Isontyn

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

Isontyn is an α1-adrenoceptor antagonist which blocks peripheral postsynaptic receptors resulting to decreased arterial tone. It relaxes smooth muscle of the bladder neck causing a reduction of bladder outlet obstruction.

In general, α1-adrenergic receptors mediate contraction and hypertrophic growth of smooth muscle cells. α1-Receptors are 7-transmembrane domain receptors coupled to G proteins, Gq/11. Three α1-receptor subtypes, which share approximately 75% homology in their transmembrane domains, have been identified: α1A (chromosome 8), α1B (chromosome 5), and α1D (chromosome 20). Isontyn is the first α1-receptor antagonist to demonstrate selectivity for the α1A-receptor. All three receptor subtypes appear to be involved in maintaining vascular tone. The α1A-receptor maintains basal vascular tone while the α1B-receptor mediates the vasocontrictory effects of exogenous α1-agonists. Activation of α1-receptors activates Gq-proteins, which results in intracellular stimulation of phospholipases C, A2, and D. This results in mobilization of Ca2+ from intracellular stores, activation of mitogen-activated kinase and PI3 kinase pathways and subsequent vasoconstriction. Terozosin produces its pharmacological effects by inhibiting α1A-receptor activation. Inhibition of these receptors in the vasculature and prostate results in muscle relaxation, decreased blood pressure and improved urinary outflow in symptomatic benign prostatic hyperplasia.

Isontyn is a quinazoline derivative alpha-1-selective adrenergic blocker.

Trade Name Isontyn
Availability Prescription only
Generic Terazosin
Terazosin Other Names Terazosin, Terazosina, Térazosine, Terazosine, Terazosinum
Related Drugs amlodipine, lisinopril, metoprolol, losartan, furosemide, hydrochlorothiazide, tamsulosin, finasteride, Flomax, prazosin
Type
Formula C19H25N5O4
Weight Average: 387.4329
Monoisotopic: 387.190654313
Protein binding

90-94%.

Groups Approved
Therapeutic Class Alpha adrenoceptor blocking drugs, BPH/ Urinary retention/ Urinary incontinence
Manufacturer
Available Country Argentina
Last Updated: September 19, 2023 at 7:00 am
Isontyn
Isontyn

Uses

Isontyn Hydrochloride single therapy is used to relieve for signs and symptoms of benign prostatic hyperplasia (BPH), for the treatment of hypertension

Isontyn is also used to associated treatment for these conditions: Benign Prostatic Hyperplasia (BPH), High Blood Pressure (Hypertension), Ureteral Calculus

How Isontyn works

Isontyn is selective for alpha-1-adrenoceptors but not their individual subtypes. Inhibition of these alpha-1-adrenoceptors results in relaxation of smooth muscle in blood vessels and the prostate, lowering blood pressure and improving urinary flow. Smooth muscle cells accounts for roughly 40% of the volume of the prostate and so their relaxation reduces pressure on the urethra.

It has also been shown that catecholamines induce factors responsible for mitogenesis and alpha-1-adrenergic receptor blockers inhibit this effect.

A final long term mechanism of terazosin and other alpha-1-adrenergic receptor blockers is the induction of apoptosis of prostate cells. Treatment with terazosin enhances the expression of transforming growth factor beta-1 (TGF-beta1), which upregulates p27kip1, and the caspase cascade.

Dosage

Isontyn dosage

Benign Prostatic Hyperplasia:

  • Initial dose: 1 mg at bedtime is starting dose of all patients and this dose should not be exceeded.
  • Subsequent dose: The dose slowly increases to achieve the desired response. The usual recommended dose range is 5-10 mg administered once a day.

Hypertension:

  • Initial dose: 1 mg at bedtime is starting dose of all patients and this dose should not be exceeded.
  • Subsequent dose: The dose slowly increases to achieve the desired response. The usual recommended dose range is 2-10 mg administered once a day.

Side Effects

Postural hypertension is more commonly reported side effect. Dizziness, lack of energy, peripheral oedema; urinary frequency and priapism reported.

Toxicity

In the event of an overdose, patients may experience hypotension. Blood pressure and heart rate should be controlled by having the patient lie down or by treating with volume expanders or if necessary vasopressors. Patients should be monitored for renal function. Because terazosin is highly protein bound, dialysis is unlikely to provide benefit to overdosing patients.

The oral LD50 in mice is 5500mg/kg.

Precaution

First dose may cause hypotension (within 30-90 minutes). Therefore should be taken on retiring to bed. Caution should be observed when Isontyn is administered with other antihypertensive agents; avoid the possibility of significant hypotension. When adding Isontyn to a diuretic or other antihypertensive agent, dosage reduction and retitration may be necessary. The patients should be cautioned to avoid situation such as driving and hazardous tasks where injury could result due to syncope after initiation of Isontyn therapy.

Interaction

In patients receiving Isontyn plus ACE inhibitors or diuretics the proportion reporting dizziness or related side effects was greater than in the total population of Isontyn treated patients from clinical trials. Isontyn has been given without interaction with analgesics/ anti-inflammatory, cardiac glycosides, hypoglycemic, antiarrhythmic, anxiolytics/ sedatives, antibacterial, hormones/ steroids and drugs used for gout.

Food Interaction

  • Take with or without food. A meal does not significantly affect the extent of absorption but delays Tmax by 40 minutes.

