Ambrisentan Tablets and Losartan Potassium

• Generic Name: ambrisentan
• Dosage Forms: tablet, film coated
• Other Brand Names: Letairis

Ambrisentan lowers blood pressure in your lungs, helping your heart pump blood more efficiently.

Ambrisentan is used to treat pulmonary arterial hypertension (PAH) in adults. It improves your ability to exercise and prevents your condition from getting worse. Ambrisentan is sometimes used with a medicine called tadalafil (Adcirca).

For women, ambrisentan is available only from a certified pharmacy under a special program. You must be registered in the program and sign agreements to use birth control and undergo pregnancy and blood testing.

Ambrisentan may also be used for purposes not listed in this medication guide.

• Generic Name: losartan
• Dosage Forms: n.a.
• Other Brand Names: Cozaar

Management of hypertension (alone or in combination with other classes of antihypertensive agents, including diuretics).

Angiotensin II receptor antagonists are recommended as one of several preferred agents for the initial management of hypertension according to current evidence-based hypertension guidelines; other preferred options include ACE inhibitors, calcium-channel blockers, and thiazide diuretics. While there may be individual differences with respect to recommendations for initial drug selection and use in specific patient populations, current evidence indicates that these antihypertensive drug classes all generally produce comparable effects on overall mortality and cardiovascular, cerebrovascular, and renal outcomes.

Individualize choice of therapy; consider patient characteristics (e.g., age, ethnicity/race, comorbidities, cardiovascular risk) as well as drug-related factors (e.g., ease of administration, availability, adverse effects, cost).

A 2017 ACC/AHA multidisciplinary hypertension guideline classifies BP in adults into 4 categories: normal, elevated, stage 1 hypertension, and stage 2 hypertension.

Whelton PK, Carey RM, Aronow WS et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. 2018;71:e13-115.

Individuals with SBP and DBP in 2 different categories (e.g., elevated SBP and normal DBP) should be designated as being in the higher BP category (i.e., elevated BP).

The goal of hypertension management and prevention is to achieve and maintain optimal control of BP. However, the BP thresholds used to define hypertension, the optimum BP threshold at which to initiate antihypertensive drug therapy, and the ideal target BP values remain controversial.

The 2017 ACC/AHA hypertension guideline generally recommends a target BP goal (i.e., BP to achieve with drug therapy and/or nonpharmacologic intervention) <130/80 mm Hg in all adults regardless of comorbidities or level of atherosclerotic cardiovascular disease (ASCVD) risk. In addition, an SBP goal of <130 mm Hg is recommended for noninstitutionalized ambulatory patients ≥65 years of age with an average SBP of ≥130 mm Hg. These BP goals are based upon clinical studies demonstrating continuing reduction of cardiovascular risk at progressively lower levels of SBP.

Previous hypertension guidelines generally have based target BP goals on age and comorbidities. Guidelines such as those issued by the JNC 8 expert panel generally have targeted a BP goal of <140/90 mm Hg regardless of cardiovascular risk and have used higher BP thresholds and target BPs in elderly patients compared with those recommended by the 2017 ACC/AHA hypertension guideline.

Some clinicians continue to support previous target BPs recommended by JNC 8 due to concerns about the lack of generalizability of data from some clinical trials (e.g., SPRINT study) used to support the current ACC/AHA hypertension guideline and potential harms (e.g., adverse drug effects, costs of therapy) versus benefits of BP lowering in patients at lower risk of cardiovascular disease.

Consider potential benefits of hypertension management and drug cost, adverse effects, and risks associated with the use of multiple antihypertensive drugs when deciding a patient’s BP treatment goal.

For decisions regarding when to initiate drug therapy (BP threshold), the 2017 ACC/AHA hypertension guideline incorporates underlying cardiovascular risk factors. ASCVD risk assessment recommended by ACC/AHA for all adults with hypertension.

ACC/AHA currently recommend initiation of antihypertensive drug therapy in addition to lifestyle/behavioral modifications at an SBP ≥140 mm Hg or DBP ≥90 mm Hg in adults who have no history of cardiovascular disease (i.e., primary prevention) and a low ASCVD risk (10-year risk <10%).

For secondary prevention in adults with known cardiovascular disease or for primary prevention in those at higher risk for ASCVD (10-year risk ≥10%), ACC/AHA recommend initiation of antihypertensive drug therapy at an average SBP ≥130 mm Hg or an average DBP ≥80 mm Hg.

Adults with hypertension and diabetes mellitus, chronic kidney disease (CKD), or age ≥65 years are assumed to be at high risk for cardiovascular disease; ACC/AHA state that such patients should have antihypertensive drug therapy initiated at a BP ≥130/80 mm Hg.

In stage 1 hypertension, experts state that it is reasonable to initiate drug therapy using the stepped-care approach in which one drug is initiated and titrated and other drugs are added sequentially to achieve the target BP. Initiation of antihypertensive therapy with 2 first-line agents from different pharmacologic classes recommended in adults with stage 2 hypertension and average BP >20/10 mm Hg above BP goal.

Black hypertensive patients generally tend to respond better to monotherapy with calcium-channel blockers or thiazide diuretics than to angiotensin II receptor antagonists. However, the combination of an ACE inhibitor or an angiotensin II receptor antagonist with a calcium-channel blocker or thiazide diuretic produces similar BP lowering in black patients as in other racial groups.

Angiotensin II receptor antagonists or ACE inhibitors may be particularly useful in hypertensive patients with diabetes mellitus or CKD; angiotensin II receptor antagonists also may be preferred, as an alternative to ACE inhibitors, in hypertensive patients with heart failure or ischemic heart disease and/or post-MI.

Prevention of Cardiovascular Morbidity and Mortality

Reduction of the risk of stroke in patients with hypertension and left ventricular hypertrophy.

Evidence suggests that the benefit associated with such losartan-based antihypertensive therapy does not apply to black patients.

Preliminary evidence suggests that aspirin therapy at baseline in patients receiving losartan may reduce the risk of combined cardiovascular death, stroke, and acute MI compared with aspirin therapy at baseline in patients receiving atenolol.

Diabetic Nephropathy

Management of diabetic nephropathy manifested by elevated Scr and proteinuria (urinary albumin to creatinine ratio ≥300 mg/g) in patients with type 2 diabetes mellitus and hypertension.

A recommended agent in the management of patients with diabetes mellitus and persistent albuminuria who have modestly elevated (30–300 mg/24 hours) or higher (>300 mg/24 hours) levels of urinary albumin excretion; slows rate of progression of renal disease in such patients.

Heart Failure

Angiotensin II receptor antagonists have been used in the management of heart failure.

Because of their established benefits, ACE inhibitors have been the preferred drugs for inhibition of the renin-angiotensin-aldosterone (RAA) system in patients with heart failure and reduced left ventricular ejection fraction (LVEF); however, some evidence indicates that therapy with an ACE inhibitor (enalapril) may be less effective than angiotensin receptor-neprilysin inhibitor (ARNI) therapy (e.g., sacubitril/valsartan) in reducing cardiovascular death and heart failure-related hospitalization.

Angiotensin II receptor antagonists may be used as an alternative for those patients in whom an ACE inhibitor or ARNI is inappropriate.

ACCF, AHA, and the Heart Failure Society of America (HFSA) recommend that patients with chronic symptomatic heart failure and reduced LVEF (NYHA class II or III) who are able to tolerate an ACE inhibitor or angiotensin II receptor antagonist be switched to therapy containing an ARNI to further reduce morbidity and mortality.