Can Losartan Cause a Cough and What Should You Do?

Losartan causes cough at roughly the same rate as a sugar pill, making it one of the least likely blood pressure medications to trigger this side effect. In pooled clinical trials, about 3.1% of patients on losartan reported cough compared with 2.6% on placebo, a gap so small it may be statistical noise. That said, isolated case reports do exist, and the picture gets more complicated for people who switched to losartan specifically because another medication was making them cough. Understanding what is actually behind a new cough while taking losartan matters, because the cause changes what you should do about it.

Why Losartan Is Mechanically Different From ACE Inhibitors

The most common drug-related cough in blood pressure treatment comes from ACE inhibitors like lisinopril, enalapril, and ramipril. These drugs work by blocking an enzyme that produces a hormone called angiotensin II, which narrows blood vessels. The problem is that the same enzyme also breaks down bradykinin, substance P, and certain prostaglandins. When you block the enzyme, those substances build up in lung tissue, irritating sensory nerves and triggering the dry, ticklish cough that roughly one in ten ACE inhibitor users experiences.¹

Losartan belongs to a different class called angiotensin receptor blockers, or ARBs. Instead of blocking the enzyme that produces angiotensin II, losartan blocks the receptor that angiotensin II binds to. The enzyme itself keeps working normally, so bradykinin and the other irritating substances get broken down at their usual rate. In theory, this means no cough.² That theoretical advantage holds up well in practice, as the clinical data show, but “well” is not the same as “perfectly.”

What the Clinical Numbers Actually Show

Large pooled analyses from losartan’s clinical trial program put the cough rate at about 3%, which was essentially indistinguishable from the roughly 2.6% seen in patients taking placebo. By contrast, ACE inhibitors in the same datasets produced cough in about 8.8% of patients.¹ A systematic review and network meta-analysis comparing ACE inhibitors with other drug classes found that ACE inhibitors produced roughly three times more cough than ARBs overall.³

When researchers specifically recruited patients who had already developed a cough on an ACE inhibitor and then gave them losartan, the findings were reassuring. In a double-blind trial, the cough rate with losartan was about 29%, compared with 72% for lisinopril and 34% for hydrochlorothiazide, a simple diuretic with no known cough-triggering mechanism. The losartan cough rate was statistically similar to the diuretic, suggesting the coughs in the losartan group were mostly coincidental rather than drug-caused.⁴ A separate trial comparing losartan with lisinopril in cough-prone patients found that the cough rate on losartan, about 37%, did not significantly differ from placebo at about 31%, while lisinopril drove the rate up to nearly 88%.⁵

Those numbers are worth pausing on. Even among patients whose airways were already sensitized from previous ACE inhibitor use, losartan performed no worse than a drug with no plausible cough mechanism. That is strong evidence that losartan, as a class member of ARBs, does not meaningfully cause cough.

The Rare Cases Where Losartan Does Seem Responsible

Despite the favorable class data, you can find published case reports of patients developing a cough on losartan that went away when the drug was stopped. In one unusual case, a patient developed a cough three days after starting losartan, the cough persisted for the two weeks the patient remained on the drug, and it resolved completely within a week of switching to enalapril, which is itself an ACE inhibitor.⁶ That case is notable precisely because it runs against every expectation: the ACE inhibitor stopped the cough that the ARB started. The mechanism behind such paradoxical reactions remains unknown, and the case report’s authors acknowledged that the finding contradicts the general pharmacological understanding.

A separate analysis looked at patients who had stopped taking losartan due to cough and found that 91% of them had previously taken an ACE inhibitor, and 86% had experienced cough on that prior medication.⁷ That pattern suggests most of the cough reports attributed to losartan are actually carryover from earlier ACE inhibitor use, a lingering airway sensitivity, or the patient’s underlying tendency to cough being mistakenly blamed on the new drug. Some patients’ ACE inhibitor cough can take weeks to fully clear after stopping, so if you start losartan the same day you stop lisinopril, the old cough may seem like a new side effect from the new pill.

