Sartans (Angiotensin II Receptor Blockers): Advice for New Patients

Sartans, also known as angiotensin II receptor blockers (ARBs), are a newer class of medications used to treat high blood pressure (hypertension).  These drugs work by blocking the effects of a hormone called angiotensin II, which causes blood vessels to constrict and raise blood pressure.

By preventing this constriction, sartans allow blood vessels to relax and widen, effectively lowering blood pressure levels. This guide provides information about sartans, a class of medication recently prescribed to you by your doctor. We discuss how sartans work, their benefits, safety considerations, and what to expect when starting treatment.  The goal is to help you manage your hypertension effectively and safely using these blood pressure-lowering drugs.

What are Sartans/Angiotensin II Receptor Blockers?

How Sartans Work

Sartans, or angiotensin II receptor blockers (ARBs), exert their blood pressure-lowering effects through a specific mechanism of action. They work by blocking the angiotensin II hormone from binding to its receptors, known as AT1 receptors, which are found in the muscles surrounding blood vessels. Angiotensin II is a potent vasoconstrictor, meaning it causes the narrowing or constriction of blood vessels. When angiotensin II binds to AT1 receptors, it triggers a series of events that lead to the tightening of these blood vessel muscles, ultimately increasing blood pressure. By selectively blocking the AT1 receptors, sartans prevent angiotensin II from exerting its vasoconstrictor effects.  This action allows the blood vessels to relax and dilate, or widen, thereby reducing the resistance to blood flow and lowering overall blood pressure levels.

Types / Examples of Sartans

There are several different sartan medications available on the market, each with a unique chemical structure but sharing the same mechanism of action.  Some of the most commonly prescribed sartans include:

While these sartan medications share a similar mechanism of action, they may differ in their pharmacokinetic properties, such as bioavailability, half-life, and metabolism.  Your doctor will consider these factors, as well as your individual health profile and potential drug interactions, when selecting the most appropriate sartan for your treatment. It’s important to note that sartans are typically prescribed once daily, as their long-lasting effects allow for convenient once-a-day dosing. However, always follow your doctor’s instructions regarding the specific dosage and timing for your prescribed sartan medication.

Benefits of Sartans

Effective Blood Pressure Control by Sartans

One of the primary benefits of sartans is their proven efficacy in lowering high blood pressure (hypertension). Numerous clinical studies have demonstrated the ability of these medications to significantly reduce both systolic (top number) and diastolic (bottom number) blood pressure readings. In fact, sartans have been shown to be just as effective as other widely-used antihypertensive drug classes, such as angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers, and diuretics, in achieving blood pressure control. For example, a meta-analysis published in the Journal of Hypertension compared the blood pressure-lowering effects of various sartan medications (losartan, valsartan, irbesartan, and candesartan) with those of ACE inhibitors.  The study found that sartans were equally effective in reducing both systolic and diastolic blood pressure levels, with no significant differences between the two drug classes.

Improved Tolerability of Sartans

Another advantage of sartans is their improved tolerability compared to ACE inhibitors, which are another commonly prescribed class of antihypertensive medications.  One of the most common side effects associated with ACE inhibitors is a persistent, dry cough, which can be bothersome and even lead to discontinuation of treatment in some patients. Sartans, on the other hand, do not cause this persistent dry cough, as they do not affect the breakdown of bradykinin, a substance involved in the cough reflex. This makes sartans a more tolerable option for patients who experience this side effect with ACE inhibitors. Additionally, sartans have a lower risk of causing angioedema, a potentially life-threatening swelling of the face, lips, tongue, or throat. Angioedema is a rare but serious side effect that can occur with ACE inhibitors, but it is much less common with sartans.

Once-Daily Dosing of Sartans

Most sartan medications are designed for once-daily dosing, which offers several advantages in terms of convenience and adherence to treatment.  Unlike some other antihypertensive drugs that require multiple daily doses, sartans can effectively control blood pressure with a single daily dose. This once-daily dosing regimen can improve patient adherence, as it is generally easier for individuals to remember and consistently take their medication when it is only required once per day.  Adherence to prescribed medication is crucial for achieving optimal blood pressure control and reducing the risk of complications associated with hypertension. Furthermore, the convenience of once-daily dosing can enhance patient satisfaction and quality of life, as it minimizes the disruption to daily routines and reduces the burden of remembering to take multiple doses throughout the day.

