Enalapril vs Losartan

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For patients with hypertension or heart failure, certain drugs that alter the concentrations of chemicals in the body that are linked to regulating blood pressure and fluid balance can help in managing symptoms. Enalapril and Losartan are two such drugs that are prescribed for these conditions. They each impact different mechanisms within the cardiovascular system but both have effects on lowering blood pressure and mitigating strain on the heart. Enalapril is an angiotensin-converting enzyme (ACE) inhibitor, which works by blocking a chemical called angiotensin II from constricting blood vessels — thus allowing for smoother flow of blood. On the other hand, Losartan belongs to a class of medications known as angiotensin II receptor blockers (ARBs). It operates primarily by inhibiting or blocking the effect of angiotensin II at its receptor level which results in dilation of blood vessels thereby reducing overall systemic resistance and afterload on the heart.

What is Enalapril?

Enalapril, commonly known as Vasotec among other brand names, was one of the first drugs in the ACE inhibitor class of antihypertensives. It was approved by the FDA in 1985 and is a prodrug that needs to be metabolized into its active form, enalaprilat. Enalapril works by blocking an enzyme called angiotensin-converting enzyme (ACE), which plays a vital role in regulating blood pressure and fluid balance. By inhibiting ACE’s function, Enalapril helps relax and widen your blood vessels leading to lower blood pressure.

Losartan, on the other hand, is part of another group of medications called angiotensin receptor blockers (ARBs). Approved by the FDA in 1995 under the brand name Cozaar, Losartan also targets the renin-angiotensin system but does so differently from Enalapril. Instead of preventing production like its counterpart, it blocks receptors where angiotensin II would typically bind thus stopping this hormone's effects.

Both drugs are used for treating high blood pressure and heart failure but they work in slightly different ways which can lead to different side effects - although these tend to be mild with both medications.

What conditions is Enalapril approved to treat?

Enalapril is approved for the management of various cardiovascular conditions, such as:

  • Hypertension, both as a standalone treatment and in combination with other antihypertensive agents
  • Symptomatic heart failure to decrease mortality and hospitalization rates
  • Asymptomatic left ventricular dysfunction (reduced ejection fraction) to delay the development of overt heart failure and decrease the incidence of hospitalization for heart failure.

How does Enalapril help with these illnesses?

Enalapril works to manage hypertension by inhibiting the action of an enzyme known as angiotensin-converting enzyme (ACE). This reduces the production of angiotensin II, a hormone that causes constriction of blood vessels and release of another hormone called aldosterone which increases sodium reabsorption in kidneys. The overall effect is relaxation and widening of blood vessels along with reduced fluid volume, leading to lower blood pressure. Angiotensin II also has direct effects on the heart apart from regulating blood pressure, it promotes cardiac remodeling which could lead to pathological changes in people with heart disease. By blocking its formation, Enalapril can help patients manage their condition and stabilize their cardiovascular health.

What is Losartan?

Losartan, marketed under the brand name Cozaar among others, is a medication mainly used to treat high blood pressure. It's an angiotensin II receptor antagonist (ARB) that works by blocking the action of certain natural substances that tighten the blood vessels, making the heart pump more efficiently and reducing strain on it. Losartan was first approved by the FDA in 1995.

As losartan is not an ACE inhibitor like enalapril, it doesn't prevent conversion of angiotensin I to angiotensin II but blocks its effects instead. This difference in mechanism leads to different side-effect profiles between these two medications: unlike ACE inhibitors such as enalapril, ARBs like losartan are less likely to cause coughing or affect potassium levels. Losartan may be a better choice for people who have experienced side effects from other drugs meant to control high blood pressure or for those with kidney disease related to type 2 diabetes.

What conditions is Losartan approved to treat?

Losartan is approved for the treatment of a variety of cardiovascular conditions, including:

  • Hypertension (high blood pressure)
  • Diabetic nephropathy (kidney damage due to diabetes)
  • Reducing stroke risk in patients with hypertension and left ventricular hypertrophy (enlargement or thickening of the wall of the heart's main pumping chamber).

How does Losartan help with these illnesses?

Losartan is an angiotensin II receptor antagonist that plays a crucial role in managing blood pressure and reducing the risk of stroke in certain individuals. It works by blocking the binding of angiotensin II to its receptors, thereby inhibiting vasoconstriction (narrowing of blood vessels) and the release of aldosterone, a hormone responsible for regulating salt and water balance in the body. This action results in lowered blood pressure and reduced strain on your heart. Losartan's mechanism differs from enalapril, which belongs to a class called ACE inhibitors that prevent the formation of angiotensin II rather than blocking its effects at the receptor level. While both drugs serve similar therapeutic goals, losartan may be chosen over enalapril when patients experience certain side effects like persistent cough associated with ACE inhibitors or have difficulty tolerating them due to other health reasons.

