Dosing and uses of Avapro (irbesartan)
Adult dosage forms and strengths
tablet
- 75mg
- 150mg
- 300mg
Hypertension
150 mg/day PO initially; may be increased to 300 mg/day PO
Hypovolemia: 75 mg/day PO initially
Nephropathy in Type 2 Diabetes
75-300 mg/day PO
Dosage modifications
Mild-to-severe renal impairment: Dosage adjustment not necessary unless patient is hypovolemic
Dosing Considerations
Also given in combination with hydrochlorothiazide (Avalide)
Generally, adjust dosage monthly; adjust more aggressively in high-risk patients
Focal Segmental Glomerulosclerosis (Orphan)
Irbesartan and propagermanium: Orphan designation for treatment of focal segmental glomerulosclerosis
Sponsor
- Dimerix Bioscience Ltd; Level 2, 25 Flinders Lane; Melbourne
Pediatric dosage forms and strengths
tablet
- 75mg
- 150mg
- 300mg
Hypertension
<6 years: Safety and efficacy not established
6-12 years: 75 mg/day PO initially; not to exceed 150 mg/day
>12 years: 150 mg/day PO initially; may be increased to 300 mg/day PO
Avapro (irbesartan) adverse (side) effects
>10%
Hyperkalemia (19%)
1-10%
Dizziness (10%)
Upper respiratory tract infection (URTI) (9%)
Orthostatic hypotension (5%)
Fatigue (4%)
Diarrhea (3%)
Dyspepsia (2%)
Postmarketing Reports
Urticaria; angioedema (involving swelling of the face, lips, pharynx, or tongue); elevated liver function testresults; jaundice; hepatitis; hyperkalemia, and thrombocytopenia
Impaired renal function, including cases of renal failure, has been reported
Increased creatine phosphokinase (CPK) levels and rhabdomyolysis have been reported in patients receiving angiotensin-receptor blockers (ARBs)
Warnings
Black box warnings
Discontinue as soon as possible when pregnancy is detected; drug affects renin-angiotensin system, causing oligohydramnios, which may result in fetal injury or death
Contraindications
Hypersensitivity
Do not coadminister with aliskiren in patients with diabetes
Cautions
Angioedema, volume-depletion, severe congestive heart failure (CHF), hepatic or renal impairment, hypertrophic cardiomyopathy, aortic or mitral valve stenosis, surgery or anesthesia
Discontinue immediately if patient is pregnant; risk of congenital malformations (see Contraindications and Black box warnings)
Use with caution in renal artery stenosis; avoid in bilateral renal artery stenosis
Risk of hypotension or hyperkalemia
Dual blockade of the renin-angiotensin system with ARBs, angiotensin-converting enzyme (ACE) inhibitors, or aliskiren is associated with increased risk of hypotension, hyperkalemia, and altered renal function (including acute renal failure) in comparison with monotherapy
Risk of heart failure-related morbidity; concomitant treatment with ACE inhibitors and beta-adrenergic agents is not recommended
Pregnancy and lactation
Pregnancy category: 1st trimester, C; 2nd and 3rd trimesters, d
Lactation: Potential harm to nursing infant; discontinue drug, or do not nurse
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Avapro (irbesartan)
Mechanism of action
Angiotensin II receptor blocker; inhibits vasoconstrictor and aldosterone-secreting effects of angiotensin II
Absorption
Bioavailability: 60-80%
Onset: 1-2 hr (peak effect)
Duration: 24 hr
Peak plasma time: 1.5-2 hr
Distribution
Protein bound: 90%
Vd: 53-93 L
Metabolism
Metabolized by hepatic CYP2C9 and minimally by CYP3A4
Metabolites: Irbesartan glucuronide conjugate (inactive)
Elimination
Half-life: 11-15 hr
Renal clearance: 3-3.5 mL/min
Total body clearance: 157-176 mL/min
Excretion: Feces (80%), urine (20%)
