Amlodipine

What is Amlodipine?

Amlodipine is a prescription medication that belongs to a class of drugs called calcium channel blockers, specifically the dihydropyridine subclass. It is primarily used to treat high blood pressure (hypertension) and certain types of chest pain (angina). This medication works by relaxing blood vessels, making it easier for the heart to pump blood throughout the body.

Uses

Amlodipine is approved for several cardiovascular conditions:

• Hypertension: The most common use, helping to lower blood pressure and reduce the risk of heart attack, stroke, and kidney problems
• Chronic stable angina: Reduces chest pain caused by reduced blood flow to the heart muscle during physical activity or stress
• Vasospastic angina (Prinzmetal’s angina): Treats chest pain caused by coronary artery spasms
• Coronary artery disease: May be used as part of a comprehensive treatment plan to improve blood flow to the heart
• Combination therapy: Often prescribed alongside other blood pressure medications like ACE inhibitors or diuretics for better blood pressure control

How it works

Amlodipine blocks calcium channels in the smooth muscle cells of blood vessels and the heart. By preventing calcium from entering these cells, the medication causes blood vessels to relax and widen, reducing the pressure against which the heart must pump. This mechanism also reduces the heart’s workload and oxygen demand, which helps prevent chest pain in people with angina.

Side effects

Common side effects include:

Submit Your Paper

• Swelling of ankles, feet, or hands (peripheral edema)
• Dizziness or lightheadedness
• Fatigue or tiredness
• Flushing or feeling warm
• Headache
• Nausea
• Abdominal pain
• Drowsiness

Serious side effects that require immediate medical attention:

• Severe dizziness or fainting
• Irregular or rapid heartbeat
• Severe swelling of face, lips, tongue, or throat
• Chest pain that worsens or doesn’t improve
• Severe skin reactions or rash

Warnings and precautions

• Liver disease: Patients with severe liver problems may need dosage adjustments, as amlodipine is metabolized by the liver
• Heart conditions: Use caution in patients with severe aortic stenosis or heart failure, as the medication can worsen these conditions
• Pregnancy and breastfeeding: Amlodipine is classified as pregnancy category C; use only if potential benefits outweigh risks. It’s unknown if the drug passes into breast milk
• Elderly patients: Older adults may be more sensitive to side effects and may require lower starting doses
• Sudden discontinuation: Do not stop taking amlodipine suddenly without consulting your doctor, as this may worsen chest pain or cause blood pressure to spike

Interactions

• Simvastatin: Amlodipine can increase simvastatin levels, raising the risk of muscle problems; simvastatin dose should be limited
• CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir): These can increase amlodipine levels and enhance its blood pressure-lowering effects
• CYP3A4 inducers (rifampin, St. John’s wort): May decrease amlodipine effectiveness by increasing its metabolism
• Other blood pressure medications: Combined use may cause excessive blood pressure reduction and increased risk of dizziness
• Grapefruit juice: Can increase amlodipine blood levels, potentially enhancing side effects
• Cyclosporine: Amlodipine may increase cyclosporine levels, requiring dose monitoring
• Tacrolimus: Similar to cyclosporine, blood levels may increase when used with amlodipine
• Sildenafil and other PDE5 inhibitors: May cause significant blood pressure drops when combined

Check interactions with the GMJ Interaction Checker

Dosage

For adults with hypertension, the typical starting dose is 5 mg once daily, which may be increased to a maximum of 10 mg once daily based on blood pressure response. For angina, the usual dose ranges from 5-10 mg once daily. Elderly patients or those with liver problems typically start with 2.5 mg once daily. Amlodipine can be taken with or without food, and it’s important to take it at the same time each day for consistent blood levels. Dosage adjustments should always be made under the guidance of a healthcare provider based on individual response and tolerability.

Sources: FDA DailyMed drug labels (public domain), BNF, WHO Essential Medicines List. This article is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before starting or stopping any medication.

This work is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0). You are free to share and adapt this content with attribution to GMJ News (news.gmj.ge).