Losartan Pharmaclan

What Is Losartan Pharmaclan and What Is It Used For?

Losartan Pharmaclan contains the active substance losartan potassium, which belongs to a group of medicines called angiotensin II receptor blockers (ARBs). It is prescribed to treat high blood pressure, protect the kidneys in patients with type 2 diabetes who have proteinuria, and reduce the risk of stroke in hypertensive patients with left ventricular hypertrophy.

Losartan works by selectively blocking the angiotensin II type 1 (AT1) receptor. Angiotensin II is a powerful hormone in the body that causes blood vessels to constrict and stimulates the release of aldosterone from the adrenal glands, which in turn causes the kidneys to retain sodium and water. By blocking the AT1 receptor, losartan prevents these effects, leading to vasodilation (widening of blood vessels), reduced aldosterone secretion, and ultimately a decrease in blood pressure.

In the treatment of high blood pressure (hypertension), losartan reduces the resistance in blood vessels, allowing blood to flow through more easily. This lowers both systolic and diastolic blood pressure, reducing the workload on the heart and protecting against the long-term complications of uncontrolled hypertension, including heart attack, stroke, heart failure, and kidney disease. The European Society of Cardiology (ESC) and the American Heart Association (AHA) both recommend ARBs, including losartan, as first-line treatment options for hypertension.

Losartan also plays an important role in diabetic nephropathy (kidney disease caused by type 2 diabetes). In patients with type 2 diabetes who have high blood pressure and evidence of protein in the urine (proteinuria), losartan has been shown to slow the progression of kidney disease and reduce the risk of end-stage renal disease requiring dialysis. The landmark RENAAL (Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan) trial demonstrated that losartan reduced the risk of doubling of serum creatinine by 25% and end-stage renal disease by 28% compared to placebo, on top of conventional antihypertensive therapy.

Additionally, losartan is indicated for stroke risk reduction in patients with hypertension and electrocardiographic evidence of left ventricular hypertrophy (thickening of the heart muscle). The LIFE (Losartan Intervention For Endpoint reduction in hypertension) study showed that losartan-based treatment reduced the risk of stroke by 25% compared to atenolol-based treatment, despite similar blood pressure reductions. This suggests that losartan has protective effects beyond simple blood pressure lowering.

An additional and unique pharmacological property of losartan among the ARBs is its uricosuric effect – it promotes the excretion of uric acid through the kidneys. This can lead to a modest reduction in serum uric acid levels, which may be clinically beneficial in patients who also have gout or hyperuricaemia. This effect is specific to losartan and is not shared by other ARBs such as valsartan, candesartan, or irbesartan.

What Should You Know Before Taking Losartan Pharmaclan?

Before starting losartan, inform your doctor about all medical conditions, particularly kidney disease, liver disease, dehydration, heart failure, and whether you are pregnant or planning to become pregnant. Losartan is strictly contraindicated in pregnancy and must not be combined with aliskiren in patients with diabetes or renal impairment.

Contraindications

You should not take Losartan Pharmaclan if any of the following apply to you:

• Allergy to losartan or any of the other ingredients in the tablet – symptoms of an allergic reaction may include rash, itching, swelling of the face, lips, tongue or throat, or difficulty breathing
• Pregnancy (second and third trimester) – losartan can cause serious harm to the developing foetus, including kidney failure, reduced amniotic fluid, skull bone malformations, and death. Use in the first trimester is also not recommended
• Severe liver disease – losartan is extensively metabolised in the liver, and impaired hepatic function can lead to significantly increased drug exposure
• Concomitant use with aliskiren in patients with diabetes mellitus or renal impairment (GFR <60 mL/min/1.73 m²) – dual blockade of the renin-angiotensin-aldosterone system increases the risk of hyperkalaemia, hypotension, and renal failure
• Breastfeeding – it is not known whether losartan passes into breast milk; due to potential adverse effects on the nursing infant, losartan should not be used while breastfeeding

Warnings and Precautions

Talk to your doctor or pharmacist before taking Losartan Pharmaclan if you have or have had any of the following conditions:

