Losartan potassium-hydrochlorothiazide has been evaluated for safety in 858 patients treated for essential hypertension and 3889 patients treated for hypertension and left ventricular hypertrophy. Most adverse reactions 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 events 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, adverse reactions occurring in greater than 2% of subjects treated with losartan-hydrochlorothiazide and at a greater rate than placebo were: back pain (2.1% vs 0.6%), dizziness (5.7% vs 2.9%), and upper respiratory infection (6.1% vs 4.6%).
The following additional adverse reactions have been reported in clinical trials with losartan-hydrochlorothiazide and/or the individual components: Blood and the lymphatic system disorders: Anemia, aplastic anemia, hemolytic anemia, leukopenia, agranulocytosis.
Metabolism and nutrition disorders: Anorexia, hyperglycemia, hyperuricemia, electrolyte imbalance including hyponatremia and hypokalemia.
Psychiatric disorders: Insomnia, restlessness.
Nervous system disorders: Dysgeusia, headache, migraine, paraesthesias.
Eye disorders: Xanthopsia, transient blurred vision.
Cardiac disorders: Palpitation, tachycardia.
Vascular disorders: Dose-related orthostatic effects, necrotizing angiitis (vasculitis, cutaneous vasculitis).
Respiratory, thoracic and mediastinal disorders: Nasal congestion.
Gastrointestinal disorders: Dyspepsia, abdominal pain, gastric irritation, cramping, nausea, vomiting, pancreatitis, sialoadenitis.
Hepato-biliary disorders: Jaundice (intrahepatic cholestatic jaundice).
Skin and subcutaneous tissue disorders: Rash, pruritus, purpura, toxic epidermal necrolysis, urticaria, photosensitivity, cutaneous lupus erythematosus.
Musculoskeletal and connective tissue disorders: Muscle cramps, muscle spasm.
Renal and urinary disorders: Glycosuria, renal dysfunction, interstitial nephritis, renal failure.
Reproductive system and breast disorders: Erectile dysfunction/impotence.
General disorders and administration site conditions: Chest pain, malaise, weakness.
Investigations: Liver function abnormalities.
Cough: Persistent dry cough has been associated with ACE-inhibitor use and in practice can be a cause of discontinuation of ACE-inhibitor therapy. Two prospective, parallel-group, double-blind, randomized, controlled trials were conducted to assess the effects of losartan on the incidence of cough in hypertensive patients who had experienced cough while receiving ACE-inhibitor therapy. Patients who had typical ACE-inhibitor cough when challenged with lisinopril, whose cough disappeared on placebo, were randomized to losartan 50 mg, lisinopril 20 mg, or either placebo (one study, n=97) or 25 mg hydrochlorothiazide (n=135). The double-blind treatment period lasted up to 8 weeks. The incidence of cough is shown in the following table. (See table.)

These studies demonstrate that the incidence of cough associated with losartan therapy, in a population that all had cough associated with ACE-inhibitor therapy, is similar to that associated with hydrochlorothiazide or placebo therapy.
Cases of cough, including positive re-challenges, have been reported with the use of losartan in postmarketing experience.
Postmarketing Experience: The following adverse reactions have been identified during post-approval use of HYZAAR, HYZAAR PLUS, and HYZAAR FORTE. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency reliably or to establish a causal relationship to drug exposure.
Digestive: Hepatitis has been reported rarely in patients treated with losartan.
Hematologic: Thrombocytopenia.
Hypersensitivity: Angioedema, including swelling of the larynx and glottis, causing airway obstruction and/or swelling of the face, lips, pharynx, and/or tongue. Vasculitis, including Henoch-Schönlein purpura; anaphylactic reactions which can present as respiratory distress (including pneumonitis and pulmonary edema).
Musculoskeletal: Rhabdomyolysis.
Skin: Erythroderma.
Non-melanoma Skin Cancer: Hydrochlorothiazide is associated with an increased risk of non-melanoma skin cancer. In a study conducted in the Sentinel System, increased risk was predominantly for squamous cell carcinoma (SCC) and in white patients taking large cumulative doses. The increased risk for SCC in the overall population was approximately 1 additional case per 16,000 patients per year, and for white patients taking a cumulative dose of ≥50,000mg the risk increase was approximately 1 additional SCC case for every 6,700 patients per year.
Eye disorders: Secondary acute angle-closure glaucoma, acute myopia, choroidal effusion.
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