Adverse effects with losartan have usually been mild and transient in nature and have not required discontinuation of therapy. The overall incidence of adverse effects reported with losartan was comparable to placebo.
In controlled clinical trials of essential hypertension, dizziness was the only drug-related adverse effect that occurred with an incidence greater than placebo in ≥1% of patients treated with losartan. In addition, dose-related orthostatic effects were seen in <1% of patients. Rarely, rash was reported, although the incidence in controlled clinical trials was less than placebo. In contrast to ACE inhibitors, losartan is not found to cause accumulation of bradykinin and so incidence of cough observed with losartan is significantly less as compared to ACE inhibitors and is not more than that observed with placebo in several clinical trials.