Two medicines, side by side
Guanfacine vs losartan
Guanfacine and losartan are both labeled for high blood pressure. Drugs@FDA records approvals of guanfacine since 1986 and of losartan since 1995. Pharmacies paid $0.147 per guanfacine 1 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. In FDA's classes, guanfacine is a central alpha-2 adrenergic agonist and losartan an angiotensin 2 receptor blocker.
Check it at the source: the guanfacine FDA label on DailyMed (effective June 23, 2025); the losartan FDA label on DailyMed (effective January 20, 2026).
Highlights of the guanfacine record
Guanfacine (Intuniv) · label of June 23, 2025
Used for
From the label: indicationsINTUNIV ® is indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) as monotherapy and as adjunctive therapy to stimulant medications [see Clinical Studies (14) ]. INTUNIV is a central alpha 2A -adrenergic receptor agonist indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) as monotherapy and as adjunctive therapy to stimulant medications ( 1 , 14 ).
On the market
- Earliest approval on file
- October 27, 1986
- Generic labelers
- 36 labelers
- Pharmacy cost
- $0.147 per tablet
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 1
Highlights of the losartan record
Losartan (Cozaar) · label of January 20, 2026
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: indicationsCOZAAR 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 (Guanfacine label of June 23, 2025, Losartan label of January 20, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do guanfacine and losartan differ on the record?
In FDA's classes, guanfacine is a central alpha-2 adrenergic agonist and losartan an angiotensin 2 receptor blocker.
How each works, in its label's words: Guanfacine, “Guanfacine is a central alpha 2A -adrenergic receptor agonist.”; 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 …”
Only the losartan label carries a boxed warning.
Generics: guanfacine since 1995; losartan since 2010 (Drugs@FDA).
| Guanfacine | Losartan | |
|---|---|---|
| Labeled for | ADHD, High blood pressure | High blood pressure, Chronic kidney disease, Stroke prevention |
| Pharmacologic class | Central alpha-2 Adrenergic Agonist | Angiotensin 2 Receptor Blocker |
| How it works (label) | Guanfacine is a central alpha 2A -adrenergic receptor agonist. Guanfacine is not a central nervous system (CNS) stimulant. The mechanism of action of guanfacine in ADHD is not known. | 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) | n/a | 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) | October 27, 1986 | April 14, 1995 |
| First generic approved | October 17, 1995 | April 6, 2010 |
| Generic labelers (NDC) | 36 labelers | 43 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.147 per tablet (Guanfacine 1 mg tablet) | $0.0327 per tablet (Losartan potassium 50 mg tablet) |
| 12-month price change | -5% | +2% |
| Boxed warning | No | Yes |
| Shortage now | A presentation being discontinued | No current entry |
| Recalls recorded | 1 | 77 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 7,825 | 200,566 |
| DEA schedule | none | none |
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?
- Alternatives to guanfacine
- every medicine labeled for the same conditions