Cozaar (losartan potassium) is an angiotensin II receptor blocker (ARB) prescription medication designed for the management of hypertension and the protection of renal function in patients with type 2 diabetes and proteinuria. It works by selectively blocking the binding of angiotensin II to the AT1 receptor, a key mechanism in the regulation of blood pressure and fluid balance. This targeted action results in vasodilation, a reduction in aldosterone secretion, and a subsequent decrease in systemic vascular resistance. Clinically, this translates to consistent blood pressure lowering and a demonstrated nephroprotective effect, making it a cornerstone therapy in modern cardiovascular and diabetic care protocols.

Features

• Active pharmaceutical ingredient: Losartan Potassium
• Drug class: Angiotensin II Receptor Blocker (ARB)
• Available in tablet formulations of 25 mg, 50 mg, and 100 mg
• Once-daily oral dosing for consistent 24-hour hemodynamic control
• Selective blockade of the AT1 receptor subtype
• Includes the active metabolite E-3174, which contributes significantly to its potent pharmacologic activity

Benefits

• Provides effective and sustained 24-hour blood pressure reduction, lowering the risk of stroke, myocardial infarction, and other cardiovascular events.
• Offers proven renal protection for patients with type 2 diabetes and established nephropathy, significantly slowing the progression of kidney disease.
• Demonstrates a favorable side effect profile, particularly a lower incidence of dry cough compared to ACE inhibitors.
• Contributes to a reduction in mortality and hospitalization rates in patients with heart failure when used as part of a comprehensive treatment plan.
• Helps to induce left ventricular hypertrophy regression, improving cardiac structure and function in hypertensive patients.
• Provides a well-tolerated therapeutic option with a low potential for metabolic disturbances such as hyperkalemia or hyperuricemia under appropriate monitoring.

Common use

Cozaar is primarily indicated for the first-line treatment of hypertension, either as monotherapy or in combination with other antihypertensive agents such as diuretics (e.g., hydrochlorothiazide). Its second major indication is for the treatment of diabetic nephropathy, characterized by elevated serum creatinine and proteinuria (>300 mg/day), in patients with type 2 diabetes mellitus and a history of hypertension. It is used to slow the progression of renal disease in this vulnerable patient population. Off-label, it may be used in the management of heart failure (particularly in patients intolerant of ACE inhibitors) and for the prevention of stroke in patients with hypertension and left ventricular hypertrophy.

Dosage and direction

The dosage of Cozaar must be individualized based on the patient’s condition and therapeutic response. For hypertension, the usual starting dose is 50 mg administered orally once daily. The dosage can be increased to a maximum of 100 mg once daily based on blood pressure response. A lower starting dose of 25 mg is recommended for patients with intravascular volume depletion (e.g., those treated with high-dose diuretics) or a history of hepatic impairment. For nephropathy in type 2 diabetic patients, the usual recommended dose is 50 mg once daily. This dose can be increased to 100 mg once daily based on blood pressure response. Cozaar may be administered with or without food. It is crucial to adhere to the prescribed dosing schedule to maintain consistent plasma drug levels.

Precautions

Prior to initiating and during therapy with Cozaar, several precautions must be observed. Hypotension: Symptomatic hypotension may occur, especially in volume-depleted patients (e.g., those on diuretic therapy). Correct volume depletion prior to administration. Renal Impairment: Changes in renal function, including acute renal failure, have been reported. Patients whose renal function may depend on the activity of the renin-angiotensin-aldosterone system (RAAS), such as those with renal artery stenosis, severe congestive heart failure, or post-kidney transplant, are at particular risk. Monitor renal function periodically. Hyperkalemia: Elevations in serum potassium can occur. Risk factors include renal impairment, diabetes, and concomitant use of potassium-sparing diuretics, potassium supplements, or salt substitutes containing potassium. Monitor potassium levels appropriately.

Contraindications

Cozaar is contraindicated in patients with a known hypersensitivity to losartan potassium or any component of the formulation. Do not co-administer with aliskiren in patients with diabetes. Concomitant use is contraindicated due to an increased risk of renal impairment, hypotension, and hyperkalemia. It is also contraindicated during the second and third trimesters of pregnancy, as drugs that act directly on the RAAS can cause injury and even death to the developing fetus.

