Losartan is an angiotensin II receptor blocker (ARB) used to manage high blood pressure and protect organs from the long-term damage caused by hypertension. By selectively blocking the AT1 receptor, losartan prevents angiotensin II from tightening blood vessels and signaling the kidneys to retain salt and water. The result is blood vessel relaxation, reduced vascular resistance, and lower blood pressure.
Unlike ACE inhibitors, ARBs such as losartan do not significantly increase bradykinin levels, which is why losartan has a lower risk of persistent dry cough. Many patients who cannot tolerate an ACE inhibitor switch to an ARB for comparable blood pressure control and cardio-renal protection. Losartan’s active metabolite (EXP3174) contributes to its clinical effect, and the medication is available in generic forms and as combinations with diuretics (e.g., losartan/hydrochlorothiazide) to enhance blood pressure control when needed.
Beyond lowering blood pressure, losartan has evidence supporting kidney protection in diabetes and reduction in stroke risk in certain patients with left ventricular hypertrophy. These benefits stem from both hemodynamic effects and favorable impacts on the renin-angiotensin-aldosterone system (RAAS), making losartan a cornerstone in cardiovascular risk reduction strategies.
Losartan is primarily prescribed for hypertension (high blood pressure) in adults and in children 6 years and older. Effective blood pressure control reduces the risk of heart attack, stroke, heart failure, kidney failure, and vision loss over time. Doctors may choose losartan as first-line therapy or as part of a combination regimen when blood pressure goals are not met with a single medication.
Losartan is also used to help protect the kidneys in adults with type 2 diabetes and proteinuria (diabetic nephropathy). In select adults with left ventricular hypertrophy (LVH), losartan can lower stroke risk. Clinicians sometimes use losartan in heart failure patients who cannot tolerate ACE inhibitors, and in certain cases where RAAS blockade is indicated for cardio-renal protection, based on individual risk-benefit assessment.
Your prescriber will tailor losartan dosing to your diagnosis, age, kidney and liver function, other medications, and blood pressure targets. Typical adult starting dose for hypertension is 50 mg once daily. Some patients—particularly those who are volume-depleted (due to diuretics, low salt intake, vomiting/diarrhea) or with hepatic impairment—may start at 25 mg once daily to reduce the risk of dizziness or low blood pressure. The usual maintenance range is 25–100 mg per day, given once daily or divided into twice-daily dosing based on response and tolerability.
For diabetic nephropathy, 50 mg once daily is commonly initiated and may be titrated to 100 mg once daily to maximize renal protective benefits and proteinuria reduction, if tolerated. In heart failure, dosing often starts at 25–50 mg once daily and can be carefully uptitrated (up to 150 mg/day in some evidence) with close monitoring of blood pressure, kidney function, and potassium levels.
Pediatric dosing for hypertension (ages 6–16) typically begins at 0.7 mg/kg once daily (up to 50 mg). Adjustments are made based on response and tolerability, and pediatric use requires careful oversight by a clinician experienced with antihypertensive therapy in children.
Administration tips: Take losartan at the same time each day, with or without food. Consistency improves blood pressure stability. If your regimen involves other antihypertensive agents (such as a thiazide diuretic or a calcium-channel blocker), your clinician may stagger doses to minimize side effects. Do not stop losartan abruptly without medical advice, as blood pressure may rise. Home blood pressure monitoring is encouraged; record morning and evening readings and share trends with your healthcare team for dose adjustments.
Kidney function and potassium need periodic checks. ARBs can modestly reduce glomerular filtration pressure; mild increases in creatinine may occur when therapy begins, especially in those with pre-existing kidney disease or renal artery stenosis. Clinicians typically monitor serum creatinine and potassium within 1–2 weeks of starting or changing dose. Notify your provider if you experience decreased urine output, unusual swelling, or muscle weakness (which can be a sign of high potassium).
People on salt substitutes or high-potassium diets should be cautious, as losartan can raise potassium levels. Dehydration from vomiting, diarrhea, or excessive sweating may precipitate low blood pressure—if you become acutely ill, ask your clinician whether to temporarily hold losartan (“sick day” protocol) until you are rehydrated. Dizziness is most likely when first starting or increasing the dose; stand up slowly and use caution when driving or operating machinery until you know how you respond.
Liver impairment can increase losartan exposure; lower starting doses are recommended in moderate hepatic impairment, and use in severe hepatic impairment requires individualized risk assessment. People of African ancestry may have slightly less blood pressure response to ARB monotherapy; combination therapy (e.g., with a thiazide diuretic) often restores robust effectiveness. Before surgery or procedures involving anesthesia, tell your care team you take losartan, as blood pressure may drop more than expected intraoperatively; your surgeon or anesthesiologist may advise holding a dose beforehand.
Do not use losartan during pregnancy. ARBs carry a boxed warning for fetal toxicity, especially in the second and third trimesters, and must be discontinued immediately if pregnancy is detected. Alternatives considered safer in pregnancy should be used instead. Breastfeeding considerations should be discussed with your clinician to weigh risks and benefits.
