Hyzaar

Hyzaar is a prescription medication used to treat high blood pressure. It is also used to reduce the risk of stroke in patients with high blood pressure and left ventricular hypertrophy.

It is a single product containing 2 medications: losartan and hydrochlorothiazide. Losartan is in a class of medications called angiotensin II receptor antagonists. It works by blocking the action of certain natural substances that tighten blood vessels, allowing the blood to flow more smoothly and the heart to pump more efficiently. Hydrochlorothiazide is in a class of medications called diuretics, or "water pills." It works by causing the kidneys to get rid of unneeded water and salt from the body into the urine.

This medication comes in tablet form and is taken up to twice daily, with or without food.

Common side effects of Hyzaar include upper respiratory infection, back pain, and rash. It can also cause dizziness. Do not drive or operate heavy machinery until you know how Hyzaar affects you.

Serious side effects have been reported with Hyzaar including the following:

• Injury or death of unborn babies
• Allergic Reaction. Symptoms of an allergic reaction are swelling of the face, lips, throat, or tongue. Get emergency medical help right away and stop taking Hyzaar.
• Low blood pressure (hypotension). Low blood pressure may cause you to feel faint or dizzy. Lie down if you feel faint or dizzy.  Call your doctor right away.  
• A new or worsening condition called systemic lupus erythematosus.
• If you have kidney problems, you may see a worsening in how well your kidneys work. Call your doctor if you get swelling in your feet, ankles, or hands, or unexplained weight gain.
• If you have liver problems, you may see a worsening in how well your liver works. Call your doctor if you get nausea, pain in the right upper stomach area (abdomen), yellow eyes or skin (which can be itchy).
• Eye problems. One of the medicines in Hyzaar can cause eye problems that, if left untreated, may lead to vision loss.  Symptoms of eye problems can happen within hours to weeks of starting Hyzaar. Tell your doctor right away if you have:
  • decrease in vision
  • eye pain

Do not take Hyzaar if you:

• are allergic to Hyzaar or to any of its ingredients
• are allergic to any sulfonamide-containing medicines ("sulfa"). Ask your doctor if you are not sure what "sulfa" medicines are
• are not passing urine
• have diabetes and are taking a medicine called aliskiren to reduce blood pressure

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is unknown whether losartan is excreted in human milk, but significant levels of losartan and its active metabolite were shown to be present in rat milk. Hydrochlorothiazide appears in human milk. Because of the potential for adverse effects on the nursing infant, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.

This medicine may cause dizziness, lightheadedness, or fainting, especially when you get up suddenly from a lying or sitting position. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy. If you feel dizzy, lie down so you do not faint. Then sit for a few moments before standing to prevent the dizziness from returning.

Check with your doctor right away if you become sick while taking this medicine, especially if you have severe or continuing nausea or vomiting, or diarrhea that does not stop. These conditions may cause you to lose too much water and may lead to low blood pressure. You can also lose water by sweating, so drink plenty of water during exercise or in hot weather.

Check with your doctor immediately if blurred vision, difficulty reading, eye pain, or any other change in vision occurs during or after treatment. This could be a sign of a serious eye problem. Your doctor may want an eye doctor to check your eyes.

This medicine may affect blood sugar levels. Diabetic patients may notice a change in the results of blood or urine glucose tests. Talk to your doctor if you have any questions.

Ask your doctor before you use medicines, supplements, or salt substitutes that contain potassium.

Drinking alcohol or taking narcotic pain relievers or sleeping pills with this medicine may intensify feeling lightheaded, dizzy, or faint. Tell your doctor if you are drinking alcohol or using pain relievers or sleeping pills.

Do not take other medicines unless they have been discussed with your doctor. This especially includes prescription or nonprescription (over-the-counter [OTC]) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, and herbal or vitamin supplements.

• It is used to treat high blood pressure.
• It is used to prevent strokes.
• It may be given to you for other reasons. Talk with the doctor.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

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 Hyzaar 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, pharyngitis, sinus disorder, respiratory distress (including pneumonitis and pulmonary edema).

Gastrointestinal disorders: Dyspepsia, abdominal pain, gastric irritation, cramping, diarrhea, constipation, 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, myalgia, arthralgia.

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, edema/swelling, malaise, fever, 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 Table 1 below.