Possible side effect

Like all medications, Cozaar can cause side effects, although not everybody gets them. The most common adverse reactions are generally mild and transient. Common side effects (>1%) include dizziness, upper respiratory infection (e.g., stuffy nose, sinusitis), nasal congestion, back pain, fatigue, cough, diarrhea, hypoglycemia in diabetics, and muscle cramps. Less common but more serious side effects require immediate medical attention and include symptoms of hyperkalemia (muscle weakness, slow/irregular heartbeat), signs of impaired renal function (change in amount of urine, swelling in feet/ankles), and severe allergic reactions (angioedema - swelling of the face, lips, throat, or tongue; difficulty breathing; hives). Angioedema is a rare but serious class-related side effect.

Drug interaction

Cozaar has the potential to interact with several other medications, which may alter its efficacy or increase the risk of adverse events.

• Other Blood Pressure Medications (Diuretics, Beta-blockers, Calcium Channel Blockers): Additive hypotensive effects. Dose adjustments may be necessary.
• Potassium-Sparing Diuretics (e.g., spironolactone, eplerenone), Potassium Supplements, Salt Substitutes: Increased risk of hyperkalemia.
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) (e.g., ibuprofen, naproxen): May reduce the antihypertensive effect of Cozaar and increase the risk of renal impairment.
• Lithium: Losartan may decrease lithium excretion, increasing lithium serum levels and the risk of lithium toxicity. Monitor lithium levels closely.
• Aliskiren: Contraindicated in patients with diabetes due to increased risk of renal impairment, hypotension, and hyperkalemia.

Missed dose

If a dose of Cozaar is missed, it should be taken as soon as it is remembered on the same day. However, if it is almost time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule resumed. Do not take a double dose to make up for a missed one. Maintaining a consistent daily routine is important for optimal blood pressure control.

Overdose

The most likely manifestation of a losartan overdose is hypotension and tachycardia; bradycardia could also occur from vagal stimulation. In the event of a suspected overdose, the patient should be placed in a supine position and immediate supportive treatment should be initiated. The degree of hypotension will guide therapy, which may include intravenous normal saline solution. Losartan and its active metabolite are not removed by hemodialysis.

Storage

Store Cozaar tablets at controlled room temperature, 20°C to 25°C (68°F to 77°F), in a dry place. Excursions are permitted between 15°C and 30°C (59°F and 86°F). Keep the medication in its original container, tightly closed, and out of the reach of children and pets. Do not use medication that is past its expiration date printed on the packaging. Properly discard any unused medication.

Disclaimer

This information is for educational and informational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The information provided is based on the drug’s prescribing information but may not be exhaustive.

Reviews

• “As a cardiologist with over 20 years of practice, I find Cozaar to be a reliable and well-tolerated agent in my antihypertensive arsenal. Its once-daily dosing and proven renal benefits in diabetic patients make it a frequent choice, especially for those who develop a cough on ACE inhibitors. The clinical trial data supporting its cardiorenal protective effects is robust.” – Dr. A. Reynolds, MD, FACC
• “I was switched to Cozaar 50 mg after experiencing a persistent cough on lisinopril. The transition was seamless. My blood pressure has been consistently well-controlled at my follow-up appointments (averaging 128/82 mmHg), and the troublesome cough resolved completely within two weeks. I have experienced no noticeable side effects.” – Patient T.S., 58
• “Managing hypertensive patients with chronic kidney disease is complex. Cozaar provides a critical tool by addressing both hypertension and offering specific renoprotection. I appreciate the flexibility in dosing and its generally favorable interaction profile. It remains a first-line option in evidence-based guidelines for this patient population.” – Nephrology Specialist, Dr. L. Chen
• “After my type 2 diabetes diagnosis and signs of early kidney issues, my endocrinologist started me on Cozaar. My recent tests showed a significant reduction in proteinuria, which was a huge relief. It’s reassuring to be on a medication that is actively protecting my kidneys while managing my blood pressure.” – Patient M.K., 64