Losartan should be used with caution in patients with renal artery stenosis; Patients with volume depletion.
Reduced doses may be required in patients with renal impairment and should be considered in patients with hepatic impairment.
Serum-potassium concentrations should be monitored, especially in the elderly and patients with renal impairment, and the concomitant use of potassium-sparing diuretics should generally be avoided.
All patients receiving thiazide therapy should be observed for clinical signs of fluid or electrolyte imbalance: hyponatremia, hypochloremic alkalosis, and hypokalemia.
Thiazide therapy may impair glucose tolerance. Dosage adjustment of antidiabetic agents, including insulin, may be required.
Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving thiazide therapy. Because losartan decreases uric acid, losartan in combination with hydrochlorothiazide attenuates the diuretic-induced hyperuricemia.
Thiazides have been shown to increase the urinary excretion of magnesium; this may result in hypomagnesemia.
Increases in cholesterol and triglyceride levels may be associated with thiazide diuretic therapy.
Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose – galactose malabsorption should not take this medicine.
When pregnancy is detected, losartan should be discontinued as soon as possible. A decision should be made whether to discontinue nursing or discontinue the drug.
When driving vehicles or operating machinery it must be borne in mind that dizziness or drowsiness may occasionally occur when taking antihypertensive therapy, in particular during initiation of treatment or when the dose is increased.