How effective are both Enalapril and Losartan?

Both enalapril and losartan have well-established histories of success in treating patients with hypertension, and they were initially approved by the FDA only a few years apart. Since they act on different aspects of the renin-angiotensin system, they may be prescribed under different circumstances. The effectiveness of enalapril and losartan was directly studied in a double-blind clinical trial in 1997; both medications demonstrated similar efficacy in managing symptoms of hypertension as well as similar safety profiles. In this study, none of the metrics used to measure efficacy for controlling blood pressure differed significantly between patients receiving enalapril or those receiving losartan.

One review from 2009 reported that enalapril is effective at reducing blood pressure within an hour after ingestion, which makes it suitable for acute management of high blood pressure episodes. Its side effect profile is generally favorable compared to many other antihypertensive drugs. Furthermore, it has been widely prescribed around the world due its long history and established effectiveness against hypertension.

A meta-analysis conducted in 2016 indicated that losartan seems more effective than placebo when treating mild to moderate essential hypertension, but its efficiency appears comparable to other common antihypertensive drugs such as ACE inhibitors like Enalapril or beta blockers. Nonetheless, Losartan's unique mechanism action (as an angiotensin receptor blocker) can make it a preferred choice among hypertensive patients who did not respond well to ACE inhibitors due its lower incidence rates for coughing - one common side effect associated with ACE inhibitor use.

abstract image of a researcher studying a bottle of drug.

At what dose is Enalapril typically prescribed?

Oral dosages of Enalapril typically range from 5-40 mg/day, but research shows that an initial dose of 5 mg/day is usually sufficient for treating hypertension in many adults. The same goes for Losartan where the usual starting dose is also around 50 mg/day but can be reduced to as low as 25mg or increased up to a maximum daily dosage of 100mg depending on patient response. For children and adolescents, the dosage should always be determined by a healthcare provider based on body weight and blood pressure goals. In both these cases, the medication dosage may need adjustment after several weeks if there's no adequate response. It's crucial not to exceed the maximum recommended daily doses: 40mg for Enalapril and 100mg for Losartan.

At what dose is Losartan typically prescribed?

Losartan treatment often starts at a dosage of 50 mg/day taken once daily. Depending on how your body responds to this medication, the dose can be increased over several weeks to a maximum of 100 mg/day. This max dosage can be divided into two doses of 50 mg each and spaced out with an interval of about 12 hours if required. If there is no improvement in blood pressure levels after adjusting the dosage upwards, it may necessitate further medical investigation and potential adjustment in medication strategy.

What are the most common side effects for Enalapril?

Common side effects of Enalapril may include:

  • Dizziness or lightheadedness as your body adjusts to the medication
  • Dry cough
  • Fatigue and weakness (Asthenia)
  • Nausea, diarrhea
  • Decreased sexual ability

On the other hand, Losartan may cause:

  • Dizziness due to a drop in blood pressure
  • Upper respiratory infections such as flu-like symptoms or sinusitis
  • Stomach pain and nausea
  • Tiredness (fatigue)
  • Persistent dry cough

Keep in mind that these are not all the possible side effects. If you experience any unusual symptoms, reach out to your healthcare provider immediately.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Enalapril?

Enalapril and Losartan are both used to control high blood pressure, but they can cause different side effects. While enalapril is generally well tolerated, it has been associated with some adverse reactions including:

  • Allergic responses such as swelling of the face, lips, tongue or throat
  • Difficulty breathing or swallowing
  • Signs of liver problems: upper stomach pain, dark urine, jaundice (yellowing of the skin or eyes)
  • Symptoms indicating low white blood cell counts - sudden weakness or ill feeling, fever, chills
  • High potassium levels in the body - slow heart rate, weak pulse muscle weakness

Similarly for Losartan look out for:

  • Changes in urinary frequency and volume which may indicate kidney issues.
  • Feeling light-headed due to a drop in blood pressure.
  • High potassium level symptoms include nausea and slow or unusual heart rate.

Regardless of which medication you're taking if any severe side effects occur seek immediate medical attention.

What are the most common side effects for Losartan?

Losartan could cause certain side effects in some individuals, including:

  • Dry cough or sore throat
  • Nasal congestion
  • Dizziness and lightheadedness, particularly when getting up from a sitting or lying position
  • Stomach discomfort, nausea or diarrhea
  • Sleep disturbances
  • Fatigue and muscle weakness
  • Changes in the heart rate such as slow heartbeat
  • Skin rash or itching
  • Weight fluctuations may occur but are less common. Increased urination can be particularly notable. It is crucial to monitor for signs of dehydration if this occurs. Some people might experience headaches. However, severe pain should be reported immediately to your healthcare provider. Muscle cramps and joint pain can also happen occasionally.

