Losartin

Losartin Uses, Dosage, Side Effects, Food Interaction and all others data.

Losartin, the first of a new class of antihypertensives, is a specific and selective antagonist of angiotensin II at the AT1 sites. Angitensin II is a potent vasoconstrictor, the primary vasoactive hormone of the renin-angiotensin system and an important component in the pathophysiology of hypertension. Losartin and its principal active metabolite block the vasoconstriction and aldosterone secreting effects of angiotensin II to the AT1 receptor found in many tissues. Losartin is now regarded as the first-line therapy option for treating high blood pressue.

Losartin is an angiotensin II receptor blocker used to treat hypertension, diabetic nephropathy, and to reduce the risk of stroke. Losartin has a long duration of action as it is given once daily. Patients taking losartan should be regularly monitored for hypotension, renal function, and potassium levels.

Trade Name Losartin
Availability Prescription only
Generic Losartan
Losartan Other Names Losartan
Related Drugs amlodipine, lisinopril, metoprolol, furosemide, hydrochlorothiazide, atenolol, ramipril, captopril, enalapril, irbesartan
Weight 50mg
Type Tablet
Formula C22H23ClN6O
Weight Average: 422.911
Monoisotopic: 422.162187095
Protein binding

Losartan is 98.6-98.8% protein bound and the active metabolite (E-3174) is 99.7% protein bound in serum.

Groups Approved
Therapeutic Class Angiotensin-ll receptor blocker
Manufacturer Tagma Pharma (pvt) Ltd,
Available Country Pakistan
Last Updated: September 19, 2023 at 7:00 am
Losartin
Losartin

Uses

Losartin is an angiotensin II receptor blocker (ARB) used for:

  • Treatment of hypertension, to lower blood pressure in adults and children greater than 6 years old. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions.
  • Reduction of the risk of stroke in patients with hypertension and left ventricular hypertrophy. There is evidence that this benefit does not apply to Black patients.
  • Treatment of diabetic nephropathy with an elevated serum creatinine and proteinuria in patients with type 2 diabetes and a history of hypertension.

Losartin is also used to associated treatment for these conditions: Diabetic Nephropathy, Heart Failure, High Blood Pressure (Hypertension), Marfan Syndrome, Stroke

How Losartin works

Losartin reversibly and competitively prevents angiotensin II binding to the AT1 receptor in tissues like vascular smooth muscle and the adrenal gland. Losartin and its active metabolite bind the AT1 receptor with 1000 times more affinity than they bind to the AT2 receptor. The active metabolite of losartan is 10-40 times more potent by weight than unmetabolized losartan as an inhibitor of AT1 and is a non-competitive inhibitor. Losartin's prevention of angiotensin II binding causes vascular smooth muscle relaxation, lowering blood pressure.

Angiotensin II would otherwise bind to the AT1 receptor and induce vasoconstriction, raising blood pressure.

Dosage

Losartin dosage

Hypertension:

  • Usual adult dose: 50 mg once daily.
  • Usual pediatric starting dose: 0.7 mg per kg once daily (up to 50 mg).

Hypertensive Patients with Left Ventricular Hypertrophy:

  • Usual starting dose: 50 mg once daily.
  • Add hydrochlorothiazide 12.5 mg and/or increase Losartin to 100 mg followed by an increase to hydrochlorothiazide 25 mg if further blood pressure response is needed.

Nephropathy in Type 2 Diabetic Patients:

  • Usual dose: 50 mg once daily.
  • Increase dose to 100 mg once daily if further blood pressure response is needed.

Use in elderly:

  • Patients up to 75 years: No initial dosage adjustment is necessary for this group of patients.
  • Patients over 75 years: A lower starting dose of 25 mg once daily is recommended.

Side Effects

In controlled clinical trials in patients with essential hypertension, dizziness was the only side effect reported that occurred with an incidence greater than placebo in 1% or more of patients treated with Losartin. Rarely, rash was reported although the incidence in controlled clinical trials was less than placebo. Angioedema, involving swelling of the face, lips and/or tongue has been reported rarely in patients treated with Losartin. Serious hypotension (particularly on initiating treatment in salt-depleted patients) or renal failure (mainly in patients with renal artery stenosis) may be encountered during Losartin treatment.

Toxicity

The oral TDLO in mice is 1000mg/kg and in rats is 2000mg/kg. In humans the TDLO for men is 10mg/kg/2W and for women is 1mg/kg/1D.

Symptoms of overdose are likely to include hypotension, tachycardia, or bradycardia due to vagal stimulation. Supportive treatment should be instituted for symptomatic hypotension. Hemodialysis will not remove losartan or its active metabolite due to their high rates of protein binding.

