What Is Norvasc?
Norvasc is also used to treat coronary artery disease (CAD) in patients without heart failure, and certain types of angina (chest pain) from CAD, such as activity- and stress-induced angina (chronic stable angina), and angina that occurs at rest (Prinzmetal’s angina).
Taken regularly, Norvasc can control angina, but it doesn't stop chest pain after it has already begun.
The drug can also lower a person's risk of cardiovascular events related to high blood pressure, such as strokes and heart attacks.
Norvasc belongs to a class of drugs called calcium channel blockers, which block the flow of calcium into heart muscles and the muscles along the walls of blood vessels.
Because the contraction of these muscles depends on calcium, Norvasc relaxes and widens blood vessels, thereby improving blood flow.
Doctors also sometimes prescribe Norvasc "off-label" for the treatment of cluster headaches, migraines, Raynaud's syndrome (a blood vessel disorder), and congestive heart failure.
Manufactured by Pfizer, Norvasc was first approved by the Food and Drug Administration (FDA) in 1987.
In the early 1990s, researchers conducted the so-called PRAISE study, which was backed by Pfizer, to determine if Norvasc could help reduce the risk of death in people with severe heart failure.
Though the study found little overall benefits to severe heart failure patients, it suggested that Norvasc might prolong the life of a subgroup of people with heart failure from non-ischemic cardiomyopathy (cardiac muscle damage not associated with low blood supply to the coronary arteries).
To investigate this possibility, Pfizer-sponsored the PRAISE-2 study, which found no benefit to the subgroup in the PRAISE-1 trial and was presented at a conference in 2000.
However, results of the study weren't published in an academic journal until 2013, leading some experts to question whether Pfizer intentionally delayed publication to prevent the data and findings from being publicly available.
Norvasc Warnings
People with a known sensitivity to amlodipine should not take Norvasc.Though Norvasc is used to treat angina, worsening chest pain and heart attacks can develop after starting or increasing your dose of the drug — this is especially true for people with severe obstructive coronary artery disease.
Norvasc can also cause symptomatic hypotension (low blood pressure), particularly in people with a heart valve problem called severe aortic stenosis.
Before starting Norvasc, let your doctor know if you ever had heart disease or liver problems, as you may require a different course of Norvasc treatment.
Pregnancy and Norvasc
Norvasc poses a possible hazard to unborn infants.Animal studies have shown that amlodipinebesylate increases the risk of death of fetuses in utero, decreases litter size, and prolongs both pregnancy and labor duration, but there have been no adequate and well-controlled studies in pregnant women.
The drug should therefore only be used during pregnancy if the benefits to the mother outweigh the risks to the unborn child.
Women who are breastfeeding should not use Norvasc because it's unknown if the drug is excreted in breast milk.
Norvasc Side Effects
Common Side Effects of Norvasc
The most common side effect of Norvasc is edema, or swelling of the hands, feet, ankles, or lower legs. You are more likely to experience edema with higher doses of Norvasc. Other common side effects of Norvascinclude:- Headache
- Abdominal pain
- Nausea
- Dizziness
- Drowsiness and fatigue
- Flushing (feeling of warmth)
Severe Side Effects of Norvasc
Taking Norvasc can result in several serious side effects. Seek medical help immediately if you experience:- More frequent or severe chest pain
- Palpitations (rapid, strong, or irregular heartbeats)
- Fainting
Rare Side Effects of Norvasc
In clinical trials, Norvasc has been associated with numerous rare side effects, which affect less than one percent of people. These include, but are not limited to:- Muscle cramps
- Diarrhea, vomiting, and weight changes
- Abnormal vision
- Depression and anxiety
- Itchiness and rashes
- Difficulty breathing
Norvasc Interactions
- Inhibitors of the liver enzyme CYP3A4, including ketoconazole (Nizoral, Extina), itraconazole (Sporanox), and ritonavir (Norvir)
- Sildenafil (Viagra)
- Cyclosporine (Restasis, Neoral)
Norvasc Dosage
Adults typically start out with a 5 mg dose, with a maximum dose of 10 mg. Adults who are small, fragile, elderly, or have liver problems may be started on a 2.5 mg dose.
Children ages 6 to 17 may be given doses of 2.5 to 5 mg — a daily dose of over 5 mg has not been studied in children. The effect of Norvasc on children under 6 years old is unknown.
Norvasc Overdose
Norvasc overdose can result in rapid heartbeat and severe hypotension, possibly resulting in dizziness and fainting. If you believe you've overdosed, call your local poison control center, or go to the nearest hospital emergency room immediately. If someone taking Norvasc has collapsed or is not breathing, call 911.Missed Dose of Norvasc
Take your dose of Norvasc at the same time every day. If you miss a dose of Norvasc, take it as soon as you remember. If has been more than 12 hours since your missed dose, wait and take your next dose at your normal time.Norvasc Pictures