Potential Additional Benefits of Sartans

While sartans are primarily prescribed for the treatment of hypertension, emerging research suggests that they may offer additional benefits beyond blood pressure control.  These potential benefits include:

1. Kidney Protection in Diabetic Patients: Several studies have indicated that certain sartans, such as losartan and irbesartan, may help slow the progression of diabetic nephropathy (kidney disease) in patients with type 2 diabetes and hypertension. This protective effect on kidney function is particularly important, as diabetic nephropathy is a leading cause of end-stage renal disease.
2. Heart Failure Management: Some evidence suggests that sartans may be beneficial in the treatment of heart failure, particularly in patients who are intolerant to ACE inhibitors. For example, the CHARM (Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity) trial found that candesartan reduced the risk of cardiovascular death or hospital admission for heart failure in patients with chronic heart failure.
3. Gout Management: Certain sartans, such as losartan and irbesartan, have been shown to have a mild uric acid-lowering effect, which may be beneficial for patients with gout or hyperuricemia (high levels of uric acid in the blood).
4. Improved Sexual Function: Interestingly, several studies have reported improvements in sexual function, particularly in men, after treatment with sartans. This effect has been observed with various sartan medications, including losartan, valsartan, and telmisartan. While the exact mechanisms are not fully understood, it is believed that the improved blood flow and reduced oxidative stress associated with sartans may contribute to these benefits.

It is important to note that while these potential additional benefits are promising, more research is needed to fully understand the extent and clinical implications of these effects. Your doctor can provide more specific guidance on whether any of these potential benefits may be relevant to your individual health situation.

Common ACE Inhibitors

Safety Considerations When Taking Sartans

General Safety Profile of Sartans

Sartans are generally considered to be well-tolerated and safe medications, especially for elderly patients. However, it is important to remember that all medications carry some risks and potential side effects. Numerous clinical studies have demonstrated the favorable safety profile of sartans, particularly in comparison to other antihypertensive drug classes.  In fact, sartans are often recommended as a preferred option for elderly patients with hypertension due to their lower risk of certain side effects, such as persistent dry cough and angioedema, which can be more problematic in this age group. That being said, like any medication, sartans can still cause side effects in some individuals. Common side effects may include dizziness, headache, fatigue, and muscle cramps. However, these side effects are typically mild and often subside as the body adjusts to the medication.

Drug Interactions with Sartans

When taking sartans, it is important to be aware of potential drug interactions with other medications.  One key consideration is the concomitant use of sartans with other antihypertensive drugs, as this can lead to an excessive drop in blood pressure, potentially causing dizziness, lightheadedness, or even fainting. Additionally, sartans should be used with caution in combination with nonsteroidal anti-inflammatory drugs (NSAIDs) or selective cyclooxygenase-2 (COX-2) inhibitors, as these medications can impair kidney function and reduce the blood pressure-lowering effects of sartans. Specific drug interactions have also been identified with certain sartan medications. For example, telmisartan should not be taken with digoxin, as it can increase the blood levels of this cardiac glycoside, potentially leading to digoxin toxicity.

What to Monitor When Taking Sartans

While sartans are generally well-tolerated, it is important to monitor kidney function, especially in patients with pre-existing kidney disease or those taking medications that can potentially affect kidney function, such as NSAIDs or diuretics. Your doctor may recommend periodic blood tests to assess your kidney function while taking a sartan. Additionally, it is crucial to report any side effects or concerns to your healthcare provider promptly, as they may need to adjust your dosage or consider an alternative medication. By being aware of the potential safety considerations and following your doctor’s instructions carefully, you can minimize the risks associated with sartan therapy and ensure that you receive the maximum benefits from these effective blood pressure-lowering medications.

Comparing Sartan Medications

While all sartan medications share the same mechanism of action by blocking the angiotensin II receptor, they differ in their pharmacokinetic properties and may have varying degrees of suitability for certain patient populations.

