Who Owns Cozaar?

Losartan was developed in the late 1980s and early 1990s by DuPont Pharmaceuticals. The compound was designed to selectively block the angiotensin II type 1 (AT1) receptor, which plays a key role in regulating blood pressure. By blocking this receptor, losartan causes blood vessels to dilate, reducing blood pressure.

The FDA approved Cozaar on April 14, 1995, making it the first angiotensin II receptor blocker available in the United States. The initial approval was for the treatment of hypertension, either alone or in combination with other antihypertensive medications. The European Medicines Agency granted approval in 1996 for EU member states.

The clinical evidence supporting Cozaar's approval came from dose-ranging studies in approximately 2,900 patients with essential hypertension. Subsequent trials expanded the drug's indications. The LIFE (Losartan Intervention For Endpoint reduction in hypertension) trial, published in The Lancet in 2002, demonstrated a 13% reduction in composite cardiovascular events compared to atenolol in patients with left ventricular hypertrophy. This trial was significant because it showed that Cozaar provided cardiovascular benefits beyond simple blood pressure reduction.

The FDA expanded Cozaar's indications to include diabetic nephropathy (kidney disease in patients with type 2 diabetes) and stroke risk reduction in patients with hypertension and left ventricular hypertrophy. In Europe, the drug also received approval for heart failure.

Cozaar was a major commercial success for Merck. At its peak in the mid-2000s, Cozaar generated over $3 billion in annual revenue. The drug was Merck's third-largest product during this period, behind Zocor and Fosamax. Cozaar's success helped establish the ARB class as a preferred treatment for hypertension, particularly for patients who could not tolerate ACE inhibitors due to cough side effects.

A combination product, Hyzaar (losartan/hydrochlorothiazide), was also marketed by Merck. Hyzaar combined losartan with a diuretic and was widely prescribed for patients requiring dual antihypertensive therapy. Hyzaar's patent also expired, and generic versions are available, though some combination products have faced intermittent supply issues.

Cozaar's U.S. patent expired in April 2010. Teva Pharmaceuticals launched the first generic losartan, followed by numerous other manufacturers. Generic competition rapidly eroded Cozaar's market share and revenue. By 2012, generic losartan accounted for the majority of prescriptions, and Merck's Cozaar revenue declined to under $500 million annually.

The nitrosamine contamination crisis that began in 2018 affected generic losartan products but not the brand-name Cozaar. Between 2018 and 2020, the FDA issued 49 voluntary recalls of generic losartan tablets from manufacturers including Torrent Pharmaceuticals, Hetero Labs, and Macleods Pharmaceuticals. The recalls were due to the detection of N-nitrosodimethylamine (NDMA) and N-nitroso-N-methyl-4-aminobutyric acid (NMBA), classified as probable human carcinogens, in the active pharmaceutical ingredient. The contamination originated from specific manufacturing processes at API suppliers in China and India.

As of 2026, losartan is not on the FDA Drug Shortage Database. Multiple generic manufacturers produce FDA-approved losartan, and the supply of plain losartan tablets is generally stable. The losartan/hydrochlorothiazide combination has experienced intermittent back-order issues with some manufacturers. The FDA's stricter nitrosamine testing requirements, finalized in 2023, have improved quality control across all ARB products.