Like angiotensin-converting enzyme (ACE) inhibitors, losartan interferes with the renin-angiotensin-aldosterone system by decreasing angiotensin II-mediated effects. Although losartan and ACE inhibitors have similar therapeutic potency, losartan reportedly has fewer adverse effects because of selective antagonism of angiotensin I receptors [1]. Schlienger and colleagues [2] recently described a patient in whom losartan induced reversible ageusia; we present two similar reports.

A 49-year-old woman had been using enalapril (10 mg/d) for the treatment of hypertension. Because of fatigue, therapy was changed to losartan (50 mg/d). One week after the initiation of therapy, the patient reported a persistent metallic taste, a tickling cough, and intestinal symptoms. After discontinuation of losartan therapy, symptoms disappeared. Concomitant medications were carbaspirin calcium (38 mg/d), cetirizine (10 mg/d), and ranitidine (150 mg three times daily).

A 69-year-old woman had been using perindopril (4 mg/d) for the treatment of hypertension. Because of a tickling cough, therapy was changed to losartan (10 mg/d). After 3 months, the patient developed a burning feeling on the tongue and a complete loss of taste. Perindopril therapy was restarted, and the taste disturbances disappeared within 1 week. Concomitant medications were bemetanide (1 mg three times daily) and acenocoumarole (1 mg) as prescribed.

The temporal association and the lack of suspected concomitant medication suggests a causal relation between dysgeusia and the use of losartan. We contacted the manufacturer and found that 11 cases of dysgeusia and 1 case of ageusia had been reported through a safety monitoring program. Dysgeusia is also associated with valsartan, another angiotensin II antagonist [3]. The mechanism underlying losartan-induced dysgeusia is unknown. Taste disturbances induced by ACE inhibitors have tentatively been ascribed to chelation of metal ions, such as zinc [4]. Losartan, however, is not known to have chelating properties. Our observation of dysgeusia during the use of losartan but not during the use of ACE inhibitors in the same patient suggests a different pharmacologic mechanism for the two phenomena.