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Systematic (IUPAC) name
Clinical data
Trade names Hytrin
AHFS/Drugs.com monograph
MedlinePlus a693046
Legal status
Pharmacokinetic data
Protein binding 90-94%
Biological half-life 12 hours
CAS Number 63590-64-7 YesY
ATC code G04CA03
PubChem CID: 5401
DrugBank DB01162 YesY
ChemSpider 5208 YesY
UNII 8L5014XET7 YesY
KEGG D08569 YesY
Synonyms [4-(4-amino-6,7-dimethoxy-quinazolin-2-yl)piperazin-1-yl]-tetrahydrofuran-2-yl-methanone
Chemical data
Formula C19H25N5O4
Molecular mass 387.433 g/mol
 YesY (what is this?)  (verify)

Terazosin (marketed as Hytrin or Zayasel) is a selective alpha 1 antagonist used for treatment of symptoms of an enlarged prostate (BPH). It also acts to lower the blood pressure, and is therefore a drug of choice for men with hypertension and prostate enlargement. It is available in 1 mg, 2 mg, 5 mg or 10 mg doses.[1]

It works by blocking the action of adrenaline on smooth muscle of the bladder and the blood vessel walls.

Most common side effects include dizziness, drowsiness, headache, constipation, loss of appetite, fatigue, nasal congestion or dry eyes, but they generally go away after only a few days of use. Therapy should always be started with a low dose to avoid first dose phenomenon.[2] Sexual side effects are rare, but may include priapism or erectile dysfunction.


Terazocin synthesis:[3]

Reaction of piperazine with 2-furoyl chloride followed by catalytic hydrogenation of the furan ring leads to 2. This, when heated in the presence of 2-chloro-6,7-dimethoxyquinazolin-4-amine (1) undergoes direct alkylation to terazocin (3).

See also[edit]


  1. ^ Terazosin Hydrochloride Capsule, DailyMed, National Library of Medicine, National Institutes of Health
  2. ^ Hytrin (Terazosin Hcl) drug warnings and precautions - prescription drugs and medications at RxList
  3. ^ M. Winn, J. Kyncl, D. A. Dunnigan, and P. H. Jones, {{US Patent|4,026,894}} (1977); Chem. Abstr., 87; 68411m (1977).