Lisinopril for Black Patients: Efficacy and Considerations

Lisinopril lowers blood pressure less effectively as a standalone treatment in Black patients compared with white patients, but that reduced response does not mean the drug is useless or should always be avoided. The gap narrows substantially when a low-dose diuretic is added, and in conditions like heart failure, the survival benefit of ACE inhibitors appears similar across racial groups. The full picture involves biology, side-effect profiles, guideline recommendations, and the practical realities of managing hypertension in a population that carries a disproportionate burden of cardiovascular disease.

How Much Less Effective Is Lisinopril Alone at Lowering Blood Pressure?

The clearest data come from the ALLHAT trial, one of the largest hypertension studies ever conducted. Among Black participants, those randomized to lisinopril had systolic blood pressure about 4 mm Hg higher than those given chlorthalidone (a thiazide diuretic) after five years of follow-up. Among non-Black participants, the difference between the two drugs was less than 1 mm Hg and not statistically meaningful.¹ A separate analysis of the same trial noted that the blood pressure gap between lisinopril and chlorthalidone was most pronounced in the first two years, when Black patients on chlorthalidone had roughly a 5/2 mm Hg advantage, and it shrank modestly to about 4/1 mm Hg by year four.²

Four millimeters of mercury may not sound like much, but at a population level it translates into real differences in cardiovascular events. In the ALLHAT Black subgroup, lisinopril was associated with a trend toward higher rates of heart disease events, including a hazard ratio of 1.19 for combined cardiovascular disease and 1.15 for combined coronary heart disease compared with chlorthalidone.¹ These findings are the main reason guidelines steer Black patients toward diuretics or calcium channel blockers as first-line monotherapy rather than ACE inhibitors like lisinopril.

Why the Difference Exists

Lisinopril works by blocking the angiotensin-converting enzyme, which is part of a hormonal cascade called the renin-angiotensin system. This system raises blood pressure by constricting blood vessels and telling the kidneys to hold onto sodium. In many Black individuals, particularly those with salt-sensitive hypertension, the renin-angiotensin system tends to run at a lower baseline level. When renin is already low, blocking ACE does not produce as large a drop in blood pressure because the system is not the primary driver of elevated pressure in the first place.³

Vascular biology adds another layer. Research has found that blood vessels from Black individuals tend to produce less bioavailable nitric oxide, a molecule that relaxes vessel walls. The issue is not underproduction of nitric oxide itself but increased breakdown of it by reactive oxygen species.⁴ A more recent study found that a receptor called endothelin A contributes to this reduced nitric oxide signaling in young non-Hispanic Black adults, and that blocking that receptor improved nitric oxide-dependent blood vessel relaxation.⁵ These vascular differences help explain why calcium channel blockers and diuretics, which act through different mechanisms, tend to be more effective at lowering blood pressure in this population. A systematic review suggested that low nitric oxide availability and high creatine kinase levels together may partly account for why hypertensive patients of African ancestry respond differently to various drug classes.⁶

It is worth stressing that these are population-level tendencies, not absolutes. Renin levels vary widely among individuals of any racial background, and some Black patients respond very well to lisinopril on its own. Race is a rough proxy for underlying physiology, not a deterministic one.

Angioedema and Cough Risks

Beyond reduced blood pressure lowering, Black patients face a meaningfully higher risk of two ACE inhibitor side effects that deserve separate attention: angioedema and persistent cough.

Angioedema is a sudden swelling of the lips, tongue, throat, or face that can become a medical emergency if it obstructs the airway. It is uncommon overall but substantially more frequent among Black patients taking ACE inhibitors. One study found that Black Americans had roughly four and a half times the risk of ACE inhibitor-related angioedema compared with white patients, even after adjusting for dose, specific drug, and concurrent medications.⁷ A UK case series found that 65 percent of reported ACE inhibitor angioedema cases involved Black or Afro-Caribbean patients.⁸

Researchers have identified some of the genetic factors behind this disparity. A variant in the XPNPEP2 gene was significantly more common in Black men who developed angioedema while on ACE inhibitors than in Black men who tolerated the drugs without problems.⁹ Another study identified a variant in the gene for neprilysin, an enzyme that breaks down bradykinin, as being associated with angioedema specifically in African Americans.¹⁰ In South African patients, a polymorphism in the bradykinin B2 receptor was linked to both angioedema and cough from ACE inhibitors, and patients who developed these reactions also had lower baseline ACE activity.¹¹ The common thread in these findings is that ACE inhibitors cause bradykinin to accumulate, and genetic differences in how quickly bradykinin gets cleared can determine who develops swelling or cough.

