Irbesartan-Hydrochlorothiazide (irbesartan/hydrochlorothiazide)
Last reviewed · Source: First Databank (FDB) drug data
Overview
Hydrochlorothiazide is a thiazide diuretic and antihypertensive agent.
Irbesartan, a nonpeptide tetrazole derivative, is an angiotensin II type 1 (AT1) receptor antagonist (also referred to as an angiotensin II receptor blocker (ARB)).
Irbesartan, a nonpeptide tetrazole derivative, is a specific competitive inhibitor of the angiotensin II receptor (type AT1) with a much greater affinity for the AT1 receptor than the AT2 receptor and no agonist activity. Through selective blockade of angiotensin II binding at the AT1 receptor, irbesartan blocks the physiologic actions of angiotensin II, including vasoconstrictor and aldosterone-secreting effects. Irbesartan does not inhibit angiotensin converting enzyme (ACE) or renin, and does not bind to or block other hormone receptors or ion channels known to be important in cardiovascular regulation.
A dose of irbesartan 150-300 mg inhibits angiotensin II pressor effects by 100% at 4 hours post-dose, with 40-60% inhibition persisting for 24 hours.
Irbesartan is rapidly and completely absorbed following oral administration, with a bioavailability between 60-80%. Peak plasma concentrations generally occur at 1.5-2 hours following administration. Administration with a meal does not affect bioavailability.
The pharmacokinetics of irbesartan are linear over its therapeutic dose range. Irbesartan is 90% protein bound, primarily to albumin and alpha1-acid glycoprotein. Distribution across the blood-brain barrier is weak.
Following oral or IV administration, >80% of the circulating plasma radioactivity is attributable to unchanged irbesartan, with approximately 6% attributable to an inactive glucuronide conjugate metabolite. In vitro studies indicate that cytochrome P-450 (CYP)2C9 is primarily involved in the metabolism of irbesartan, with negligible metabolism by CYP3A4. The terminal half-life of irbesartan is 11-15 hours.
After a single oral or IV dose, about 20% of radioactivity appears in urine; the remainder appears in the feces as irbesartan or its inactive metabolite. Elimination occurs via biliary and renal excretion. In studies of irbesartan in hypertensive patients, no differences in half-life or accumulation were observed based on sex; however, female patients had 11-44% higher plasma concentrations than males.
Irbesartan AUC values are approximately 25% higher in Black patients compared to White patients; however, there is no difference between these groups in peak plasma concentrations.
USES: This medication is used to treat high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. This product contains 2 medications, irbesartan and hydrochlorothiazide.
Irbesartan belongs to a class of drugs known as angiotensin receptor blockers (ARBs). It works by relaxing blood vessels so blood can flow more easily. Hydrochlorothiazide is a "water pill" (diuretic) that causes you to make more urine.
This helps your body get rid of extra water and salt.
Generic name: irbesartan/hydrochlorothiazide
Pronunciation: (ir-be-SAR-tan/HYE-droe-KLOR-oh-THYE-a-zide)
Reference product & biosimilars
No reference, biosimilar or interchangeable associated with this drug.
Today’s intelligence on Irbesartan-Hydrochlorothiazide
Indications
The following indications are listed for Irbesartan-Hydrochlorothiazide:
- Hypertension
Also known as: Elevated Blood Pressure, Essential Hypertension, Hyperpiesia, Hyperpiesis, Hypertensive Disorder, Systemic Arterial Hypertension.
Dosing
Dosage of hydrochlorothiazide should be individualized according to the patient's requirements and response. The lowest dosage necessary to produce the desired clinical effect should be used. If hydrochlorothiazide is added to the regimen of a patient stabilized on a potent hypotensive agent, dosage of the hypotensive agent should initially be reduced to avoid the possibility of severe hypotension.
Hydrochlorothiazide is administered orally.
Irbesartan is administered orally as tablets. Irbesartan is also commercially available as a fixed-combination tablet containing irbesartan and hydrochlorothiazide; see the full prescribing information for administration of this combination product.
Since food does not affect the oral bioavailability of irbesartan, the manufacturer states that the drug can be taken without regard to meals.
Irbesartan tablets should be stored at 25degreesC (excursions permitted between 15-30degreesC).
No dosing information is available for this tab.
No dosing information is available for this tab.
Drug interactions
Irbesartan is metabolized principally by cytochrome P-450 (CYP) 2C9 isoenzyme. The drug does not substantially induce or inhibit CYP1A1, 1A2, 2A6, 2B6, 2D6, 2E1, or 3A4.
There are no contraindication interactions for this drug.
There are no severe interactions for this drug.
There are no moderate interactions for this drug.
Contraindications
*Known hypersensitivity to irbesartan or any ingredient in the formulation.
*Concomitant use with aliskiren in patients with diabetes mellitus.
There are no contraindication contraindications for this drug.
There are no severe contraindications for this drug.
There are no moderate contraindications for this drug.
Adverse reactions
The most common adverse effects occurring in patients receiving irbesartan for the treatment of diabetic nephropathy include hyperkalemia, dizziness, orthostatic dizziness, and orthostatic hypotension. Intestinal angioedema has also been reported.
There are no severe adverse reactions for this drug.
There are no less severe adverse reactions for this drug.
Precautions
No enhanced messaging available.
Administration of irbesartan in dosages of up to 4.5 mg/kg once daily did not appear to effectively lower blood pressure in pediatric patients 6-16 years of age.
Safety and efficacy of irbesartan in children <6 years of age have not been established.
If oliguria or hypotension occurs in neonates with a history of in utero exposure to irbesartan, blood pressure and renal function should be supported; exchange transfusions or dialysis may be required.
Irbesartan can cause fetal harm when administered to a pregnant woman. (See Fetal/Neonatal Morbidity and Mortality under Cautions).
Discontinue irbesartan as soon as possible when pregnancy is detected. In the rare case that there is no appropriate alternative therapy, apprise the mother of the potential risk to the fetus. If irbesartan is used during pregnancy, perform serial ultrasound examinations to assess the intra-amniotic environment; if oligohydramnios is observed, consider alternative treatment. Oligohydramnios may not appear until after the fetus has sustained irreversible injury. Closely observe neonates who have been exposed to irbesartan in utero for signs of hypotension, oliguria, hyperkalemia, and other signs of renal impairment. If oliguria or hypotension occurs, support blood pressure and renal perfusion. Exchange transfusions or dialysis may be required.
Irbesartan is distributed into milk in rats; it is not known whether the drug is distributed into human milk or has any effects on the breast-fed infant or on milk production. Because of the potential risk in nursing infants, use of irbesartan in breast-feeding women is not recommended.
The manufacturer states that dosage adjustment in geriatric patients is not necessary.
In hypertension studies involving 4925 patients, 18.5% of patients were >=65 years of age and 3% were >=75 years of age. No substantial differences in safety or efficacy of irbesartan monotherapy have been observed in geriatric patients relative to younger adults, but increased sensitivity cannot be ruled out.
ICD codes
No ICD codes are available for this drug.
Formulary status
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Last reviewed · Source: First Databank (FDB) drug data
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