Losartan-Hydrochlorothiazide: Fetal Toxicity: Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations. Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure and death. When pregnancy is detected, discontinue HYZAAR as soon as possible. See PREGNANCY under Use in Pregnancy & Lactation.
Hypersensitivity: Angioedema. (See SIDE EFFECTS.)
Hepatic and Renal Impairment: HYZAAR/HYZAAR PLUS/HYZAAR FORTE is not recommended for patients with hepatic impairment or severe renal impairment (creatinine clearance ≤30 mL/min) (see DOSAGE & ADMINISTRATION).
Losartan: Renal Function Impairment: As a consequence of inhibiting the renin-angiotensin system, changes in renal function including renal failure have been reported in susceptible individuals; these changes in renal function may be reversible upon discontinuation of therapy.
Other drugs that affect the renin-angiotensin system may increase blood urea and serum creatinine in patients with bilateral renal artery stenosis or stenosis of the artery to a solitary kidney. Similar effects have been reported with losartan; these changes in renal function may be reversible upon discontinuation of therapy.
Increases in Serum Potassium: Concomitant use of other drugs that may increase serum potassium may lead to hyperkalemia (see INTERACTIONS).
Dual blockade of the renin-angiotensin-aldosterone system (RAAS): There is evidence that the concomitant use of ACE-inhibitors, angiotensin II receptor blockers or aliskiren increases the risk of hypotension, hyperkalaemia and decreased renal function (including acute renal failure). Dual blockade of RAAS through the combined use of ACE-inhibitors, angiotensin II receptor blockers or aliskiren is therefore not recommended (see INTERACTIONS).
If dual blockade therapy is considered absolutely necessary, this should only occur under specialist supervision and subject to frequent close monitoring of renal function, electrolytes and blood pressure.
ACE-inhibitors and angiotensin II receptor blockers should not be used concomitantly in patients with diabetic nephropathy.
Hydrochlorothiazide: Hypotension and electrolyte/fluid imbalance: As with all antihypertensive therapy, symptomatic hypotension may occur in some patients. Patients should be observed for clinical signs of fluid or electrolyte imbalance, e.g volume depletion, hyponatremia, hypochloremic alkalosis, hypomagnesemia or hypokalemia which may occur during intercurrent diarrhea or vomiting. Periodic determination of serum electrolytes should be performed at appropriate intervals in such patients.
Metabolic and endocrine effects: Thiazide therapy may impair glucose tolerance. Dosage adjustment of antidiabetic agents, including insulin, may be required (see INTERACTIONS).
Thiazides may decrease urinary calcium excretion and may cause intermittent and slight elevation of serum calcium. Marked hypercalcemia may be evidence of hidden hyperparathyroidism. Thiazides should be discontinued before carrying out tests for parathyroid function.
Increases in cholesterol and triglyceride levels may be associated with thiazide diuretic therapy.
Thiazide therapy may precipitate hyperuricemia and/or gout in certain patients. Because losartan decreases uric acid, losartan in combination with hydrochlorothiazide attenuates the diuretic-induced hyperuricemia.
Non-melanoma skin cancer: An increased risk of non-melanoma skin cancer (basal cell carcinoma [BCC] and squamous cell carcinoma [SCC]) with increasing cumulative dose of hydrochlorothiazide has been observed in epidemiological studies. Photosensitizing actions of hydrochlorothiazide could act as a possible mechanism for non-melanoma skin cancer.
Patients taking hydrochlorothiazide should be informed of the risk of non-melanoma skin cancer and advised to take preventive measures to reduce sun and artificial UVA exposure. Patients should regularly check their skin for new lesions and promptly report suspicious skin lesions to their physicians for evaluation. The use of hydrochlorothiazide may also need to be reconsidered in patients who have experienced previous non-melanoma skin cancer. (See also SIDE EFFECTS.)
Other: In patients receiving thiazides, hypersensitivity reactions may occur with or without a history of allergy or bronchial asthma. Exacerbation or activation of systemic lupus erythematosus has been reported with the use of thiazides.
RACE: Based on the LIFE (Losartan Intervention For Endpoint reduction in hypertension) study, the benefits of losartan on cardiovascular morbidity and mortality compared to atenolol do not apply to Black patients with hypertension and left ventricular hypertrophy although both treatment regimens effectively lowered blood pressure in Black patients. In the overall LIFE study population (n=9193), treatment with losartan resulted in a 13.0% risk reduction (p=0.021) as compared to atenolol for patients reaching the primary composite endpoint of the combined incidence of cardiovascular death, stroke and myocardial infarction. In this study, losartan decreased the risk of cardiovascular morbidity and mortality compared to atenolol in non-Black, hypertensive patients with left ventricular hypertrophy (n=8660) as measured by the primary endpoint of the combined incidence of cardiovascular death, stroke and myocardial infarction (p=0.003). In this study, however, Black patients treated with atenolol were at lower risk of experiencing the primary composite endpoint compared with Black patients treated with losartan (p=0.03). In the subgroup of Black patients (n=533, 6% of the LIFE study patients), there were 29 primary endpoints among 263 patients on atenolol (11%, 25.9/1000 patient-years) and 46 primary endpoints among 270 patients (17%, 41.8/1000 patient-years) on losartan.
Use in Children: Safety and effectiveness in children have not been established.
Neonates with a history of in utero exposure to HYZAAR: If oliguria or hypotension occur, direct attention toward support of blood pressure and renal perfusion. Exchange transfusions or dialysis may be required as a means of reversing hypotension and/or substituting for disordered renal function.
Use in the Elderly: In clinical studies, there were no clinically significant differences in the efficacy and safety profiles of losartan-hydrochlorothiazide in older (≥65 years) and younger patients (<65 years).