Major Research Findings

Enalapril, an angiotensin-converting enzyme inhibitor, has been shown to effectively lower blood pressure in patients with severe hypertension. 8 In a study comparing enalapril to losartan, both medications effectively reduced blood pressure, with enalapril showing slightly greater reduction, although the difference was small. 8 Both medications were well-tolerated, with headache being the most common side effect. 8

Enalapril has also demonstrated efficacy in treating mild to moderate essential hypertension. 6 In a large-scale, multi-clinic study, enalapril was found to significantly reduce both systolic and diastolic blood pressure compared to propranolol. 6 Enalapril also required fewer patients to need additional hydrochlorothiazide for optimal blood pressure control. 6 The study concluded that enalapril is a safe and well-tolerated option for long-term treatment of hypertension.

In Asian patients with hypertension, enalapril has been studied as both monotherapy and in combination with hydrochlorothiazide. 1 The combination therapy showed greater efficacy and allowed for lower doses of enalapril compared to monotherapy. 1

Studies have explored the psychotropic effects of enalapril in healthy volunteers. 5 While enalapril lowered blood pressure and increased heart rate, it did not affect mood but could enhance attention and alertness. 5

In patients already receiving diuretics, enalapril has been shown to be as effective as atenolol in reducing blood pressure. 3 However, the study highlighted the importance of starting with a low dose of enalapril in patients already on diuretics, as even 5 mg could be hazardous in some individuals. 3

Research has investigated the interaction between sodium intake, enalapril, and blood pressure control. 4 Increasing sodium intake raised blood pressure regardless of enalapril use, but enalapril was still effective in lowering blood pressure even in patients with high sodium intake. 4 Combining enalapril with a low sodium diet resulted in an additive effect on blood pressure reduction. 4

Enalapril has also been compared to prazosin in hypertensive patients with diabetes. 10 Both drugs demonstrated comparable antihypertensive efficacy, but prazosin showed more favorable effects on certain serum lipid fractions. 10 Enalapril was associated with a higher incidence of side effects compared to prazosin. 10

Clinical experience with enalapril in Bulgaria indicates its high efficacy and good tolerability in treating hypertension. 9 The most common side effects reported were headache, dizziness, orthostatic effects, and abdominal pain, while more serious side effects like dry cough were less frequent. 9

Enalapril has been shown to have a potent antihypertensive effect compared to atenolol. 2 In patients with mild to moderate hypertension, enalapril produced a greater reduction in systolic blood pressure than atenolol. 2

Studies have investigated the effects of enalapril on angiotensin-converting enzyme (ACE) during both acute and chronic therapy. 7 Enalapril was shown to inhibit ACE activity and reduce blood pressure. 7 However, chronic enalapril treatment may induce ACE, leading to a shift in the drug level:ACE inhibition curve. 7

Benefits and Risks

Benefit Summary

Enalapril has consistently demonstrated its effectiveness in lowering blood pressure in patients with various types of hypertension. 6 2 8 It has also been found to be a safe and well-tolerated option for long-term use. 6 Enalapril has a favorable side effect profile compared to other antihypertensive medications. 5 Additionally, enalapril can be used in combination with other medications to further improve blood pressure control. 1 3

Risk Summary

The most common side effects associated with enalapril include headache, dizziness, orthostatic hypotension, and abdominal pain. 9 Less common, but more serious side effects may include a dry persistent cough. 9 It is important to start with a low dose of enalapril, especially in patients already taking diuretics, as higher doses may be hazardous. 3 Enalapril is not recommended for use during pregnancy. 9

Comparison Across Studies

Commonalities

The studies consistently show that enalapril is an effective antihypertensive agent. 6 2 8 It is generally well-tolerated, with a favorable side effect profile compared to other antihypertensive medications. 5 Enalapril is effective in treating different types of hypertension, including severe hypertension, mild to moderate essential hypertension, and hypertension in Asian populations. 8 6 1 These studies suggest that enalapril is a safe and effective option for managing hypertension in a variety of patients.

Differences

The studies vary in terms of the specific populations studied, the dosage of enalapril used, and the methods of analysis. 8 6 1 For example, some studies focused on patients with severe hypertension while others explored mild to moderate cases. 8 6 The dosage of enalapril used in the studies also varied depending on the severity of the hypertension and individual patient characteristics. 1 3 These differences highlight the need for further research to optimize the use of enalapril for individual patients.

Consistency and Discrepancies in Results

The overall results of these studies consistently demonstrate that enalapril is an effective antihypertensive agent. 6 2 8 However, there are some discrepancies regarding optimal dosing and the potential for side effects. 3 These differences suggest that further research is necessary to determine the optimal dosage and application of enalapril in different patient populations. 3

Implications for Real-World Applications

Enalapril is a valuable treatment option for managing hypertension. However, it is essential to consider potential risks and side effects, particularly in patients with other health conditions or who are already taking other medications. 3 Starting with a low dose and closely monitoring blood pressure and potential side effects is crucial. 3 It is also important to discuss potential risks with healthcare professionals, especially for pregnant women or those with specific allergies or health concerns. 9

Limitations of Current Research

While the studies reviewed provide valuable insights into the efficacy and safety of enalapril, it is important to acknowledge their limitations. 1 3 Most studies have a relatively small sample size, which may limit the generalizability of their findings. 3 Additionally, most studies focused on short-term treatment, and the long-term effects of enalapril require further investigation. 7

Future Research Directions

Further research is needed to optimize the use of enalapril for different patient populations. 1 3 This includes investigating optimal dosages and treatment regimens for various degrees of hypertension. 8 6 1 Long-term studies are also essential to assess the long-term efficacy and safety of enalapril in managing hypertension. 7 More research is also needed to understand the potential impact of enalapril on specific patient groups, such as pregnant women and those with underlying health conditions. 9 3

Conclusion

Enalapril is an effective and generally well-tolerated antihypertensive medication. 6 2 8 It has been shown to be effective in treating different types of hypertension, including severe hypertension, mild to moderate essential hypertension, and hypertension in Asian populations. 8 6 1 However, it is essential to be aware of potential side effects and to start with a low dose, especially in patients already taking diuretics. 3 Enalapril is not recommended for use during pregnancy. 9 3 It is recommended to discuss the use of enalapril with a healthcare professional to ensure it is the most appropriate treatment option for individual needs. 9