Co-osar

Co-osar Uses, Dosage, Side Effects, Food Interaction and all others data.

Co-osar, 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. Co-osar and its principal active metabolite block the vasoconstriction and aldosterone secreting effects of angiotensin II to the AT1 receptor found in many tissues. Co-osar is now regarded as the first-line therapy option for treating high blood pressue.

Co-osar is an angiotensin II receptor blocker used to treat hypertension, diabetic nephropathy, and to reduce the risk of stroke. Co-osar 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 Co-osar
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 Lowitt Pharmaceuticals (pvt) Ltd
Available Country Pakistan
Last Updated: September 19, 2023 at 7:00 am
Co-osar
Co-osar

Uses

Co-osar 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.

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

How Co-osar works

Co-osar reversibly and competitively prevents angiotensin II binding to the AT1 receptor in tissues like vascular smooth muscle and the adrenal gland. Co-osar 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. Co-osar'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

Co-osar 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 Co-osar 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 Co-osar. 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 Co-osar. Serious hypotension (particularly on initiating treatment in salt-depleted patients) or renal failure (mainly in patients with renal artery stenosis) may be encountered during Co-osar 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. Co-osar 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

Co-osar is approximately 33% orally bioavailable. Co-osar 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

Co-osar 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 Co-osar in pregnant women, animal studies with Co-osar 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. Co-osar should not be used in pregnancy and if pregnancy is detected Co-osar should be discontinued as soon as possible.

It is not known whether Co-osar is excreted in human breast milk. However, significant level of Co-osar 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 Co-osar potassium should be corrected prior to administer Co-osar 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 Co-osar nor the active metabolite can be removed by hemodialysis.

Storage Condition

Store between 15-30°C

Innovators Monograph

You find simplified version here Co-osar

Co-osar contains Losartan see full prescribing information from innovator Co-osar Monograph, Co-osar MSDS, Co-osar FDA label

FAQ

What is Co-osar used for?

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

How safe is Co-osar?

Co-osar is generally safe to take for a long time. In fact, Co-osar works best when you take it for a long time. Taking Co-osar 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 Co-osar work?

Co-osar 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 Co-osar?

Common side effects of Co-osar 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 Co-osar safe during pregnancy?

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

Is Co-osar safe during breastfeeding?

Co-osar is not known if Co-osar 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 Co-osar?

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

Can I drive after taking Co-osar?

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

When should be taken of Co-osar?

Take Co-osar 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 Co-osar at any time of day. Try to take it at the same time every day.

Can I take Co-osar on an empty stomach?

You can take Co-osar tablets with or without food. Swallow the tablets with a drink of water.

Is it better to take Co-osar 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 Co-osar take to work?

Co-osar 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 Co-osar stay in my system?

The Co-osar 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 Co-osar and its metabolite from your system.

Can I take Co-osar for a long time?

Co-osar  is generally safe to take for a long time. In fact, it works best when you take it for a long time. However taking Co-osar 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 Co-osar bad for my kidney?

There is a risk of acute kidney failure developing in people taking Co-osar.

Can I take Co-osar 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 Co-osar tablets with or without food.

How many hours does Co-osar last?

Co-osar taken once daily, does not last the full 24 hours at lower doses like 25 or 50 mg. At 100 mg daily Co-osar does last the full 24 hours. If you take Co-osar 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 Co-osar?

An overdose of Co-osar can cause dizziness, sleepiness and a pounding heartbeat.

What happen If I stop taking Co-osar?

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 Co-osar, talk with your doctor. They will slowly taper your dosage so that you can stop using the drug safely.

Can Co-osar cause heart problems?

An irregular heartbeat  has been reported with Co-osar but is rare.

Can Co-osar affects my liver?

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

Will Co-osar 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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