Persistent dry cough is the more common nuisance side effect. One study of patients on ACE inhibitors found that Black patients discontinued the medication because of cough at a rate of about 9.6 per 100 patients, compared with 2.4 per 100 among others. After adjusting for differences in baseline characteristics, Black patients still had roughly two and a half times the risk of stopping due to cough. Women were disproportionately affected, making up 70 percent of those who quit the drug for this reason.¹²

When Lisinopril Still Makes Sense

The blood pressure story is only part of the picture. ACE inhibitors, including lisinopril, have protective effects on the heart and kidneys that go beyond simply lowering pressure, and these benefits appear to extend to Black patients.

In heart failure with reduced ejection fraction, the data are encouraging. A meta-analysis examining the relationship between self-identified race and the survival benefit of angiotensin-inhibiting drugs found very similar results in Black and white patients: adjusted hazard ratios of 0.52 and 0.54, respectively, meaning both groups saw roughly a halving of their risk of death when treated.¹³ An earlier meta-analysis of major clinical trials confirmed beneficial reductions in all-cause mortality with ACE inhibitors in both Black and white patients with left ventricular dysfunction.¹⁴ A separate study of heart failure patients found that ACE inhibitor or ARB exposure was associated with a lower risk of death or re-hospitalization in both African American patients (hazard ratio 0.47) and white patients (hazard ratio 0.55), with no significant difference between the groups.¹⁵

For kidney protection, ACE inhibitors remain a standard recommendation in patients with diabetic kidney disease regardless of race. In a study of high-risk patients with diabetic nephropathy, the median urinary albumin-to-creatinine ratio (a marker of kidney damage) dropped by roughly 43 percent with treatment, and the reduction correlated with how much blood pressure improved.¹⁶ The kidney-protective effect of blocking the renin-angiotensin system is thought to come from reducing pressure inside the glomerulus, the kidney’s filtration unit, which is a separate mechanism from overall blood pressure control.

So while lisinopril may not be the ideal standalone blood pressure pill for many Black patients, it remains a valuable tool when heart failure, kidney disease, or diabetes is part of the clinical picture.

Combination Therapy Closes the Gap

The most practical takeaway from the evidence is that the blood pressure gap between lisinopril and other drugs largely disappears when you add a diuretic. In a study of predominantly Black, low-renin patients, lisinopril alone produced meaningful blood pressure reductions, and adding a low dose of hydrochlorothiazide (25 mg) brought most of the remaining non-responders to their blood pressure target.¹⁷ The mechanism is intuitive: a diuretic forces the kidneys to excrete sodium, which activates the renin-angiotensin system. Once that system is more active, blocking it with an ACE inhibitor becomes more effective.

A review of hypertension management in African Americans confirmed that the reduced responsiveness to ACE inhibitors as monotherapy is corrected when diuretics are added.¹⁸ The International Society on Hypertension in Blacks consensus statement recommends that when blood pressure is more than 15/10 mm Hg above goal, two-drug therapy should be used from the start, combining a calcium channel blocker or thiazide diuretic with a renin-angiotensin system blocker.

In practice, this means Black patients are not shut out from lisinopril. They are more likely to need it as part of a combination rather than as the only pill in the regimen. Many patients of any background end up on two or three medications anyway, since hypertension frequently requires combination therapy to reach target levels.

What the Guidelines Recommend

Multiple guideline bodies, including NICE in the UK, recommend that Black patients of any age begin with a calcium channel blocker or a thiazide-type diuretic rather than an ACE inhibitor as initial monotherapy.¹⁹ A pharmacotherapy review concluded that ACE inhibitors or ARBs should not routinely be started as the sole drug in Black patients with hypertension, given both the reduced blood pressure response and the limited outcomes data supporting that approach.²⁰

These guidelines are about first-line monotherapy, not about banning ACE inhibitors entirely. In patients who have a compelling reason to be on an ACE inhibitor, such as heart failure, chronic kidney disease, or a history of heart attack, the guidelines support their use regardless of race, typically as part of a multi-drug regimen.

