How Does Lisinopril Protect Kidneys?
Lisinopril is a prescription medication commonly used to treat hypertension (high blood pressure) and heart failure. It is also used to treat acute myocardial infarction (heart attack) along with other drugs and has been found to increase the chances of survival in such patients. Lisinopril is available in generic form as well as under the brand names Zestril and Prinivil. The generic version costs less but may not be available in all the strengths and formulations as the brand-name drugs.
Lisinopril belongs to a class of medications called angiotensin-converting enzyme or ACE inhibitors. Another medicine in this drug class is enalapril (Vasotec). Please continue reading to learn more about how lisinopril works and the effects it has on the kidneys.
What is an ACE inhibitor? How does it work?
An ACE inhibitor, as its name indicates, works by inhibiting the angiotensin-converting enzyme, thus, preventing the conversion of angiotensin I to angiotensin II. Angiotensin II is an enzyme that is responsible for causing the smooth muscles of blood vessels to contract, thereby raising blood pressure. Hence, when an ACE inhibitor like lisinopril blocks the production of angiotensin II, relaxation of the blood vessels occurs, leading to a decrease in blood pressure. Regarding heart failure patients, ACE inhibitors make it easier for the heart to pump blood. Studies have shown that people treated with an ACE inhibitor after a heart attack survive longer than those who do not receive this class of drugs.
How do ACE inhibitors protect the kidneys?
From the above paragraphs, it would appear that all of the actions of lisinopril are on the heart and circulation—it reduces blood pressure and decreases the heart’s workload. However, lisinopril has a surprising benefit for the kidneys. For patients with diabetes and high blood pressure, lisinopril treatment can prevent the progression of kidney disease.
The beneficial effects of ACE inhibitors on the kidneys are multifactorial. For example, uncontrolled hypertension or high blood pressure can, over time, cause the arteries that supply blood to the kidneys to harden and become damaged. As a result, the renal tissue does not get enough blood, resulting in deprivation of oxygen and essential nutrients in the kidneys, which can lead to kidney damage, and eventually kidney failure—a condition when the kidneys lose their ability to filter blood and eliminate waste. By controlling high blood pressure, ACE inhibitors like lisinopril help protect against kidney disease and kidney failure.
It is worth noting that one of the numerous functions of the kidneys is to regulate blood pressure. When the kidneys are damaged, it leads to high blood pressure. This becomes a vicious cycle--high blood pressure damages the kidneys, and damaged kidneys lead to high blood pressure. Without appropriate treatment, this negative spiral can lead to kidney failure.
Another protective effect of lisinopril on the kidneys is a reduction in proteinuria. Proteinuria is the presence of protein in the urine. This is a sign of kidney disease. The presence of protein in the urine indicates that the kidneys are not doing their job well and allow proteins to escape through the renal tissue filters into the urine. ACE inhibitors effectively reduce proteinuria while controlling blood pressure, both of which are beneficial for the kidneys.
Is lisinopril used to treat high blood pressure?
Yes, lisinopril and other ACE inhibitors such as enalapril are indicated for the treatment of high blood pressure and heart failure. They are also first-line treatment of hypertension for patients with diabetes. As noted, lisinopril relaxes the blood vessels and reduces blood pressure. Studies have shown that a few weeks of treatment with this medication can significantly bring down blood pressure readings. However, some patients do not respond to lisinopril alone. In such individuals, the doctor may prescribe other drugs in combination with the ACE inhibitor.
What effect does lisinopril have on the kidneys?
As noted above, lisinopril and other ACE inhibitors reduce blood pressure and ensure that the kidneys continue to receive a healthy blood supply. Therefore, lisinopril has primarily beneficial effects on the kidneys, however, like most medications, lisinopril can also have unwanted effects. For example, it can lead to a rise in blood potassium levels by decreasing the amount of potassium excreted through the kidneys. For this reason, your doctor may advise periodic checks of blood potassium levels and kidney function if you are being treated with ACE inhibitors.
What are the side effects of ACE inhibitors?
Common side effects of angiotensin-converting enzyme or ACE inhibitors include cough, headache, dizziness, chest pain, and low blood pressure. More serious side effects include angioedema, sudden swelling of the face, tongue, and throat, which can potentially be fatal. As noted, ACE inhibitor therapy can also lead to high blood potassium levels, leading to dangerous heart arrhythmias (irregular heart rhythm). Other rare but possible adverse effects of ACE inhibitors are kidney problems and liver failure.
How does lisinopril cause and prevent renal failure?
When taken as prescribed by a healthcare provider, ACE inhibitors are relatively safe medications. They prevent renal failure by protecting the kidneys against high blood pressure and reducing proteinuria.
However, when taken along with other blood pressure medications, ACE inhibitors can potentially increase the risk of kidney failure due to drug interactions. This is because a combination of blood pressure medicines can lead to low blood pressure, high blood potassium levels, and other complications, including kidney failure. It is important to know that ACE inhibitors are indicated for the general adult population, however, the use of this drug class is contraindicated with pregnancy and lactation as fetal risks have been demonstrated.
It is imperative to seek timely treatment for high blood pressure. Lisinopril and other ACE inhibitors like enalapril are just one of the many classes of drugs that can be used to accomplish this goal. By having blood pressure under control, you help reduce the risks of stroke, heart attacks, along with other cardiovascular diseases and kidney failure.