Losartan should not be used with aliskiren in patients with diabetes due to increased risks. Avoid combining losartan with another RAAS blocker (an ACE inhibitor) solely for diabetic nephropathy, as dual blockade raises the likelihood of kidney injury, hyperkalemia, and hypotension without clear outcome benefits. Hypersensitivity to losartan or any component of the formulation is a contraindication. Severe bilateral renal artery stenosis requires great caution and close monitoring if therapy is considered.
Most people tolerate losartan well. Common side effects are generally mild and often improve as your body adapts. The most frequently reported include dizziness or lightheadedness (especially after the first few doses), fatigue, stuffy nose or upper respiratory symptoms, and back pain. Compared with ACE inhibitors, losartan has a lower risk of chronic dry cough.
Clinically important effects to watch for include low blood pressure (faintness, blurred vision), kidney function changes (reduced urine output, swelling), and high potassium (muscle weakness, tingling, slow or irregular heartbeat). Your care team can adjust dose, add a diuretic, or modify diet to manage these issues.
Seek urgent care for signs of angioedema or severe allergic reaction, such as swelling of the face or throat, difficulty breathing, or sudden, widespread hives. Report persistent side effects to your prescriber; dose adjustments, timing changes, or switching to a different medication may resolve symptoms while maintaining blood pressure control.
Several medication classes can interact with losartan, affecting blood pressure, kidney function, or potassium levels. Always provide your prescriber and pharmacist with an up-to-date list of prescription drugs, over-the-counter products, vitamins, and herbal supplements.
Alcohol can amplify dizziness or drops in blood pressure. Some herbal products (e.g., licorice with glycyrrhizin) may raise blood pressure and counteract antihypertensive therapy; others (like high-dose potassium-containing supplements) may increase potassium. Share any nonprescription products with your healthcare team before starting losartan.
If you miss a dose of losartan, take it as soon as you remember the same day. If it is almost time for your next dose, skip the missed dose and resume your regular schedule. Do not double up to make up for a missed dose, as this may increase the risk of dizziness or low blood pressure. Setting phone reminders or using a pill organizer can help maintain consistency, which is key to sustained blood pressure control.
Symptoms of losartan overdose can include pronounced dizziness, fainting, very low blood pressure, rapid or slow heartbeat, and, rarely, kidney function changes. Immediate medical attention is essential: call emergency services or contact Poison Control at 1-800-222-1222 in the U.S. until professional help is available. Management is supportive—maintaining blood pressure, monitoring electrolytes and kidney function, and treating symptoms. Do not attempt to self-treat severe low blood pressure with excessive salt or fluids without clinical guidance, especially if you have heart or kidney conditions.
Store losartan tablets at room temperature (ideally 20–25°C/68–77°F), away from excess heat, moisture, and direct light. Avoid storing in bathrooms. Keep tablets in their original, tightly closed container; if a desiccant packet is present, leave it inside the bottle. Do not use tablets that are discolored, chipped, or past the expiration date.
Keep out of reach of children and pets. If you no longer need the medication, use a medication take-back program when available. If no take-back options exist, follow FDA guidance for safe at-home disposal. Never share prescription medications with others.
In the United States, losartan is a prescription-only medication. Federal and state regulations require that a licensed healthcare professional evaluate whether losartan is appropriate, determine the dose, and monitor safety, particularly kidney function and potassium. It is not lawful to obtain losartan “over the counter” or from unlicensed sources. Any service that provides losartan must operate through proper clinical assessment and pharmacy dispensing channels.
HealthSouth MountainView offers a legal and structured pathway to access losartan by integrating telehealth evaluation, prescribing, and pharmacy fulfillment. After a secure intake, a licensed clinician reviews your medical history, blood pressure readings, and current medications. If losartan is appropriate, the clinician issues an electronic prescription to a U.S.-licensed pharmacy. The medication is dispensed and shipped according to state and federal law. You may not need to handle a paper prescription yourself—your prescription remains on file with the pharmacy—yet the process is fully compliant and clinically supervised.
This model emphasizes patient safety and convenience: identity verification, transparent pricing, medication counseling, and follow-up care are built in. Ongoing blood pressure tracking and lab monitoring can be coordinated to ensure losartan continues to be safe and effective. If losartan is not appropriate, the clinician will recommend alternatives. For urgent symptoms like chest pain, severe shortness of breath, or signs of stroke, call emergency services immediately rather than using telehealth.
Losartan is an angiotensin II receptor blocker (ARB) that lowers blood pressure by blocking AT1 receptors, relaxing blood vessels, reducing aldosterone, and decreasing salt and water retention.
It treats hypertension, slows kidney disease in type 2 diabetes with protein in the urine, and reduces stroke risk in hypertensive patients with left ventricular hypertrophy; it’s also used off-label in heart failure when ACE inhibitors aren’t tolerated.
You may notice improvement within 1 week, with the full effect typically reached in 3–6 weeks.
Commonly 50 mg once daily, adjustable to 25–100 mg per day; some people benefit from splitting the dose to twice daily for better 24‑hour control, especially if blood pressure rises overnight.