ACE Inhibitors Versus ARBs in Black Patients

Angiotensin receptor blockers (ARBs) like losartan are sometimes considered an alternative to ACE inhibitors, partly because they are less likely to cause cough and angioedema. However, recent real-world data from England suggest the switch is not straightforward. Compared with ACE inhibitors, ARBs were associated with a higher rate of cardiovascular-related death in Black patients (hazard ratio 1.20). At the same time, switching to an ARB did reduce angioedema risk, with a number-needed-to-treat of about 204 to prevent one case.²¹ The finding that ARBs might not match ACE inhibitors on cardiovascular outcomes in Black patients complicates the assumption that they are a simple substitute. When the primary reason for switching is cough or a prior mild episode of angioedema, an ARB is reasonable. But when cardiovascular protection is the goal, the data warrant a more careful conversation between patient and clinician.

Adherence and Socioeconomic Realities

Any discussion of drug efficacy in Black patients is incomplete without acknowledging the structural factors that affect whether medications get taken consistently. Black patients have been found to have lower odds of adherence and persistence with blood pressure medications relative to white patients, with one study reporting adjusted odds of adherence of 0.46 for Black patients compared with white patients. Social determinants of health, including food insecurity, housing instability, and smoking, have a measurable impact on whether people stay on their medications. In a Medicaid cohort, patients in the groups with the most social risk factors were up to 36 percent less likely to be adherent to blood pressure therapy than those with fewer social risks.²²

These findings matter because the clinical trial data showing reduced efficacy of lisinopril in Black patients were generated under controlled conditions with monitored adherence. In the real world, where side effects like cough make patients more likely to stop taking their pills, and where cost, access, and trust in the healthcare system all play a role, the gap between what a drug can do and what it actually accomplishes can widen further. A drug that is slightly less potent and also less tolerable is a harder sell for long-term adherence. This practical reality reinforces the guideline preference for starting with drugs that are both more effective and better tolerated in this population, reserving ACE inhibitors for situations where their unique benefits are most needed.

The Genetics Behind Individual Variation

One of the more interesting frontiers in this area is pharmacogenomics, which tries to predict how an individual will respond to a drug based on their genetic profile rather than their racial category. Race, after all, is a social construct that correlates loosely with certain genetic patterns but is a poor stand-in for them. Two Black patients can have very different renin levels, very different bradykinin metabolism, and very different responses to lisinopril.

The genetic studies on angioedema risk illustrate this well. The XPNPEP2 variant that raises angioedema risk in Black men is carried by a minority, not by all Black men.⁹ The neprilysin variant linked to angioedema in African Americans similarly affects only some individuals.¹⁰ The bradykinin B2 receptor polymorphism linked to both cough and angioedema in South African patients is common enough to matter at a population level, but it does not affect everyone uniformly.¹¹

In principle, a genetic test could tell a clinician whether a specific patient is likely to have low renin, poor bradykinin clearance, or reduced nitric oxide availability, and guide drug choice accordingly. In practice, pharmacogenomic testing for hypertension drugs is not yet routine. For now, the guideline approach of using population-level data to inform first-line choices remains the standard, even as researchers work toward something more individualized.

Children and Adolescents

Most of the evidence on lisinopril and race comes from adult trials, but the question arises for younger patients too. A meta-analysis of six trials of ACE inhibitors in children examined whether racial differences in blood pressure response existed in pediatric populations.²³ The evidence base in children is much smaller than in adults, and pediatric hypertension management generally involves more individualized decision-making. Still, the physiological tendencies seen in adults, including lower renin levels and the potential for higher rates of cough, are present from a young age, so clinicians treating Black children and adolescents with hypertension tend to apply similar caution about ACE inhibitor monotherapy.

Pediatric patients also face the challenge of tolerability. A persistent dry cough in a teenager is likely to lead to medication abandonment faster than in an adult who understands the stakes. For children who do need an ACE inhibitor for kidney protection or other indications, monitoring for side effects and educating the family about what to watch for becomes especially important.