Lisinopril and Amlodipine are two commonly prescribed medications for managing high blood pressure. While both aim to lower blood pressure, they belong to different drug classes and work in distinct ways. This article clarifies these differences.
How They Work: Mechanisms of Action
Lisinopril operates as an Angiotensin-Converting Enzyme (ACE) inhibitor, a class of medications that primarily target the renin-angiotensin-aldosterone system (RAAS). It functions by blocking the action of the angiotensin-converting enzyme, which is responsible for converting angiotensin I into angiotensin II. Angiotensin II is a powerful substance that narrows blood vessels and stimulates fluid retention, both of which increase blood pressure. By preventing its formation, Lisinopril leads to the widening of blood vessels (vasodilation) and helps the body excrete excess fluid and sodium, lowering blood pressure.
Amlodipine is classified as a calcium channel blocker (CCB), specifically a dihydropyridine type. Amlodipine works by inhibiting the influx of calcium ions into heart and blood vessel cells. Calcium ions play a role in muscle contraction, so preventing their entry relaxes and widens blood vessels, particularly the arteries. This vasodilation reduces the resistance against which the heart must pump, decreasing blood pressure and a reduced workload for the heart.
Conditions They Treat
Lisinopril is primarily prescribed for the management of hypertension. Beyond its use in hypertension, it also plays a role in treating heart failure, a condition where the heart cannot pump enough blood to meet the body’s needs. Lisinopril is also used to improve survival rates after a heart attack, helping to protect the heart muscle from further damage.
Amlodipine is widely used to treat hypertension. It is also commonly prescribed for angina, which is chest pain caused by reduced blood flow to the heart. Amlodipine helps to alleviate angina symptoms by improving blood and oxygen supply to the heart muscle.
Side Effects and Important Warnings
Lisinopril can cause side effects. A common side effect is a persistent dry cough, which may lead to discontinuation. Other common effects include dizziness and fatigue, often due to the lowering of blood pressure. More serious, less frequent side effects include angioedema (severe swelling of the face, lips, tongue, or throat) and potential kidney problems. Lisinopril is not recommended during pregnancy, particularly in the second and third trimesters, as it can harm the developing fetus’s kidneys and overall development.
Amlodipine also has potential side effects. Swelling in the ankles or feet (edema) is a common side effect due to its effect on blood vessels. Other common effects include headache, flushing, and dizziness. Serious side effects can include excessively low blood pressure or, rarely, a worsening of chest pain, especially when treatment begins or dosage increases.
Both medications can cause dizziness, particularly when standing up quickly, as a result of their blood pressure-lowering effects. Individual responses to these medications can vary, so discuss any side effects or concerns with a healthcare professional.
Who Might Take Which: Patient Considerations
The decision between Lisinopril or Amlodipine involves assessing a patient’s overall health and specific medical conditions. A healthcare provider considers co-existing medical conditions; for example, a patient with heart failure or who has recently experienced a heart attack might be better suited for Lisinopril due to its specific benefits in these areas. Conversely, Amlodipine may be a more appropriate choice for individuals experiencing angina in addition to high blood pressure.
Other medications a patient takes are also important, as drug interactions can influence the choice. Individual responses to treatment, including blood pressure control and side effects, guide medication selection and adjustments. For example, a patient with a history of the dry cough associated with ACE inhibitors might be steered away from Lisinopril. The selection of either medication is a medical decision by a healthcare professional after a thorough evaluation of the patient’s health profile.