Two medicines, side by side
Doxazosin vs clonidine
Doxazosin and clonidine are both labeled for high blood pressure. Drugs@FDA records approvals of doxazosin since 1990 and of clonidine since 1974. Pharmacies paid $0.0752 per doxazosin mesylate 1 mg tablet and $0.0241 per clonidine HCl 0.1 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. Clonidine's other strengths are brand-only: $1.53 per mL (Javadin 0.02 mg/mL solution). In FDA's classes, doxazosin is an alpha-adrenergic blocker and clonidine a central alpha-2 adrenergic agonist.
Check it at the source: the doxazosin FDA label on DailyMed (effective October 15, 2023); the clonidine FDA label on DailyMed (effective March 30, 2026).
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
Highlights of the clonidine record
Clonidine (Catapres) · label of March 30, 2026
Used for
From the label: indicationsClonidine hydrochloride tablets are indicated in the treatment of hypertension. Clonidine hydrochloride tablets may be employed alone or concomitantly with other antihypertensive agents.
On the market
- Earliest approval on file
- September 3, 1974
- Generic labelers
- 43 labelers
- Pharmacy cost
- $0.0241 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 16
Source: FDA drug labels via openFDA (Doxazosin label of October 15, 2023, Clonidine label of March 30, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do doxazosin and clonidine differ on the record?
In FDA's classes, doxazosin is an alpha-adrenergic blocker and clonidine a central alpha-2 adrenergic agonist.
Half-life, in each label's words: Doxazosin, “Excretion Plasma elimination of doxazosin is biphasic, with a terminal elimination half-life of about 22 hours.”; Clonidine, “Following intravenous administration, clonidine displays biphasic disposition with a distribution half-life of about 20 …”
Generics: doxazosin since 2000; clonidine since 1986 (Drugs@FDA).
| Doxazosin | Clonidine | |
|---|---|---|
| Labeled for | Enlarged prostate (BPH), High blood pressure | High blood pressure, ADHD, Pain |
| Pharmacologic class | alpha-Adrenergic Blocker | Central alpha-2 Adrenergic Agonist |
| How it works (label) | 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 … | n/a |
| Half-life (label) | Excretion Plasma elimination of doxazosin is biphasic, with a terminal elimination half-life of about 22 hours. | Following intravenous administration, clonidine displays biphasic disposition with a distribution half-life of about 20 minutes and an elimination half-life ranging from 12 to 16 hours. |
| Earliest approval on file (Drugs@FDA) | November 2, 1990 | September 3, 1974 |
| First generic approved | October 18, 2000 | July 1, 1986 |
| Generic labelers (NDC) | 29 labelers | 43 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0752 per tablet (Doxazosin mesylate 1 mg tablet) | $0.0241 per tablet (Clonidine HCl 0.1 mg tablet) |
| 12-month price change | -10% | -3% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 11 | 16 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 35,891 | 57,116 |
| 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 doxazosin
- every medicine labeled for the same conditions