Nurses’ Guide to Amlodipine

• Amlodipine, sold under Norvasc, is a dihydropyridine calcium channel blocker used to treat angina and hypertension.  
• Amlodipine can interact with strong CYP3A4 inducers. If those types of medication are prescribed with amlodipine, dose adjustments are required.  
• Amlodipine is generally well tolerated. However, in some patients, it can cause swelling and edema.  

Amlodipine, sold under Norvasc, is a dihydropyridine calcium channel blocker used to treat angina and hypertension. Do not confuse amlodipine with amiloride, or Norvasc with Navane or Vascor during administration.  

Amlodipine is commonly used to manage hypertension and coronary artery disease, such as chronic stable angina, vasospastic, Prinzmetal, or variant angina. It dilates the coronary arteries, peripheral arteries, and arterioles. It also decreases total peripheral vascular resistance and blood pressure by vasodilation.   

Amlodipine use is contraindicated in patients hypersensitive to it. Exercise caution in patients with hepatic impairment, hypertrophic cardiomyopathy with outflow tract obstruction, and severe aortic stenosis. 

When given orally, the medication begins to take effect within 30 minutes to one hour, and the duration of action is 24 hours. It is slowly absorbed from the gastrointestinal tract, metabolized in the liver, protein binding is 95% to 98%, and excreted primarily in urine.   

Amlodipine is not removed by hemodialysis. The half-life of the drug is 30 to 50 hours and is increased in the elderly and patients with hepatic cirrhosis. Therefore, dose adjustments are required in these populations, as heavy doses can lead to severe hypotension. 

Drug Interactions with Amlodipine

Amlodipine can interact with strong CYP3A4 inducers, such as rifampin, phenytoin, and carbamazepine, decreasing their effect and concentration in the body. Dose 0adjustments are required if any of these are prescribed with amlodipine.   

Amlodipine can increase the concentration and effects of anti-hepaciviral combination products. It also might increase the concentration of drugs, such as fosphenytoin, lomitapide, phenytoin, and simvastatin.   

St. John’s wort might decrease the concentration or effect of amlodipine, affecting blood pressure management. Yohimbine may also decrease the antihypertensive action of amlodipine. When given with grapefruit juice or products containing grapefruit extracts, the hypotensive effects of amlodipine may be increased.   

Amlodipine may increase hepatic enzyme levels. Therefore, if the patient complains of nausea and vomiting with its therapy, get their liver function tests done promptly.   

Dosage with Indications

Amlodipine is available in 2.5mg, 5mg, and 10mg tablets. It can be given with or without food.   

Hypertension in adults is managed through the oral route. Initially, 5 mg/day is given as a single dose, which can be titrated every seven to 14 days to a maximum of 10 mg/day.   

In the elderly, the dose of amlodipine should be increased gradually with particular attention to their blood pressure, as it can lead to severe hypotension. Give it as a dose of 2.5mg per day that can be titrated every seven to 14 days with a maximum limit of 10 mg per day.   

For the management of hypertension in children aged 6 to 17 years, the dose of amlodipine is 2.5 mg/day to 5 mg/day.   

For the management of coronary artery disease in adults, amlodipine is given 5 to 10 mg per day as a single dose. In elderly with hepatic insufficiency, it is given as 5 mg per day, a single dose.   

In adults and elderly patients with hepatic impairment, the dose of amlodipine for the management of hypertension is 2.5mg per day initially. For angina, it is 5 mg per day initially. In patients with severe hepatic impairment, titrate the dose slowly and monitor blood pressure, as it can lead to severe hypotension because of altered metabolism.   

Side Effects 

Amlodipine is generally well tolerated. However, in some patients, it can cause swelling and edema. Educate your patients and ask them to report any adverse effects.   

Common side effects of amlodipine include peripheral edema, headaches, and flushing. It can sometimes cause palpitations, dizziness, weakness, and unusual fatigue. Rare side effects include chest pain, orthostatic hypotension, and bradycardia.    

Amlodipine overdose can result in excessive peripheral vasodilation that leads to marked hypotension with reflex bradycardia and syncope.   

Nursing Considerations 

Assess the patient’s baseline hepatic and renal functions, blood pressure, and apical pulse before and during therapy.   

With amlodipine therapy, if the patient’s systolic blood pressure drops to 90mm of Hg, hold the drug and contact the physician soon. In bedridden patients, the patient is assessed for peripheral edema behind the medial malleolus and sacral area. Check the patient’s skin for flushing and ask them about headaches and asthenia.  

Educate the patient and their caregivers about the medication and its side effects. Inform them not to discontinue the drug abruptly. Compliance with the therapy regimen is essential to controlling hypertension. Ask the patient not to do tasks that require alertness and motor coordination until a response to the drug is established. Also, tell them not to ingest grapefruit products, as they can affect the metabolism and concentration of the drug.   

The Bottom Line

Amlodipine remains a drug of choice to manage hypertension and angina and is well tolerated. However, it may need to be stopped in some patients because of edema and headache. Ask your patients to take the medicine as directed and report to the healthcare provider if they have any adverse drug reactions.  

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