Precaution

A lower dose should be considered for patients with a history of hepatic and renal impairment. Losartin should not be used with potassium-sparing diuretic

Interaction

No drug interaction of clinical significance has been identified. Compounds which have been studied in clinical pharmacokinetic trials include hydrochlorothiazide, digoxin, warfarin, cimetidine, ketoconazole and phenobarbital.

Food Interaction

  • Take at the same time every day.
  • Take with or without food. Food delays absorption, but does not affect the extent of absorption.

[Moderate] GENERALLY AVOID: Moderate-to-high dietary intake of potassium, especially salt substitutes, may increase the risk of hyperkalemia in some patients who are using angiotensin II receptor blockers (ARBs).

ARBs can promote hyperkalemia through inhibition of angiotensin II-induced aldosterone secretion.

Patients with diabetes, heart failure, dehydration, or renal insufficiency have a greater risk of developing hyperkalemia.

MANAGEMENT: Patients should receive dietary counseling and be advised to not use potassium-containing salt substitutes or over-the-counter potassium supplements without consulting their physician.

If salt substitutes are used concurrently, regular monitoring of serum potassium levels is recommended.

Patients should also be advised to seek medical attention if they experience symptoms of hyperkalemia such as weakness, irregular heartbeat, confusion, tingling of the extremities, or feelings of heaviness in the legs.

MONITOR: Grapefruit juice may modestly decrease and delay the conversion of losartan to its active metabolite, E3174.

The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits.

The clinical significance is unknown.

Moreover, pharmacokinetic alterations associated with interactions involving grapefruit juice are often subject to a high degree of interpatient variability.



MANAGEMENT: Patients who regularly consume grapefruits and grapefruit juice should be monitored for altered efficacy of losartan.

Grapefruits and grapefruit juice should be avoided if an interaction is suspected.

Orange juice is not expected to interact.

Volume of Distribution

The volume of distribution of losartan is 34.4±17.9L and 10.3±1.1L for the active metabolite (E-3174).

Elimination Route

Losartin is approximately 33% orally bioavailable. Losartin has a Tmax of 1 hour and the active metabolite has a Tmax of 3-4 hours. Taking losartan with food decreases the Cmax but does only results in a 10% decrease in the AUC of losartan and its active metabolite. A 50-80mg oral dose of losartan leads to a Cmax of 200-250ng/mL.

Half Life

The terminal elimination half life of losartan is 1.5-2.5 hours while the active metabolite has a half life of 6-9 hours.

Clearance

Losartin has a total plasma clearance of 600mL/min and a renal clearance of 75mL/min. E-3174, the active metabolite, has a total plasma clearance of 50mL/min and a renal clearance of 25mL/min.

Elimination Route

A single oral dose of losartan leads to 4% recovery in the urine as unchanged losartan, 6% in the urine as the active metabolite. Oral radiolabelled losartan is 35% recovered in urine and 60% in feces. Intravenous radiolabelled losartan is 45% recovered in urine and 50% in feces.

Pregnancy & Breastfeeding use

Although there is no experience with the use of Losartin in pregnant women, animal studies with Losartin potassium have demonstrated fetal and neonatal injury and death, the mechanism of which is believed to be pharmacologically mediated through effects on the renin angiotensinaldosterone system. Losartin should not be used in pregnancy and if pregnancy is detected Losartin should be discontinued as soon as possible.

It is not known whether Losartin is excreted in human breast milk. However, significant level of Losartin found in rat milk which suggests that the drug should not be used in lactating mother.

Contraindication

It is also contraindicated to patients who are hypersensitive to any component of this product. In patients who are intravenously volume depleted (e.g. those treated with high dose diuretics), symptomatic hypotension may occur. These conditions Losartin potassium should be corrected prior to administer Losartin or a lower starting dose (usually 25 mg) should be used.

Special Warning

No initial dosage adjustment is necessary in patients with mild renal impairment (CrCl 20-50 ml/min). For patients with moderate to severe renal impairment (CrCl <20 ml/min) or patients on dialysis, a lower starting dose of 25 mg is recommended.

Acute Overdose

Limited data are available regarding overdose in humans. The most likely manifestation of overdose would be hypotension and tachycardia; bradycardia could occur from parasympathetic (vagal) stimulation. Supportive treatment should include repletion of the intravascular volume. Neither Losartin nor the active metabolite can be removed by hemodialysis.