Similarities and Differences Among Sartans

Mechanism of Action

All sartans selectively block the angiotensin II type 1 (AT1) receptor, preventing the vasoconstrictor effects of angiotensin II and thereby lowering blood pressure. This shared mechanism of action is what defines the sartan class of antihypertensive medications.

Pharmacokinetic Differences

Despite their similar mechanism of action, sartan medications can vary significantly in their pharmacokinetic profiles, including:

• Half-life: The half-life of a drug refers to the time it takes for half of the administered dose to be eliminated from the body. Sartans with longer half-lives, such as telmisartan (24 hours) and azilsartan (11 hours), may provide more consistent blood pressure control with once-daily dosing compared to those with shorter half-lives, like eprosartan (5-9 hours).
• Bioavailability: Bioavailability refers to the fraction of the administered dose that reaches the systemic circulation and is available for therapeutic action. Sartans with higher bioavailability, such as telmisartan (42-58%) and valsartan (25%), may require lower doses to achieve the desired therapeutic effect compared to those with lower bioavailability, like eprosartan (13%).
• Metabolism and Elimination: Sartans are metabolized and eliminated from the body through various pathways, including hepatic (liver) metabolism and renal (kidney) excretion. Differences in these pathways can affect the potential for drug interactions and the need for dose adjustments in patients with liver or kidney impairment.

The following table summarizes some key pharmacokinetic differences among commonly prescribed sartan medications:

Potential Preference for Certain Patients

While all sartans are generally considered safe and effective for the treatment of hypertension, certain medications within this class may be preferred for specific patient populations based on clinical evidence and individual patient factors.

Elderly Patients Taking Sartans

Sartans are often recommended as a preferred antihypertensive option for elderly patients due to their favorable safety profile and lower risk of certain side effects, such as persistent dry cough and angioedema, compared to ACE inhibitors. Among the sartan medications, candesartan has been extensively studied in elderly patients and has demonstrated excellent efficacy and tolerability in this population. Several clinical trials have shown that candesartan effectively lowers blood pressure, particularly during the nighttime hours, which is beneficial for reducing the risk of cardiovascular events in elderly patients.

Diabetic Kidney Disease

Patients with type 2 diabetes mellitus and hypertension are at an increased risk of developing diabetic nephropathy (kidney disease). Certain sartans, such as irbesartan and losartan, have been shown to provide renoprotective effects and may help slow the progression of diabetic nephropathy in these patients. The IDNT (Irbesartan Diabetic Nephropathy Trial) and RENAAL (Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan) studies demonstrated that irbesartan and losartan, respectively, were effective in reducing the risk of end-stage renal disease and slowing the decline in kidney function in patients with type 2 diabetes and nephropathy.

When Starting a Sartan: What to Expect

How Sartans Are Prescribed

When starting a sartan medication for the treatment of hypertension, your doctor will typically begin with a low dose and gradually increase it over time until your blood pressure is adequately controlled.  This approach, known as dose titration, allows your body to adjust to the medication and minimizes the risk of potential side effects. It’s important to note that the full blood pressure-lowering effect of a sartan may not be apparent immediately.  It can take several weeks for the medication to reach its maximum therapeutic effect. During this time, your doctor may monitor your blood pressure closely and adjust the dosage as needed.

Common Side Effects of Sartans

While sartans are generally well-tolerated, some patients may experience mild side effects, particularly when starting the medication or after a dose increase.  Common side effects can include:

• Dizziness: Sartans can cause a temporary drop in blood pressure, leading to dizziness or lightheadedness, especially when standing up from a seated or lying position.
• Headache: Some patients may experience headaches, particularly in the initial stages of treatment.
• Fatigue: Feeling tired or fatigued is another potential side effect of sartan therapy.

To minimize these side effects, it’s essential to stay well-hydrated and avoid sudden changes in posture. If you experience persistent or severe side effects, be sure to inform your healthcare provider, as they may need to adjust your dosage or consider an alternative medication.