• Kidney disease – your doctor will need to monitor your kidney function and potassium levels regularly, and may need to adjust the dose. If you have renal artery stenosis (narrowing of the blood vessels leading to one or both kidneys), losartan may cause a deterioration in kidney function
• Liver disease – losartan undergoes extensive first-pass metabolism in the liver. Patients with mild to moderate liver impairment have approximately doubled plasma concentrations of losartan and its active metabolite. A lower starting dose may be necessary
• Dehydration or salt depletion – if you have recently experienced severe vomiting or diarrhoea, or are taking high-dose diuretics, you may have reduced blood volume and be at increased risk of symptomatic hypotension (sudden drop in blood pressure causing dizziness or fainting) when starting losartan
• Heart failure – there is a risk of impaired kidney function and severe hypotension, particularly in patients with severe heart failure. Close monitoring is required
• Electrolyte disturbances – losartan can increase potassium levels in the blood (hyperkalaemia), particularly in patients with impaired kidney function, diabetes, or those taking other medications that raise potassium
• Aortic or mitral valve stenosis – use with caution in patients with obstruction to outflow from the left ventricle
• Primary aldosteronism – patients with primary aldosteronism generally do not respond well to antihypertensive medicines that work through the renin-angiotensin-aldosterone system

Pregnancy and Breastfeeding

Losartan is strictly contraindicated during pregnancy. All medicines that act directly on the renin-angiotensin-aldosterone system (RAAS) – including ARBs like losartan and ACE inhibitors – have been associated with serious foetal and neonatal toxicity when used during the second and third trimesters. These adverse effects include renal failure, oligohydramnios, hypoplasia of the skull bones, hypotension, and death. Even first-trimester exposure is not recommended based on epidemiological data suggesting potential risk, although the evidence is less conclusive.

If you discover you are pregnant while taking losartan, the medication must be discontinued immediately and an alternative antihypertensive prescribed. Your doctor may recommend labetalol, methyldopa, or nifedipine (extended-release) as safer alternatives during pregnancy. Regular ultrasound monitoring of the foetus should be performed if there has been any exposure to losartan during pregnancy.

It is not known whether losartan or its active metabolite is excreted in human breast milk. Because of the potential for serious adverse effects in nursing infants, losartan should not be used during breastfeeding. If treatment with an ARB is considered essential, breastfeeding should be discontinued.

Driving and Operating Machinery

When starting losartan treatment or when the dose is increased, some patients may experience dizziness or light-headedness, particularly when standing up quickly (orthostatic hypotension). If you experience these symptoms, you should not drive or operate machinery until they have resolved. However, most patients tolerate losartan well, and these effects are generally transient and mild. If symptoms persist, consult your doctor.

How Does Losartan Pharmaclan Interact with Other Drugs?

Losartan can interact with potassium supplements, potassium-sparing diuretics, lithium, NSAIDs, other RAAS inhibitors (ACE inhibitors, aliskiren), and CYP2C9 inhibitors such as fluconazole. Always inform your doctor about all medications, supplements, and herbal products you are taking.

Losartan is metabolised primarily by the liver enzyme CYP2C9 (and to a lesser extent CYP3A4) to its active carboxylic acid metabolite E-3174, which is responsible for most of the antihypertensive effect. Drugs that inhibit CYP2C9 can reduce the conversion of losartan to its active metabolite, potentially reducing its efficacy. Conversely, CYP2C9 enzyme inducers can increase the formation of the active metabolite. Understanding these interactions is essential for safe and effective use of losartan.

Major Interactions

Moderate Interactions

What Is the Correct Dosage of Losartan Pharmaclan?

The usual starting dose for adults with hypertension is 50 mg once daily, which may be increased to 100 mg once daily for optimal blood pressure control. For diabetic nephropathy, the target dose is 100 mg once daily. Dosage may need to be reduced in patients with liver impairment or those on haemodialysis.

