Two medicines, side by side
Silodosin vs doxazosin
Silodosin and doxazosin are both labeled for enlarged prostate (bph). Drugs@FDA records approvals of silodosin since 2008 and of doxazosin since 1990. Pharmacies paid $0.319 per silodosin 8 mg capsule and $0.0752 per doxazosin mesylate 1 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: Silodosin, “Silodosin is a selective antagonist of post-synaptic alpha-1 adrenoreceptors, which are located in the human prostate, bladder base, bladder neck, prostatic capsule, and prostatic urethra.”; Doxazosin, “Benign Prostatic Hyperplasia (BPH) The symptoms associated with benign prostatic hyperplasia (BPH), such as urinary frequency, nocturia, weak stream, hesitancy, and incomplete emptying are related to …”
Check it at the source: the silodosin FDA label on DailyMed (effective April 15, 2026); the doxazosin FDA label on DailyMed (effective October 15, 2023).
Highlights of the silodosin record
Silodosin (Rapaflo) · label of April 15, 2026
Used for
From the label: indicationsSilodosin, a selective alpha-1 adrenergic receptor antagonist, is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH) [see Clinical Studies (14 ) ]. Silodosin capsules are not indicated for the treatment of hypertension. Silodosin, an alpha-1 adrenergic receptor antagonist, is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). […]
On the market
- Earliest approval on file
- October 8, 2008
- Generic labelers
- 13 labelers
- Pharmacy cost
- $0.319 per capsule
Supply and safety
- Shortage
- No current entry
- Recalls
- 1
Highlights of the doxazosin record
Doxazosin (Cardura) · label of October 15, 2023
Used for
From the label: indicationsCARDURA is an alpha 1 adrenergic antagonist indicated for: • Signs and symptoms of Benign Prostatic Hyperplasia (BPH) ( 1.1 ) • Treatment of Hypertension ( 1.2 ) 1.1 Benign Prostatic Hyperplasia (BPH) CARDURA is indicated for the treatment of the signs and symptoms of BPH. 1.2 Hypertension CARDURA is indicated for the treatment of hypertension, to lower blood pressure. […]
On the market
- Earliest approval on file
- November 2, 1990
- Generic labelers
- 29 labelers
- Pharmacy cost
- $0.0752 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 11
Source: FDA drug labels via openFDA (Silodosin label of April 15, 2026, Doxazosin label of October 15, 2023); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do silodosin and doxazosin differ on the record?
How each works, in its label's words: Silodosin, “Silodosin is a selective antagonist of post-synaptic alpha-1 adrenoreceptors, which are located in the human prostate, bladder base, bladder neck, prostatic capsule, and prostatic urethra.”; Doxazosin, “Benign Prostatic Hyperplasia (BPH) The symptoms associated with benign prostatic hyperplasia (BPH), such as urinary frequency, nocturia, weak stream, hesitancy, and incomplete emptying are related to …”
Both are in FDA's class alpha-adrenergic blockers.
Half-life, in each label's words: Silodosin, “KMD-3213G, which has been shown in vitro to be active, has an extended half-life (approximately 24 hours) and reaches …”; Doxazosin, “Excretion Plasma elimination of doxazosin is biphasic, with a terminal elimination half-life of about 22 hours.”
Generics: silodosin since 2017; doxazosin since 2000 (Drugs@FDA).
| Silodosin | Doxazosin | |
|---|---|---|
| Labeled for | Enlarged prostate (BPH) | Enlarged prostate (BPH), High blood pressure |
| Pharmacologic class | alpha-Adrenergic Blocker | alpha-Adrenergic Blocker |
| How it works (label) | Silodosin is a selective antagonist of post-synaptic alpha-1 adrenoreceptors, which are located in the human prostate, bladder base, bladder neck, prostatic capsule, and prostatic urethra. | Benign Prostatic Hyperplasia (BPH) The symptoms associated with benign prostatic hyperplasia (BPH), such as urinary frequency, nocturia, weak stream, hesitancy, and incomplete emptying are related to two components, anatomical (static) and … |
| Half-life (label) | KMD-3213G, which has been shown in vitro to be active, has an extended half-life (approximately 24 hours) and reaches plasma exposure (AUC) approximately four times greater than that of silodosin. | Excretion Plasma elimination of doxazosin is biphasic, with a terminal elimination half-life of about 22 hours. |
| Earliest approval on file (Drugs@FDA) | October 8, 2008 | November 2, 1990 |
| First generic approved | March 31, 2017 | October 18, 2000 |
| Generic labelers (NDC) | 13 labelers | 29 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.319 per capsule (Silodosin 8 mg capsule) | $0.0752 per tablet (Doxazosin mesylate 1 mg tablet) |
| 12-month price change | -29% | -10% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 1 | 11 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 3,956 | 35,891 |
| 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 silodosin
- every medicine labeled for the same conditions