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. 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 has been reported rarely in patients treated with losartan; some of these patients previously experienced angioedema with other drugs including ACE inhibitors. Vasculitis, including Henoch-Schönlein purpura, has been reported with losartan. Anaphylactic reactions have been reported.

Musculoskeletal: rhabdomyolysis

Skin: Erythroderma

Pregnancy

Pregnancy Category D

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 losartan as soon as possible. These adverse outcomes are usually associated with use of these drugs in the second and third trimester of pregnancy. Most epidemiologic studies examining fetal abnormalities after exposure to antihypertensive use in the first trimester have not distinguished drugs affecting the renin-angiotensin system from other antihypertensive agents. Appropriate management of maternal hypertension during pregnancy is important to optimize outcomes for both mother and fetus.

In the unusual case that there is no appropriate alternative to therapy with drugs affecting the renin-angiotensin system for a particular patient, apprise the mother of the potential risk to the fetus. Perform serial ultrasound examinations to assess the intra-amniotic environment. If oligohydramnios is observed, discontinue Hyzaar, unless it is considered lifesaving for the mother. Fetal testing may be appropriate, based on the week of pregnancy. Patients and physicians should be aware, however, that oligohydramnios may not appear until after the fetus has sustained irreversible injury. Closely observe infants with histories of in utero exposure to Hyzaar for hypotension, oliguria, and hyperkalemia [see Use in Specific Populations (8.4)].

There was no evidence of teratogenicity in rats or rabbits treated with a maximum losartan potassium dose of 10 mg/kg/day in combination with 2.5 mg/kg/day of hydrochlorothiazide. At these dosages, respective exposures (AUCs) of losartan, its active metabolite, and hydrochlorothiazide in rabbits were approximately 5, 1.5, and 1.0 times those achieved in humans with 100 mg losartan in combination with 25 mg hydrochlorothiazide. AUC values for losartan, its active metabolite and hydrochlorothiazide, extrapolated from data obtained with losartan administered to rats at a dose of 50 mg/kg/day in combination with 12.5 mg/kg/day of hydrochlorothiazide, were approximately 6, 2, and 2 times greater than those achieved in humans with 100 mg of losartan in combination with 25 mg of hydrochlorothiazide. Fetal toxicity in rats, as evidenced by a slight increase in supernumerary ribs, was observed when females were treated prior to and throughout gestation with 10 mg/kg/day losartan in combination with 2.5 mg/kg/day hydrochlorothiazide. As also observed in studies with losartan alone, adverse fetal and neonatal effects, including decreased body weight, renal toxicity, and mortality, occurred when pregnant rats were treated during late gestation and/or lactation with 50 mg/kg/day losartan in combination with 12.5 mg/kg/day hydrochlorothiazide. Respective AUCs for losartan, its active metabolite and hydrochlorothiazide at these dosages in rats were approximately 35, 10 and 10 times greater than those achieved in humans with the administration of 100 mg of losartan in combination with 25 mg hydrochlorothiazide. When hydrochlorothiazide was administered without losartan to pregnant mice and rats during their respective periods of major organogenesis, at doses up to 3000 and 1000 mg/kg/day, respectively, there was no evidence of harm to the fetus.

Thiazides cross the placental barrier and appear in cord blood. There is a risk of fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults.

Nursing Mothers

It is not known whether losartan is excreted in human milk, but significant levels of losartan and its active metabolite were shown to be present in rat milk. Thiazides appear in human milk. Because of the potential for adverse effects on the nursing infant, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use

Safety and effectiveness of Hyzaar in pediatric patients have not been established.

Neonates with a history of in utero exposure to Hyzaar: If oliguria or hypotension occurs, direct attention toward support of blood pressure and renal perfusion. Exchange transfusion or dialysis may be required as means of reversing hypotension and/or substituting for disordered renal function.

Geriatric Use

In a controlled clinical study for the reduction in the combined risk of cardiovascular death, stroke and myocardial infarction in hypertensive patients with left ventricular hypertrophy, 2857 patients (62%) were 65 years and over, while 808 patients (18%) were 75 years and over. In an effort to control blood pressure in this study, patients were coadministered losartan and hydrochlorothiazide 74% of the total time they were on study drug. No overall differences in effectiveness were observed between these patients and younger patients. Adverse events were somewhat more frequent in the elderly compared to non-elderly patients for both the losartan-hydrochlorothiazide and the control groups [see Clinical Pharmacology (12.3)].

