Losartan potassium-hydrochlorothiazide has been evaluated for safety in 858 patients treated for essential hypertension. In clinical trials with losartan potassium-hydrochlorothiazide, no adverse experiences peculiar to this combination have been observed. Adverse experiences have been limited to those that were reported previously with losartan potassium and/ or hydrochlorothiazide. The overall incidence of adverse experiences reported with the combination was comparable to placebo.
In general, treatment with losartan potassium-hydrochlorothiazide was well tolerated. For the most part, adverse experiences have been mild and transient in nature and have not required discontinuation of therapy. In controlled clinical trials, discontinuation of therapy due to clinical adverse experiences was required in only 2.8% and 2.3% of patients treated with the combination and placebo, respectively. In these double-blind controlled clinical trials, the following adverse experiences reported with losartan-hydrochlorothiazide occurred in 1 percent of patients, and more often on drug than placebo, regardless of drug relationship:
The following adverse events were also reported at a rate of 1% or greater, but were as, or more, common in the placebo group: asthenia/ fatigue, diarrhea, nausea, headache, bronchitis, pharyngitis.
Adverse events occurred at about the same rates in men and women, older and younger patients, and Black and non-Black patients. A patient with known hypersensitivity to aspirin and penicillin, when treated with losartan potassium, was withdrawn from study due to swelling of the lips and eyelids and facial rash, reported as angioedema, which returned to normal 5 days after therapy was discontinued. Superficial peeling of palms and hemolysis were reported in one subject treated with losartan potassium.
Female patients of childbearing age should be told about the consequences of second-and third-trimester exposure to drugs that act on the renin-angiotensin system, and they should also be told that these consequences do not appear to have resulted from intrauterine drug exposure that has been limited to the first trimester. These patients should be asked to report pregnancies to their physicians as soon as possible.
A patient receiving HYZAAR should be cautioned that lightheadedness can occur, especially during the first days of therapy, and that it should be reported to the prescribing physician. The patients should be told that if syncope occurs, HYZAAR should be discontinued until the physician has been consulted. All patients should be cautioned that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to an excessive fall in blood pressure, with the same consequences of lightheadedness and possible syncope.
A patient receiving HYZAAR should be told not to use potassium supplements or salt substitutes containing potassium without consulting the prescribing physician (see PRECAUTIONS, Drug Interactions, Losartan Potassium).