Other Common Reasons for a Persistent Cough

If you develop a cough while taking losartan, the odds strongly favor a cause unrelated to the medication. Chronic cough has a short list of common culprits, and none of them have anything to do with blood pressure drugs.

Postnasal drip: Sinus congestion, allergies, and chronic rhinitis produce mucus that drips down the back of the throat, triggering a cough reflex. This is one of the most frequent causes of ongoing cough in adults.
Acid reflux: Gastroesophageal reflux can irritate the throat and airway without causing the classic heartburn symptoms. A cough may be the only sign.
Asthma: Cough-variant asthma produces a dry cough without the typical wheezing or shortness of breath, making it easy to overlook.
Eosinophilic bronchitis: Airway inflammation driven by certain immune cells can cause chronic cough without the airflow obstruction seen in asthma.

These four conditions, alone or in combination, account for the vast majority of chronic coughs in adults, and any of them can be “clinically silent” apart from the cough itself, meaning the patient has no other obvious symptoms to point toward the real diagnosis.⁸ Reflux and postnasal drip in particular are extremely common in the same age group that takes blood pressure medication, so the overlap is easy to mistake for a drug effect.⁹

What You Should Do If You Develop a Cough on Losartan

The most important step is not to stop the medication on your own. Losartan is typically prescribed for a meaningful reason, whether that is high blood pressure, kidney protection, or heart failure management. Stopping suddenly can cause a rebound rise in blood pressure that carries its own risks. Instead, talk to your prescriber about the cough and work through a structured approach.

Your doctor will likely want to rule out the common non-drug causes first. If you have nasal congestion, post-meal throat clearing, or nighttime cough that worsens lying down, reflux or postnasal drip may be the answer. If you recently had a respiratory infection, the cough may be post-infectious and will resolve on its own over weeks. A trial of an antihistamine, a nasal steroid, or an acid-reducing medication can help pinpoint the cause without any medication change.

If non-drug causes are ruled out and the cough clearly started after beginning losartan, a reasonable next step is a supervised trial off the drug. Your doctor may switch you to a calcium channel blocker like amlodipine or a different ARB temporarily. If the cough disappears within one to four weeks and returns when losartan is restarted, that sequence is the strongest evidence that losartan was the actual cause. Without that rechallenge, attributing the cough to losartan is little more than a guess.

Switching From an ACE Inhibitor to Losartan for Cough

If you are reading this because you already have an ACE inhibitor cough and are wondering whether losartan is a good alternative, the evidence is squarely in your favor. The network meta-analysis mentioned earlier found that ARBs and calcium channel blockers are both reasonable options for patients who develop cough on ACE inhibitors.³ In head-to-head trials, losartan specifically produced cough rates no different from placebo in people with a history of ACE inhibitor cough.⁵

One practical point: be patient during the transition. ACE inhibitor cough can linger for one to four weeks after you stop the drug, because the accumulated bradykinin and related substances need time to clear. If you start losartan immediately and still have a cough two weeks later, that does not mean losartan is causing the same problem. Give it time. The analysis of patients who quit losartan for cough found that the overwhelming majority had prior ACE inhibitor cough histories, which suggests many of those discontinuations were premature.⁷

Losartan in People With Lung Disease

If you have a chronic lung condition like COPD, you might worry that any blood pressure drug that even occasionally causes cough could worsen your respiratory symptoms. A pilot study examined losartan specifically in patients with pulmonary hypertension secondary to COPD and found that the drug was well tolerated, with a safety profile comparable to placebo and no significant effect on blood gases.¹⁰ This was a small study, so it cannot be taken as a guarantee for all lung disease patients, but it is reassuring that losartan did not provoke respiratory problems even in a population with compromised airways.