Race

In the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study, Black patients with hypertension and left ventricular hypertrophy treated with atenolol had a lower risk of stroke, the primary composite endpoint, as compared with Black patients treated with losartan (both cotreated with hydrochlorothiazide in the majority of patients). 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%, 26 per 1000 patient-years) and 46 primary endpoints among 270 patients (17%, 42 per 1000 patient-years) on losartan. This finding could not be explained on the basis of differences in the populations other than race or on any imbalances between treatment groups. In addition, blood pressure reductions in both treatment groups were consistent between Black and non-Black patients. Given the difficulty in interpreting subset differences in large trials, it cannot be known whether the observed difference is the result of chance. However, the LIFE study provides no evidence that the benefits of losartan on reducing the risk of cardiovascular events in hypertensive patients with left ventricular hypertrophy apply to Black patients [see Clinical Pharmacology (12.3)].

Hepatic Impairment

Initiation of Hyzaar is not recommended for patients with hepatic impairment because the appropriate starting dose of losartan, 25 mg, is not available.

Renal Impairment

Changes in renal function have been reported in susceptible individuals [see Dosage and Administration (2.1), Warnings and Precautions (5.4), and Clinical Pharmacology (12.3)]. Safety and effectiveness of Hyzaar in patients with severe renal impairment (creatine clearance <30 mL/min) have not been established.

Losartan Potassium

Significant lethality was observed in mice and rats after oral administration of 1000 mg/kg and 2000 mg/kg, respectively, about 44 and 170 times the maximum recommended human dose on a mg/m2 basis.

Limited data are available in regard to overdosage in humans. The most likely manifestation of overdosage would be hypotension and tachycardia; bradycardia could occur from parasympathetic (vagal) stimulation. If symptomatic hypotension should occur, supportive treatment should be instituted.

Neither losartan nor its active metabolite can be removed by hemodialysis.

Hydrochlorothiazide

The oral LD50 of hydrochlorothiazide is greater than 10 g/kg in both mice and rats. The most common signs and symptoms observed are those caused by electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis. If digitalis has also been administered, hypokalemia may accentuate cardiac arrhythmias. The degree to which hydrochlorothiazide is removed by hemodialysis has not been established.

Usual Adult Dose for Hypertension:

HYPERTENSION:
Hydrochlorothiazide 12.5 to 25 mg-Losartan 50 to 100 mg orally once a day

Maximum dose: Hydrochlorothiazide 25 mg-Losartan 100 mg orally once a day

Comments:
-A patient whose blood pressure is not adequately controlled with hydrochlorothiazide or losartan monotherapy may be switched to hydrochlorothiazide 12.5 mg-losartan 50 mg orally once a day.
-May increase dose if blood pressure remains uncontrolled after about 3 weeks.

Use: Treatment of hypertension. This drug is not indicated for initial therapy except when hypertension is severe enough that the benefit of achieving prompt blood pressure control exceeds the risk of initiating combination therapy.

SEVERE HYPERTENSION:
Initial treatment: Hydrochlorothiazide 12.5 mg-Losartan 50 mg orally once a day; if blood pressure remains uncontrolled after 2 to 4 weeks, may initiate maximum dose.

Maximum dose: Hydrochlorothiazide 25 mg-Losartan 100 mg orally once a day

HYPERTENSION WITH LEFT VENTRICULAR HYPERTROPHY:
Initial therapy: Losartan monotherapy; if blood pressure remains uncontrolled, may initiate this drug.

Add-on therapy: Hydrochlorothiazide 12.5 mg-Losartan 50 mg orally once a day; if blood pressure remains uncontrolled, initiate hydrochlorothiazide 12.5 mg-losartan 100 mg orally once a day, followed by hydrochlorothiazide 25 mg-losartan 100 mg orally once a day, if needed.

Use: To reduce the risk of stroke in patients with hypertension and left ventricular hypertrophy, but there is evidence that this benefit does not apply to Black patients.

More frequent side effects include: dizziness. See below for a comprehensive list of adverse effects.