Lisinopril causes a dry, persistent cough because it allows a chemical called bradykinin to build up in your lungs and airways. This is the most common side effect of lisinopril and the entire class of drugs it belongs to, called ACE inhibitors. Somewhere between 5% and 14% of people who take these medications develop the cough, though some estimates run as high as 35%.
How Bradykinin Triggers the Cough
Lisinopril works by blocking an enzyme called ACE (angiotensin-converting enzyme). Blocking this enzyme lowers blood pressure, which is the whole point of the drug. But ACE has a second job: it breaks down bradykinin, a substance your body naturally produces. When you block ACE, bradykinin doesn’t get cleared the way it normally would. It accumulates in the tissue lining your airways.
Bradykinin irritates sensory nerve endings in the throat and lungs, triggering the cough reflex. Other inflammatory substances, including prostaglandins and a compound called substance P, also appear to play a role. Substance P is a signaling molecule that sensitizes your airways, making them more reactive. The combination of these chemicals essentially turns up the sensitivity of your cough reflex so that normal breathing, talking, or even a slight tickle in your throat can set off a coughing fit.
This is not an allergic reaction or a sign that the drug is harming your lungs. The same mechanism that causes the cough is actually part of how ACE inhibitors protect the heart and blood vessels. It’s an unavoidable side effect of the drug’s core action.
What the Cough Feels Like
The cough was first described in medical literature in 1985 as a “nasty dry cough,” and that description still holds. It’s persistent, nonproductive (meaning nothing comes up), and often described as a tickle or irritation in the back of the throat. Some people also notice mild upper respiratory symptoms alongside it. The cough tends to be worse at night or when lying down, and it can range from a mild annoyance to something that disrupts sleep and daily life.
What makes it tricky is timing. While it’s generally thought that the cough develops within the first month of starting the medication, research shows the average onset is actually around 5.7 months, with some people not developing it until nearly two years in. That delayed onset means many people don’t connect the cough to their blood pressure medication, especially if they’ve been taking it without problems for months.
Who Is Most Likely to Get It
Women develop this cough more often than men. People of East Asian descent, particularly Chinese populations, also appear to have a significantly higher susceptibility. One study comparing populations in different cities found that Chinese patients had both a higher incidence of the cough and a greater odds ratio for developing it, suggesting a genetic component to how the body handles bradykinin accumulation.
Interestingly, this heightened cough risk in Asian populations does not come with a higher risk of angioedema, which is a rarer and more serious swelling reaction to ACE inhibitors. The two side effects seem to involve different pathways despite both being linked to bradykinin.
How Long It Lasts After Stopping
If you stop taking lisinopril, the cough does go away, but not always immediately. On average, the cough persists for about 3 to 4 weeks after discontinuation. For lisinopril specifically, the mean duration is about 3.7 weeks, which is comparable to other ACE inhibitors like enalapril (3.1 weeks) and captopril (3.0 weeks). In rare cases, the cough can linger for up to 3 months.
This delay catches people off guard. If you stop lisinopril and the cough is still there a week later, that doesn’t mean the drug wasn’t causing it. Give it a full month before concluding the cough has a different cause.
Switching to a Different Medication
The standard approach when this cough becomes intolerable is switching to a different class of blood pressure medication called an ARB (angiotensin receptor blocker). ARBs lower blood pressure through a related but different mechanism that doesn’t cause bradykinin to accumulate. Clinical evidence consistently shows that ARBs do not cause this cough, even in people who developed it on an ACE inhibitor. The rate of cough with ARBs is essentially the same as with a placebo.
Switching from one ACE inhibitor to another (for example, from lisinopril to enalapril) generally does not help. The cough is a class-wide effect, not specific to lisinopril. Clinical guidelines recommend moving to an ARB or a completely different type of blood pressure drug rather than trying another ACE inhibitor.
Can Anything Reduce the Cough Without Switching?
A few approaches have been studied for people who want to stay on their ACE inhibitor despite the cough. The most interesting finding involves iron supplementation. In a small randomized, double-blind trial, patients who took 256 mg of ferrous sulfate daily for four weeks saw a significant reduction in their cough scores compared to a placebo group. The theory is that iron inhibits nitric oxide production in the airways, which is part of the chain reaction that bradykinin sets off.
Anti-inflammatory drugs like indomethacin and sulindac have also been tested, since prostaglandins contribute to the cough. Results have been mixed. A medication called cromolyn sodium, which blocks the activity of substance P, has shown some promise as well. None of these are considered reliable enough to be standard recommendations, but they suggest that for some people, the cough can be managed without stopping the ACE inhibitor entirely.
For many people, though, the simplest and most effective solution remains switching medications. The cough is not dangerous, but it significantly affects quality of life, and effective alternatives exist. About 2.5% of people on ACE inhibitors find the cough severe enough to stop the medication altogether.