Isontyn Alcohol interaction

[Moderate] GENERALLY AVOID:

The concurrent use of ethanol and alpha-1 adrenergic blockers may cause increased hypotensive effects.

Patients with aldehyde dehydrogenase deficiencies (primarily Asians) may be at a higher risk of this interaction.

The mechanism has not been determined.

Data exist for prazosin and other alpha adrenergic blockers are expected to interact also.

In addition, any patients taking alpha adrenergic blockers may experience excessive orthostatic hypotension with ethanol ingestion, due to ethanol's unopposed vasodilatory effects in the presence of alpha adrenergic blockade.

Patients who develop

a flushing reaction after ethanol ingestion (indicates a possible aldehyde dehydrogenase deficiency) should be advised to avoid ethanol or limit their intake.

All patients should be warned about the possibility of orthostatic hypotension with concurrent ethanol use.

Isontyn Disease Interaction

Moderate: hypotension, liver disease

Volume of Distribution

25L to 30L.

Elimination Route

Approximately 90%.

Half Life

Isontyn has a mean half life 12 hours though this can be as high as 14 hours in patients over 70 years and as low as 11.4 hours in patients 20 to 39 years old.

Clearance

Plasma clearance is 80mL/min and renal clearance is 10mL/min.

Elimination Route

Approximately 10% of the oral dose is excreted unchanged in the urine and approximately 20% is excreted in the feces. 40% of the total dose is eliminated in urine and 60% of the total dose is eliminated in the feces.

Pregnancy & Breastfeeding use

The safety of Isontyn during pregnancy has not been established so Isontyn is not recommended during pregnancy unless the potential benefit justifies the potential risk to moher and fetus. It is not known whether Isontyn is excreted in breast milk. Because many drugs are excreted in breast milk, caution should be exercised when Terazosn is administered to a nursing mother.

Contraindication

Isontyn is contraindicated in patients known to be hypersensitive to Isontyn or its analogues.

Acute Overdose

Acute overdose may lead to acute hypotension, cardiovascular support is of first importance. Restoration of blood pressure and normalization of heart rate may be accomplished by keeping the patient in a supine position. At the same time expansion of plasma volume and nor-adrenergic vasopressor may also be needed.

Storage Condition

Store between 20-25° C. Protect from light and moisture.

Innovators Monograph

You find simplified version here Isontyn

Isontyn contains Terazosin see full prescribing information from innovator Isontyn Monograph, Isontyn MSDS, Isontyn FDA label

FAQ

What is the drug Isontyn used for?

Isontyn is used in men to treat the symptoms of an enlarged prostate , which include difficulty urinating painful urination, and urinary frequency and urgency.

How safe is Isontyn?

Isontyn may cause a sudden drop in your blood pressure, which could lead to dizziness or fainting. This risk is higher when taking your first dose. To avoid injury related to dizziness or fainting, take your first dose of Isontyn at bedtime.

How long should I take Isontyn?

It may take 4 to 6 weeks or longer before you feel the full benefit of Isontyn for BPH. Continue to take Isontyn even if you feel well.

Is it safe to take Isontyn long term?

If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure.

What are the common side effects of Isontyn?

The common side effects of Isontyn are include: 

  • weakness
  • tiredness
  • stuffy or runny nose
  • back pain
  • nausea
  • weight gain
  • decreased sexual ability
  • blurred vision
  • swelling of the hands, feet, ankles, or lower legs
  • pain, burning, numbness, or tingling in the hands or feet

Is Isontyn safe during pregnancy?

This drug should not be used during pregnancy unless the benefit outweighs the risk to the fetus,but potential benefits may warrant use of the drug in pregnant women despite potential risks.

is Isontyn safe during breastfeeding?

Breastfeeding should be avoided during use of this drug.

Can I drink alcohol with Isontyn?

You are advised not to drink alcohol while you are on terazosin. Alcohol increases the risk of side-effects from Isontyn, such as feeling faint or dizzy.

Can I drive after taking Isontyn?

Do not drive a car, operate machinery or perform dangerous tasks for 12 hours after the first time you take Isontyn or after your dose is increased, and until you know how this medication affects you.

Does Isontyn make me sleepy?

Isontyn may cause some people to become drowsy or less alert than they are normally.

How long does it take for Isontyn to lower blood pressure?

Isontyn will start working 15 minutes after taking your dose and will fully kick in within 2 to 3 hours.

Can Isontyn cause kidney damage?

If it continues for a long time, the heart and arteries may not function properly. This can damage .

Should I take Isontyn at night?

Take your first dose of Isontyn at bedtime. Your dose may be gradually increased. You should take your first new dose at bedtime when your dose is increased unless directed otherwise by your doctor.

Does Isontyn treat heart failure?

Brand may have effective applications in the treatment of congestive heart failure.

Can Isontyn cause weight gain?

Patients had a tendency toward a slight weight gain.

Can Isontyn cause shortness of breath?

difficulty breathing,lightheadedness or dizziness upon standing may also occur, especially after the first dose of Isontyn.

How long does Isontyn stay in my system?

Isontyn stay in your system half-life of approximately 12 hours.

What happen If I missed Isontyn?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

How should this medicine be used?

Isontyn comes as a capsule to take by mouth. It is usually taken with or without food once a day at bedtime or twice a day.

What happens if I stop taking Isontyn?

If you stop taking Isontyn or suddenly don't take Isontyn If you're taking this drug to treat BPH, your symptoms may worsen. These symptoms include an urgent need to urinate and a weak urine stream.

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