Yes, for hypertension in children 6 years and older: about 0.7 mg/kg once daily (up to 50 mg to start), titrated as needed up to 100 mg; pediatric use requires clinician guidance and lab monitoring.
Dizziness, headache, fatigue, low blood pressure, nasal congestion, and gastrointestinal upset; cough is uncommon compared with ACE inhibitors.
High potassium (hyperkalemia), kidney function changes, rare angioedema, and low blood pressure; avoid in bilateral renal artery stenosis and discontinue if pregnancy occurs due to fetal toxicity.
It’s contraindicated during pregnancy (especially in the 2nd and 3rd trimesters) due to serious fetal harm; breastfeeding is not recommended because of limited data—ask about safer alternatives.
Yes: NSAIDs can blunt its effect and worsen kidney function, lithium levels may rise, aliskiren is unsafe with diabetes, and potassium-sparing diuretics, supplements, or salt substitutes raise hyperkalemia risk; food does not significantly affect absorption.
It can increase potassium and creatinine modestly; check blood pressure, potassium, and kidney function 1–2 weeks after starting or changing dose and periodically thereafter.
Losartan uniquely among ARBs lowers uric acid by inhibiting URAT1, which may modestly reduce gout flares, though it’s not a primary gout therapy.
Take it once daily at a consistent time; some patients benefit from bedtime dosing for improved nocturnal control. If the effect wears off early, ask about splitting to twice daily.
Take it when you remember unless it’s close to the next dose; skip the missed dose rather than doubling.
Moderate alcohol may further lower blood pressure and increase dizziness; limit intake and rise slowly from sitting or lying positions.
Blood pressure usually rebounds if you stop; discuss any changes with your clinician and never stop abruptly without a plan.
No significant interaction is known; losartan can be taken with or without grapefruit, though consistent habits are best.
Cough is uncommon with ARBs such as losartan and far less frequent than with ACE inhibitors.
Yes, it’s commonly combined with thiazide diuretics (e.g., hydrochlorothiazide) or calcium channel blockers for stronger blood pressure control.
In patients with high blood pressure and left ventricular hypertrophy, losartan reduced stroke risk versus atenolol; controlling blood pressure overall lowers heart attack, stroke, and heart failure risk.
Check potassium and creatinine about 1–2 weeks after initiation or dose changes, then periodically based on risk factors (e.g., kidney disease, diabetes, age, diuretics).
Both ARBs are effective; valsartan is often slightly stronger at typical doses, while losartan may need higher or twice‑daily dosing in some patients for full 24‑hour coverage.
Candesartan has robust heart failure outcome data and a labeled indication; losartan is used when ACE inhibitors are not tolerated but has less mortality benefit evidence, though high doses (up to 150 mg/day) are used in practice.
Both have strong evidence and indications for type 2 diabetic nephropathy with proteinuria (RENAAL for losartan, IDNT for irbesartan); the choice often comes down to tolerance, cost, and dosing preference.
Telmisartan has a longer half-life (~24 hours) and more consistent 24‑hour blood pressure control; losartan’s active metabolite lasts 6–9 hours, so some patients benefit from twice‑daily dosing.
Olmesartan generally lowers blood pressure more potently once daily; losartan uniquely lowers uric acid. Rarely, olmesartan can cause sprue‑like enteropathy (severe chronic diarrhea and weight loss).
Azilsartan is among the most potent ARBs for blood pressure reduction at equivalent doses; losartan is typically less potent but widely used, inexpensive, and urate‑lowering.
Both are ARBs; eprosartan is used less commonly and may be given twice daily. Losartan has more data in diabetic kidney disease and a uric acid–lowering effect.
Telmisartan, olmesartan, irbesartan, candesartan, and azilsartan provide strong 24‑hour control; losartan and eprosartan sometimes need twice‑daily dosing for trough coverage.
Roughly: losartan 50 mg ≈ valsartan 80 mg ≈ irbesartan 150 mg ≈ candesartan 8 mg ≈ olmesartan 20 mg ≈ telmisartan 40 mg ≈ eprosartan 400 mg ≈ azilsartan 40 mg; maximum daily doses differ by agent.
Class effects are similar: dizziness, hypotension, hyperkalemia, and kidney function changes. Losartan reduces uric acid; olmesartan rarely causes enteropathy; telmisartan’s long action may smooth BP variability.
ARBs (and ACE inhibitors) are often less effective as monotherapy; pairing an ARB with a thiazide diuretic or a calcium channel blocker improves control. Choice among ARBs depends on comorbidities and evidence.
Losartan, valsartan, irbesartan, candesartan, olmesartan, and telmisartan are widely available as generics; losartan is often among the least expensive. Azilsartan can be pricier depending on coverage.
Losartan is unique in lowering uric acid and is preferred if hyperuricemia or gout is a consideration; other ARBs are neutral or can slightly raise uric acid.
Losartan and valsartan have pediatric hypertension labeling; others have limited or no pediatric indications—clinician judgment and guidelines guide selection.