Adults

The dosing of losartan varies depending on the indication and individual patient factors. The following table summarises the standard dosing recommendations based on international guidelines and the product's prescribing information.

Losartan can be taken with or without food, at any time of day, but should be taken at the same time each day for consistent effect. The tablets should be swallowed whole with a glass of water. The full antihypertensive effect typically develops within 3 to 6 weeks of starting treatment, although some blood pressure lowering is observed within the first week.

Children and Adolescents

Losartan may be used for the treatment of hypertension in children and adolescents aged 6 to 18 years. The starting dose depends on body weight:

• Children weighing 20 to 50 kg: 0.7 mg/kg once daily (approximately 25 mg), up to a maximum of 50 mg once daily
• Children weighing more than 50 kg: 50 mg once daily, up to a maximum of 100 mg once daily

Losartan is not recommended for children under 6 years of age due to lack of sufficient clinical data. In children with reduced kidney function (GFR <30 mL/min/1.73 m²), losartan is not recommended as there is insufficient experience. Your child's doctor will determine the appropriate dose based on weight, blood pressure response, and kidney function.

Elderly Patients

No initial dose adjustment is generally required in elderly patients. However, elderly patients may be more susceptible to the blood pressure-lowering effects of losartan, particularly if they are volume-depleted due to diuretic therapy or reduced fluid intake. Close monitoring is recommended when starting treatment, and the dose should be increased gradually based on individual response and tolerability.

Missed Dose

If you forget to take a dose, take it as soon as you remember, provided it is not close to the time of your next scheduled dose. If it is nearly time for your next dose, skip the missed dose and take the next one at the regular time. Do not take a double dose to make up for a forgotten dose. If you frequently forget doses, consider setting a daily reminder or associating the medication with a routine activity such as breakfast.

Overdose

In the event of an overdose, the most likely symptoms are low blood pressure (hypotension) and rapid heart rate (tachycardia). Bradycardia (slow heart rate) could also occur due to parasympathetic stimulation. If severe hypotension occurs, the patient should be placed in a supine position with legs elevated and given intravenous normal saline. Losartan is not removed by haemodialysis. If you suspect an overdose, seek immediate medical attention or contact your local poison control centre.

What Are the Side Effects of Losartan Pharmaclan?

Like all medicines, losartan can cause side effects, although not everybody gets them. The most common side effects include dizziness, hyperkalaemia (elevated potassium), and fatigue. Losartan is generally well tolerated and notably causes less dry cough compared to ACE inhibitors.

The following side effect frequency grid is based on data from clinical trials and post-marketing surveillance. Side effects are classified by frequency according to the standard MedDRA convention. If you experience any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed below. You can also report side effects directly to your national medicines regulatory authority.

One of the key clinical advantages of losartan and other ARBs over ACE inhibitors is the significantly lower incidence of dry cough. The persistent, tickly cough associated with ACE inhibitors (which occurs in up to 10–15% of patients and is a common reason for discontinuation) is caused by the accumulation of bradykinin. Because losartan does not inhibit ACE and does not cause bradykinin accumulation, the cough rate is comparable to placebo in clinical trials. This makes losartan a preferred alternative for patients who have experienced ACE inhibitor-related cough.

If any of the side effects listed above become severe, or if you notice any side effects not listed here, please tell your doctor or pharmacist. Reporting side effects helps to provide more information on the safety of this medicine.

How Should You Store Losartan Pharmaclan?

Store Losartan Pharmaclan below 30°C in the original packaging to protect it from moisture and light. Keep all medicines out of the sight and reach of children. Do not use after the expiry date stated on the packaging.

Proper storage of your medication is essential to ensure it remains effective and safe throughout its shelf life. Follow these storage guidelines:

• Temperature: Store below 30°C (86°F). Do not refrigerate or freeze the tablets
• Moisture protection: Keep the tablets in the original blister pack or container until ready to use. Do not transfer to another container unless it provides equivalent moisture protection
• Light protection: Store in the original packaging to protect from light
• Keep out of reach of children: Store all medicines in a secure location where children cannot access them
• Expiry date: Do not use Losartan Pharmaclan after the expiry date printed on the carton and blister (EXP). The expiry date refers to the last day of that month

Do not dispose of medicines in household waste or via wastewater. Ask your pharmacist about how to dispose of medicines you no longer use. Proper disposal helps protect the environment and prevents accidental ingestion by children or pets.