Remember that these are potential side effects; not everyone who takes Losartan will experience them. If you do encounter any unusual symptoms while on this medication, it's essential to discuss them with your doctor promptly.

Are there any potential serious side effects for Losartan?

Losartan, while generally well-tolerated and effective for treating high blood pressure, can occasionally cause severe adverse reactions. These may include:

  • Allergic reactions such as hives, difficulty breathing or swallowing, swelling of your face or throat
  • Skin pain followed by a red or purple skin rash that spreads (especially in the face or upper body) causing blistering and peeling
  • Changes in urination patterns: Passing little to no urine; painful or difficult urination; rapid weight gain from fluid retention
  • Symptoms related to an imbalance of electrolytes in the body like weakness, irregular heartbeats, muscle cramps/weakness
  • Severe ongoing stomach pain with nausea and vomiting

If you notice any of these signs after starting Losartan treatment, seek immediate medical attention.

Contraindications for Enalapril and Losartan?

Like other medications, both Enalapril and Losartan may cause adverse reactions in some individuals. If you notice any serious side effects such as a high potassium blood level (symptoms include muscle weakness, slow heart rate), kidney problems (symptoms include change in the amount of urine) or symptoms of angioedema (like swelling hands/legs, trouble breathing, signs of infection like fever or persistent sore throat), please seek immediate medical attention.

Neither Enalapril nor Losartan should be taken if you're also using aliskiren and have diabetes or kidney disease. Always inform your physician about all the medications you are currently taking; certain drugs require a period to clear from your system before starting with either Enalapril or Losartan to prevent dangerous interactions. For example, if you've been on an Angiotensin Receptor Blocker (ARB) or Aliskiren do not start with enalapril immediately.

How much do Enalapril and Losartan cost?

For the brand name versions of these drugs:

  • The price of 30 tablets of Vasotec, which contains Enalapril (20 mg), averages around $100, working out to approximately $3.33/day.
  • The price of 30 tablets of Cozaar, which contains Losartan (50 mg), averages about $120, or roughly $4/day.

Thus, if you are in the higher dosage range for Vasotec (i.e., 40 mg/day or higher), then brand-name Cozaar may be less expensive on a per-day treatment basis. However, cost should not be a primary consideration in determining which drug is right for you - both drugs have different side effect profiles and individual effectiveness can vary.

For the generic versions of Enalapril and Losartan:

  • Generic enalapril is available in packs from 15 up to 500 tablets (5mg to 20mg strengths) with costs starting from as low as about $0.10 per day depending on pack size and strength.
  • Generic losartan starts at similar prices but can reach up to about $1 per day depending on your dose and where you buy it.

Again though remember that while cost considerations are important they're not everything: always make sure any medication suits your specific needs first.

Popularity of Enalapril and Losartan

Enalapril, in both generic form and under brand names such as Vasotec, was estimated to have been prescribed to about 7 million people in the US in 2020. Enalapril accounted for approximately 14% of ACE inhibitor prescriptions in the US. This drug has been used since the early '80s and it is part of the WHO’s List of Essential Medicines.

Losartan, including its brand version Cozaar, was prescribed to around 37 million people in USA during last year. In the US, Losartan accounts for almost half (48%) of all angiotensin II receptor blocker (ARB) prescriptions and remains a popular choice due to its efficacy and tolerability profile. The prevalence of losartan has increased over time with an overall positive trend since its approval by FDA back in 1995.


Both Enalapril and Losartan have extensive usage records in patients with hypertension, supported by numerous clinical studies indicating that they are more effective than placebo treatments. Sometimes these drugs can be used together, but this would require careful consideration by a physician due to contraindications. They function differently: Enalapril is an ACE inhibitor while Losartan is an angiotensin receptor blocker (ARB). As such, they tend to be prescribed under different circumstances.

Enalapril is often considered as a first-line treatment option for hypertension and heart failure whereas Losartan may usually be seen as an alternative for those who cannot tolerate ACE inhibitors or need additional blood pressure control.

Both medications are available in generic form which represents significant cost savings especially for patients paying out of pocket. Both Enalapril and Losartan might require time before their full effects become noticeable.

There's similarity between the side effect profiles of both drugs; however, cough is less common with Losartan compared to Enalapril. For both medications, it's crucial that patients monitor their blood pressure regularly when starting treatment and seek medical attention immediately if symptoms persist or worsen.