Amlodipine, Amlodipino, Amlodipinum
Molecular Formula	C20H25ClN2O5
Molecular Weight	408.876 g/mol
IUPAC Names	(RS)-3-ethyl 5-methyl 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate
Structural formula of main components
Pure active ingredient	Amlodipine Besilate
Appearance	White crystalline powder
Melting point	199-201°C
Available as	Tablet and Capsule
Prescription	Prescription Required

What is amlodipine used for?

Amlodipine, also known as Amvaz, Katerzia, and Norvasc, is a cardiovascular medication used to lower blood pressure in individuals with high blood pressure (hypertension) and to help relieve symptoms of chest pain.

Amlodipine side effects

Amlodipine’s possible side effects are described below.

More common side effects

The more common side effects that can occur with include:

• Swelling of your legs or ankles
• Tiredness
• Feeling sleepy
• Abdominal pain
• Nausea
• Dizziness
• Hot or warm feeling in your face (flushing)
• Very fast heart rate (palpitations)

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Serious side effects and their symptoms can include the following:

• Low blood pressure. Symptoms can include:
  • Severe dizziness
  • Lightheadedness
  • Fainting
• More chest pain or a heart attack. In rare cases, when you first start taking amlodipine or increase your dosage, your chest pain may get worse or you may have a heart attack. Symptoms can include:
  • Chest pain or discomfort
  • Upper body discomfort
  • Shortness of breath
  • Breaking out in a cold sweat
  • Unusual tiredness
  • Nausea
  • Lightheadedness

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. It 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 Label. 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.

What other drugs will affect amlodipine?

Tell your doctor about all your current medicines and any you start or stop using, especially:

• Nitroglycerin;
• Simvastatin (Zocor, Simcor, Vytorin); or
• Any other heart or blood pressure medications

This list is not complete. Other drugs may interact with amlodipine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Dosage and Administration

Dosages of Amlodipine

Dosages of Amlodipine should be given as follows:

Adult and Pediatric Dosage Forms & Strengths

Tablets: 2.5 mg, 5 mg, and 10 mg

Dosage Considerations

Hypertension (High Blood Pressure)

• Adult: 5 mg/day orally initially; may be increased by 2.5 mg/day every 7-14 days; not to exceed 10 mg/day orally; maintenance: 5-10 mg/day orally
• Pediatric: Children under 6 years: Safety and efficacy not established
• Children 6 years and older: 2.5-5 mg/day orally
• Geriatric: 2.5-5 mg/day orally initially; may be increased by 2.5 mg/day every 7-14 days; not to exceed 10 mg/day orally; maintenance: 5-10 mg/day orally

Coronary Artery Disease

Treatment of chronic stable angina and vasospastic angina (Prinzmetal or variant angina) and angiographically documented coronary artery disease (CAD) in patients without heart failure or ejection fraction (EF) less than 40%

• Adult: 5-10 mg/day orally initially; maintenance: 10 mg/day orally
• Geriatric: 2.5-10 mg/day orally initially; maintenance: 10 mg/day orally

Angina

• Adult: 5-10 mg/day orally; maintenance: 10 mg/day orally
• Geriatric: 2.5-10 mg/day orally; maintenance: 10 mg/day

Dosage Modifications

• Hepatic insufficiency: Consider starting with 2.5 mg/day orally
• Severe hepatic impairment: Titrate slowly

Dosing Considerations

Also given in combination with benazepril (Lotrel), atorvastatin (Caduet), olmesartan (Azor), telmisartan (Twynsta), and valsartan (Exforge)

• Geriatric: Start dosing at the low end of the dosing range; elderly patients have a greater frequency of decreased renal, hepatic or cardiac function

What are the symptoms of amlodipine overdose?

The effects of an overdose on amlodipine include excessive relaxation of blood vessels with possible dangerous lowering of blood pressure and increased heart rate. Overdose may also lead to shock and acute kidney failure.

Precautions

Before taking amlodipine, tell your doctor or pharmacist if you are allergic to it; or to other dihydropyridine calcium channel blockers (such as nisoldipine, nifedipine) or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: a certain structural heart problem (aortic stenosis), very low blood pressure, liver disease.

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you dizzier. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, non-prescription drugs, and herbal products).

Older adults may be more sensitive to the effects of this drug, especially dizziness.

Pregnancy, breastfeeding and fertility while taking amlodipine

Amlodipine and pregnancy

Amlodipine can be used in pregnancy. Although there is not a lot of information on its safety, it is not thought to be harmful to the baby.

If you are pregnant, or planning a pregnancy, talk to your doctor about it. They may wish to change amlodipine for a medicine that has more safety information. However, if your blood pressure levels are OK, then it may be better to continue taking it rather than switching to another medicine.

Amlodipine and breastfeeding

If your doctor or health visitor says your baby is healthy, it’s OK to take amlodipine while you’re breastfeeding, but talk to your doctor or pharmacist as they may recommend a medicine we know more about, like nifedipine. Amlodipine passes into breast milk in small amounts and has not been known to cause side effects in breastfed babies.

If you notice that your baby is not feeding as well as usual, seems unusually sleepy, looks much paler than usual or if you have any other concerns about your baby, then talk to your health visitor, midwife, pharmacist or doctor as soon as possible.

Amlodipine and fertility

There’s no evidence to suggest that taking amlodipine reduces fertility in women.

Amlodipine may affect sperm function. Speak to your doctor if you are having difficulty trying for a baby, as stopping it may be considered. Talk to your fertility specialist if you’re worried.