What Does Losartan Pharmaclan Contain?

Each film-coated tablet contains 50 mg of losartan potassium as the active ingredient. The tablets also contain various inactive ingredients (excipients) that help form the tablet and its film coating.

The active substance is losartan potassium. Each film-coated tablet contains 50 mg of losartan potassium, equivalent to approximately 45.8 mg of losartan free acid. Losartan potassium is a white to off-white crystalline powder that is freely soluble in water.

The inactive ingredients (excipients) typically include:

• Tablet core: Microcrystalline cellulose, lactose monohydrate, pregelatinised maize starch, magnesium stearate, hydroxypropylcellulose, hypromellose
• Film coating: Hypromellose, titanium dioxide (E171), talc, propylene glycol. Some strengths may also contain iron oxide yellow (E172) as a colouring agent

If you have any known allergies or intolerances to any of these ingredients (for example, lactose intolerance), inform your doctor or pharmacist before starting treatment. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency, or glucose-galactose malabsorption should not take this medicine due to the lactose content.

How Does Losartan Pharmaclan Work in the Body?

Losartan blocks the angiotensin II type 1 (AT1) receptor, preventing angiotensin II from constricting blood vessels and stimulating aldosterone release. This leads to vasodilation, reduced sodium and water retention, and lower blood pressure. Its active metabolite E-3174 is responsible for most of the sustained antihypertensive effect.

To understand how losartan works, it is helpful to understand the renin-angiotensin-aldosterone system (RAAS), one of the body's most important blood pressure regulation systems. When blood pressure falls or blood flow to the kidneys decreases, the kidneys release an enzyme called renin. Renin converts angiotensinogen (a protein produced by the liver) into angiotensin I, which is then converted by angiotensin-converting enzyme (ACE) into angiotensin II – a potent vasoconstrictor.

Angiotensin II exerts its effects by binding to two main receptor subtypes: AT1 and AT2. The AT1 receptor mediates virtually all the known cardiovascular effects of angiotensin II, including vasoconstriction, aldosterone secretion, sympathetic nervous system activation, cardiac hypertrophy, and vascular smooth muscle proliferation. The AT2 receptor appears to have counter-regulatory, protective effects including vasodilation, anti-proliferation, and anti-inflammatory actions.

Losartan selectively blocks the AT1 receptor while leaving the AT2 receptor unblocked. This means that not only are the harmful effects of angiotensin II at the AT1 receptor prevented, but the unblocked AT2 receptor may continue to provide protective effects. This selective mechanism is one of the theoretical advantages of ARBs over ACE inhibitors, which reduce the overall production of angiotensin II and therefore reduce signalling at both receptor subtypes.

Another important pharmacological distinction is that ACE inhibitors also inhibit the breakdown of bradykinin, a substance that promotes vasodilation but also causes cough. Because losartan does not affect ACE activity or bradykinin metabolism, it produces vasodilation without the cough-inducing side effect. This is the primary reason why losartan is much better tolerated than ACE inhibitors with respect to respiratory side effects.

After oral administration, losartan is well absorbed and undergoes extensive first-pass metabolism in the liver, primarily by CYP2C9 and CYP3A4, to form its active metabolite E-3174. This metabolite is 10 to 40 times more potent as an AT1 receptor antagonist and has a longer duration of action (half-life 6–9 hours) compared to the parent compound (half-life approximately 2 hours). The bioavailability of losartan is approximately 33%, meaning about one-third of the orally administered dose reaches the systemic circulation. Both losartan and E-3174 are highly bound to plasma proteins (over 98%) and are eliminated primarily through the bile and, to a lesser extent, the urine.

Frequently Asked Questions