Storage Condition

Store between 15-30°C

Innovators Monograph

You find simplified version here Losartin

Losartin contains Losartan see full prescribing information from innovator Losartin Monograph, Losartin MSDS, Losartin FDA label

FAQ

What is Losartin used for?

Losartin used to treat high blood pressure. It is also used for diabetic kidney disease, heart failure, and left ventricular enlargement. Losartin protect your kidneys if you have both kidney disease and diabetes.

How safe is Losartin?

Losartin is generally safe to take for a long time. In fact, Losartin works best when you take it for a long time. Taking Losartin for a long time can sometimes cause your kidneys not to work as well as they should. Your doctor will check how well your kidneys are working with regular blood tests.

How does Losartin work?

Losartin relaxes and widens your blood vessels. This lowers your blood pressure and makes it easier for your heart to pump blood around your body.

What are the common side effects of Losartin?

Common side effects of Losartin are include:

  • Blurred vision.
  • difficult breathing.
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position.
  • fast or irregular heartbeat.
  • nausea or vomiting.
  • numbness or tingling in the hands, feet, or lips.
  • stomach pain.
  • weakness or heaviness of the legs.

Is Losartin safe during pregnancy?

Do not take Losartin if you are pregnant. If you become pregnant while you are taking Losartin, stop taking Losartin and call your doctor immediately. Losartin may cause death or serious injury to the fetus when taken in the last 6 months of pregnancy.

Is Losartin safe during breastfeeding?

Losartin is not known if Losartin passes into breast milk. It is not recommended for women who are breastfeeding because other medicines with a more established safety profile are available.

Can I drink alcohol with Losartin?

Losartin may cause low blood pressure, resulting in dizziness, lightheadedness, and fainting. Moderate alcohol consumption while taking Losartin is generally considered safe, but alcohol may make the side effects of Losartin worse.

Can I drive after taking Losartin?

Avoid driving or using heavy machinery while dizzy. See a doctor if dizziness or lightheadedness persists or gets worse.

When should be taken of Losartin?

Take Losartin tablets once a day. Your doctor may suggest that you take your first dose before bedtime, because it can make you dizzy. After the very first dose, you can take Losartin at any time of day. Try to take it at the same time every day.

Can I take Losartin on an empty stomach?

You can take Losartin tablets with or without food. Swallow the tablets with a drink of water.

Is it better to take Losartin in the morning or in the evening?

For once daily dosing, there are no absolute recommendations about taking it in the morning vs. night. For high blood pressure, some research suggests taking medicines at night reduces the risk of cardiovascular events in the morning.

How long does Losartin take to work?

Losartin starts to reduce high blood pressure after about 6 hours but it may take 3 to 6 weeks to fully take effect. If you have high blood pressure, you may not have any symptoms.

How long does Losartin stay in my system?

The Losartin half-life is about 2 hours and the metabolite half-life is 6 to 9 hours. This means it can take a couple of days to clear Losartin and its metabolite from your system.

Can I take Losartin for a long time?

Losartin  is generally safe to take for a long time. In fact, it works best when you take it for a long time. However taking Losartin for a long time can sometimes cause your kidneys not to work as well as they should. Your doctor will check how well your kidneys are working with regular blood tests.

Is Losartin bad for my kidney?

There is a risk of acute kidney failure developing in people taking Losartin.

Can I take Losartin every other day?

Your doctor may suggest that you take your first dose before bedtime, because it can make you dizzy. After the very first dose, you can take losartan at any time of day. Try to take it at the same time every day. You can take Losartin tablets with or without food.

How many hours does Losartin last?

Losartin taken once daily, does not last the full 24 hours at lower doses like 25 or 50 mg. At 100 mg daily Losartin does last the full 24 hours. If you take Losartin 50 mg in the morning, you may notice your blood pressure rises at night, because it's not covering you for a full 24 hours.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happen If I overdose on Losartin?

An overdose of Losartin can cause dizziness, sleepiness and a pounding heartbeat.

What happen If I stop taking Losartin?

Stopping it suddenly can cause your blood pressure to increase quickly. This raises your risk of a heart attack or stroke. If you want to stop taking Losartin, talk with your doctor. They will slowly taper your dosage so that you can stop using the drug safely.

Can Losartin cause heart problems?

An irregular heartbeat  has been reported with Losartin but is rare.

Can Losartin affects my liver?

Losartin is associated with a low rate of transient serum aminotransferase elevations and has been linked to rare instances of acute liver injury.

Will Losartin affect my fertility?

One experimental animal study did not find effects on fertility.

*** Taking medicines without doctor's advice can cause long-term problems.
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