When a Cough Is Not Just a Cough

There is a more serious, though much rarer, reaction to be aware of. Angioedema, a rapid swelling of deeper tissue that can affect the lips, tongue, throat, and face, occurs in roughly 0.1% of patients taking ARBs including losartan.¹¹ Unlike cough, angioedema can be dangerous when it involves the airway. Published cases describe a range of onset times. One report documented a 58-year-old man who developed lip and facial swelling six months after starting losartan, with symptoms that did not respond to antihistamines or corticosteroids and only resolved after the drug was discontinued and replaced with amlodipine.¹² Another case involved a 50-year-old man who developed angioedema in the setting of acute kidney disease while on losartan.¹³ A third case described a 75-year-old man who had been on losartan for 15 years before developing sudden tongue, neck, and face swelling.¹¹

The delayed onset is the tricky part. Angioedema from losartan can appear months or even years into therapy, which makes it easy for both patients and doctors to overlook the medication as the cause. If you experience any sudden swelling of your face, lips, or tongue while taking losartan, seek emergency medical care immediately, regardless of how long you have been on the drug. This is not a “wait and call your doctor Monday” situation.

Who Is More Susceptible to Drug-Related Cough

Research into why some people develop a cough on blood pressure medications while others do not has pointed toward genetics. A study examining ACE inhibitor-induced cough identified several gene variants that influence susceptibility. Variations in genes involved in breaking down bradykinin and in prostaglandin signaling pathways were associated with higher or lower cough risk. Interestingly, one variant in the ACE gene itself had opposite effects depending on sex: it was protective in men but increased the risk in women.¹⁴

These findings are specific to ACE inhibitor cough, not ARB cough, because ARBs do not operate through the same pathway. But they help explain a broader observation: women and people of East Asian descent are more likely to develop ACE inhibitor cough. If you are in one of those groups and experienced cough on an ACE inhibitor, you may have a genetic setup that makes your airways more sensitive to bradykinin buildup. Switching to losartan sidesteps that pathway entirely, which is precisely why the switch tends to work so well for those patients.

Why Side Effects Matter Beyond Discomfort

A persistent cough might seem like a minor annoyance compared with the cardiovascular risks that losartan is prescribed to manage, but side effects have a real downstream cost. A cross-sectional study of hypertensive patients found that those who experienced adverse drug reactions, including dry cough, were about seven times more likely to have poor medication adherence compared with those who did not experience side effects.¹⁵ Side effects also reduced patients’ self-reported quality of life. That is a meaningful finding: a cough that causes someone to skip doses or quietly stop their medication can do more long-term harm than the cough itself. If you are coughing and it is bothering you enough to consider quitting your medication, talking to your doctor about alternatives is almost always a better move than going it alone.

1
PubMed Central. Safety and tolerability of losartan potassium, an angiotensin II receptor antagonist, compared with hydrochlorothiazide, atenolol, felodipine ER, and angiotensin-converting enzyme inhibitors for the treatment of systemic hypertension
2
Elsevier / Clinical Therapeutics. Cough induced by losartan with resolution after substitution with enalapril
3
Europe PMC. Angiotensin-converting enzyme inhibitor induced cough compared with placebo, and other antihypertensives: A systematic review, and network meta-analysis
4
PubMed Central. Double-blind comparison of losartan, lisinopril and hydrochlorothiazide in hypertensive patients with a previous angiotensin converting enzyme inhibitor-associated cough
5
PubMed Central. Use of losartan in the treatment of hypertensive patients with a history of cough induced by angiotensin-converting enzyme inhibitors
6
PubMed Central. Cough induced by losartan with resolution after substitution with enalapril
7
Europe PMC. Cough and angiotensin II receptor antagonists: cause or confounding?
8
PubMed Central. Overview of common causes of chronic cough: ACCP evidence-based clinical practice guidelines
9
Europe PMC. Chronic cough, reflux, postnasal drip syndrome, and the otolaryngologist
10
PubMed Central. Pilot study of losartan for pulmonary hypertension in chronic obstructive pulmonary disease
11
CrossRef. LOSARTAN INDUCED ANGIO EDEMA: A RARE CASE REPORT
12
PubMed Central. Losartan-induced Angioedema: A Case Report and Review of Literature
13
Europe PMC. A Case Report of Losartan Induced Angioedema
14
PubMed Central. Identification of genetic factors associated with susceptibility to angiotensin-converting enzyme inhibitors-induced cough
15
SpringerLink. Exploring the association of adverse drug reactions with medication adherence and quality of life among hypertensive patients: a cross-sectional study