Lisinopril and telmisartan are two medications frequently prescribed to manage high blood pressure, a condition that can lead to serious health problems if left uncontrolled. While both drugs aim to reduce blood pressure effectively, they achieve this through different physiological pathways within the body. Understanding these distinctions can help clarify why a healthcare provider might choose one over the other for an individual patient.
How They Work
Lisinopril functions as an Angiotensin-Converting Enzyme (ACE) inhibitor, a class of medications that target an enzyme. This enzyme, ACE, converts angiotensin I into angiotensin II, a potent chemical that narrows blood vessels. By blocking the action of ACE, lisinopril prevents the formation of angiotensin II, leading to the relaxation and widening of blood vessels. This vasodilation reduces the pressure within the arteries, lowering overall blood pressure.
Telmisartan belongs to a different class of drugs called Angiotensin Receptor Blockers (ARBs). Instead of preventing the formation of angiotensin II, telmisartan directly blocks angiotensin II from binding to its receptors, primarily the AT1 receptor, found on blood vessel walls. When angiotensin II cannot bind to these receptors, its vasoconstrictive effects are diminished, resulting in blood vessel relaxation and reduced blood pressure. Despite their distinct mechanisms of action, both lisinopril and telmisartan ultimately work to counter the effects of angiotensin II, decreasing blood pressure.
What They Treat
Both lisinopril and telmisartan are used for treating essential hypertension, high blood pressure without an identifiable cause. Managing hypertension with these medications reduces the risk of serious cardiovascular events like strokes and heart attacks. Beyond blood pressure management, each medication also has specific additional approved indications.
Lisinopril is often prescribed after a heart attack to improve survival rates. It also manages heart failure, improving the heart’s pumping efficiency and reducing fluid retention. Telmisartan reduces cardiovascular risk in high-risk patients, such as those with a history of coronary artery disease or stroke. It also treats diabetic nephropathy, a kidney disease that can develop in individuals with type 2 diabetes.
Side Effects and Important Considerations
Lisinopril can cause a characteristic dry, persistent cough in some individuals, which is thought to be due to bradykinin accumulation. A more serious but rare side effect associated with lisinopril is angioedema, rapid swelling of the face, lips, tongue, or throat, requiring immediate medical attention. Changes in kidney function and elevated potassium levels in the blood are also potential concerns with lisinopril use.
Telmisartan has a lower incidence of dry cough and angioedema compared to lisinopril, making it an alternative for patients who cannot tolerate the cough. Common side effects include dizziness and fatigue, especially when starting or increasing the dose. Both medications carry a risk of hyperkalemia (increased blood potassium levels), which can be dangerous, especially with kidney impairment. Both are strictly contraindicated during pregnancy due to fetal harm risk. Nonsteroidal anti-inflammatory drugs (NSAIDs) can reduce their blood pressure-lowering effect and increase kidney problem risk when taken concurrently.
Choosing Between Them
Choosing between lisinopril or telmisartan is highly individualized, depending on a patient’s medical profile. If a patient develops a bothersome dry cough from lisinopril or another ACE inhibitor, telmisartan or another ARB is often an alternative due to its lower propensity for this side effect. While both are effective at lowering blood pressure, subtle differences in their additional benefits influence the choice.
Lisinopril’s established role in treating heart failure and improving outcomes after a heart attack makes it a preferred choice in those scenarios. Telmisartan’s evidence for cardiovascular risk reduction in high-risk patients and its use in diabetic nephropathy highlight its distinct advantages. The ultimate decision involves a thorough evaluation of the patient’s medical history, co-existing health conditions, other medications, and tolerance to side effects, guided by a healthcare provider.