Lifestyle Considerations

While sartans are effective in lowering blood pressure, it’s crucial to remember that they are just one component of a comprehensive treatment plan for hypertension.  Lifestyle modifications, such as following a healthy diet, engaging in regular physical activity, and achieving a healthy body weight, play a vital role in managing high blood pressure and reducing the risk of associated complications. Your healthcare provider may recommend specific dietary changes, such as reducing your sodium intake, increasing your consumption of fruits and vegetables, and limiting alcohol consumption.  Regular exercise, even moderate activities like brisk walking, can also contribute to better blood pressure control and overall cardiovascular health. If you are overweight or obese, your doctor may advise you to adopt a weight loss program, as losing excess weight can significantly improve blood pressure levels and reduce the risk of complications associated with hypertension. It’s important to understand that sartans are not a substitute for a healthy lifestyle but rather a complementary treatment option. By combining sartan therapy with appropriate lifestyle modifications, you can maximize the benefits of these medications and achieve better long-term control of your blood pressure.

Adherence and Follow-Up

Importance of Taking Sartans as Prescribed

Adhering to your prescribed sartan medication regimen is crucial for achieving and maintaining effective blood pressure control. It’s essential to take your sartan consistently, at the same time each day, and as directed by your healthcare provider. Skipping doses or stopping your sartan abruptly without consulting your doctor can lead to a rebound increase in blood pressure, potentially putting you at risk for complications such as heart attack, stroke, or kidney damage. If you experience any side effects or have concerns about your medication, it’s important to discuss them with your doctor rather than stopping the sartan on your own. Your healthcare provider may be able to adjust the dosage, switch to a different sartan, or provide guidance on managing side effects.

Follow-Up Monitoring with Your Doctor

When you start taking a sartan for hypertension, your doctor will likely schedule regular follow-up appointments to monitor your blood pressure and assess the effectiveness of the medication.  These visits may involve:

1. Blood Pressure Checks: Your healthcare provider will measure your blood pressure at each visit to ensure that the sartan is effectively lowering your levels to the target range.
2. Kidney Function Tests: Sartans can potentially affect kidney function, especially in patients with pre-existing kidney disease or those taking other medications that may impact renal function. Your doctor may order periodic blood tests, such as serum creatinine and estimated glomerular filtration rate (eGFR), to monitor your kidney function.
3. Urine Tests: In some cases, your doctor may request a urine sample to check for the presence of protein, which can be an indicator of kidney damage.
4. Electrolyte Monitoring: Sartans can sometimes affect electrolyte levels, such as potassium and sodium. Your healthcare provider may order blood tests to monitor your electrolyte levels, especially if you are also taking diuretics or have kidney disease.

It’s essential to attend all scheduled follow-up appointments and comply with any recommended monitoring tests. This allows your doctor to make necessary adjustments to your treatment plan and ensure that you are receiving the maximum benefits from your sartan medication while minimizing potential risks.

Taking Control of Your Blood Pressure with Sartans

Sartans, also known as angiotensin II receptor blockers (ARBs), are a class of medications used to treat hypertension (high blood pressure) by blocking the effects of the angiotensin II hormone, which causes blood vessels to constrict and raise blood pressure. These medications offer several benefits, including:

• Effective blood pressure control comparable to other antihypertensive drug classes
• Improved tolerability, with a lower risk of persistent dry cough and angioedema compared to ACE inhibitors
• Convenient once-daily dosing for improved adherence
• Potential additional benefits, such as kidney protection in diabetic patients and improved sexual function

While sartans are generally well-tolerated, it’s important to be aware of potential side effects, drug interactions, and the need for monitoring kidney function. Following your healthcare provider’s instructions regarding dosing, lifestyle modifications, and regular follow-up appointments is crucial for maximizing the benefits and safety of sartan therapy. Remember, managing hypertension requires an active partnership between you and your healthcare team.  Don’t hesitate to ask questions, report any concerns, and actively participate in your care to achieve optimal blood pressure control and reduce the risk of complications associated with high blood pressure.

About the Author

Tetiana Melnyk is a healthcare journalist at Mister Blister specializing in legal and regulatory analysis of Ukraine's healthcare sector. A medical graduate of Vinnitsa National University, Tetiana leverages her background as a practicing physician to provide insightful, critically-examined coverage. Her expertise stems from hands-on clinical work across Kyiv and medical research experience.