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Two medicines, side by side

Irbesartan vs losartan

Irbesartan and losartan are both labeled for high blood pressure and chronic kidney disease. Drugs@FDA records approvals of irbesartan since 1997 and of losartan since 1995. Pharmacies paid $0.107 per irbesartan 150 mg tablet and $0.0327 per losartan potassium 50 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. How each works, in its label's words: Irbesartan, “Angiotensin II is a potent vasoconstrictor formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II).”; Losartan, “Angiotensin II [formed from angiotensin I in a reaction catalyzed by angiotensin converting enzyme (ACE, kininase II)] is a potent vasoconstrictor, the primary vasoactive hormone of the …”

Check it at the source: the irbesartan FDA label on DailyMed (effective August 6, 2026); the losartan FDA label on DailyMed (effective January 20, 2026).

Highlights of the irbesartan record

Irbesartan (Avapro) · label of August 6, 2026

Boxed warning

FETAL TOXICITY

When pregnancy is detected, discontinue irbesartan tablets as soon as possible [see Warnings and Precautions ( 5.1 ) and Use in Specific Populations ( 8.1 )].

Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus [see Warnings and Precautions ( 5.1 ) and Use in Specific Populations ( 8.1 )]. WARNING: FETAL TOXICITY See full prescribing information for complete boxed warning.

Used for

From the label: indications

Irbesartan is an angiotensin II receptor blocker (ARB) indicated for: • Treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. ( 1.1 ) Treatment of diabetic nephropathy in hypertensive patients with type 2 diabetes, an elevated serum creatinine, and proteinuria. […]

On the market

Earliest approval on file
September 30, 1997
Generic labelers
23 labelers
Pharmacy cost
$0.107 per tablet

Supply and safety

Shortage
No current entry
Recalls
10

Highlights of the losartan record

Losartan (Cozaar) · label of January 20, 2026

Boxed warning

FETAL TOXICITY When pregnancy is detected, discontinue COZAAR as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus [see Warnings and Precautions (5.1) ]. WARNING: FETAL TOXICITY See full prescribing information for complete boxed warning. When pregnancy is detected, discontinue COZAAR as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus.

Used for

From the label: indications

COZAAR is an angiotensin II receptor blocker (ARB) indicated 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. ( 1.1 ) Reduction of the risk of stroke in patients with hypertension and left ventricular hypertrophy. […]

On the market

Earliest approval on file
April 14, 1995
Generic labelers
43 labelers
Pharmacy cost
$0.0327 per tablet

Supply and safety

Shortage
No current entry
Recalls
77

Source: FDA drug labels via openFDA (Irbesartan label of August 6, 2026, Losartan label of January 20, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)

How do irbesartan and losartan differ on the record?

How each works, in its label's words: Irbesartan, “Angiotensin II is a potent vasoconstrictor formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II).”; Losartan, “Angiotensin II [formed from angiotensin I in a reaction catalyzed by angiotensin converting enzyme (ACE, kininase II)] is a potent vasoconstrictor, the primary vasoactive hormone of the …”

Both are in FDA's class angiotensin 2 receptor blockers.

Half-life, in each label's words: Irbesartan, “The terminal elimination half-life of irbesartan averages 11 to 15 hours.”; Losartan, “The terminal half-life of losartan is about 2 hours and of the metabolite is about 6-9 hours.”

Both labels carry a boxed warning; the records quote them.

Generics: irbesartan since 2012; losartan since 2010 (Drugs@FDA).

IrbesartanLosartan
Labeled forHigh blood pressure, Chronic kidney diseaseHigh blood pressure, Chronic kidney disease, Stroke prevention
Pharmacologic classAngiotensin 2 Receptor BlockerAngiotensin 2 Receptor Blocker
How it works (label)Angiotensin II is a potent vasoconstrictor formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II).Angiotensin II [formed from angiotensin I in a reaction catalyzed by angiotensin converting enzyme (ACE, kininase II)] is a potent vasoconstrictor, the primary vasoactive hormone of the renin-angiotensin system, and an important component …
Half-life (label)The terminal elimination half-life of irbesartan averages 11 to 15 hours.The terminal half-life of losartan is about 2 hours and of the metabolite is about 6-9 hours.
Earliest approval on file (Drugs@FDA)September 30, 1997April 14, 1995
First generic approvedMarch 30, 2012April 6, 2010
Generic labelers (NDC)23 labelers43 labelers
Pharmacy cost (NADAC, each one's most listed form; strengths differ)$0.107 per tablet (Irbesartan 150 mg tablet)$0.0327 per tablet (Losartan potassium 50 mg tablet)
12-month price change-8%+2%
Boxed warningYesYes
Shortage nowNo current entryNo current entry
Recalls recorded1077
FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used)44,400200,566
DEA schedulenonenone

Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)

What next?

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