Can Losartan Cause A Cough

Can Losartan Cause a Cough?

Introduction to Losartan and Cough

Losartan is an angiotensin II receptor antagonist commonly prescribed for hypertension. Unlike angiotensin-converting enzyme (ACE) inhibitors, which are well-known for causing cough in some patients, losartan is generally considered less likely to induce this side effect. However, there are instances where losartan has been associated with cough, raising questions about its safety profile in this regard.

Comparative Studies on Cough Incidence

Losartan vs. ACE Inhibitors

Several studies have compared the incidence of cough in patients treated with losartan versus those treated with ACE inhibitors like lisinopril. In a multicenter, randomized, double-blind trial involving 135 patients with a history of ACE inhibitor-related cough, the incidence of cough was significantly lower in patients treated with losartan (29%) compared to those treated with lisinopril (72%) . This suggests that losartan is a safer alternative for patients who develop a cough with ACE inhibitors.

Losartan vs. Other Antihypertensives

In another study, the incidence of cough in patients treated with losartan was found to be similar to that in patients treated with hydrochlorothiazide, a diuretic, and significantly lower than in those treated with lisinopril . This further supports the notion that losartan is less likely to cause cough compared to ACE inhibitors.

Mechanisms Behind Cough Induction

ACE Inhibitors and Bradykinin

The cough associated with ACE inhibitors is believed to be due to the accumulation of bradykinin, substance P, and prostaglandins, which are not broken down due to the inhibition of ACE . This mechanism is not applicable to losartan, which does not inhibit ACE and therefore should theoretically not cause cough.

Losartan and Cough

Despite the lower incidence, there are documented cases where losartan has induced cough. For instance, a case study reported a 23-year-old woman who developed a cough after starting losartan, which resolved after switching to the ACE inhibitor enalapril. Another case involved a 49-year-old woman who experienced a severe dry cough after starting losartan, which disappeared after discontinuing the drug. These cases suggest that while rare, losartan can still cause cough in some individuals.

Conclusion

While losartan is generally associated with a lower incidence of cough compared to ACE inhibitors, it is not entirely free from this side effect. The majority of studies indicate that losartan is a safer alternative for patients who develop a cough with ACE inhibitors. However, healthcare providers should remain vigilant and consider individual patient responses when prescribing losartan.

Summary

Consensus Meter