II. Indications

  1. Hypertension
    1. Not first-line Antihypertensives, and avoid using as monotherapy (higher risk of CVA and CHF)
  2. Benign Prostatic Hypertrophy
    1. Selective Alpha-1a Antagonists (e.g. Tamsulosin) are preferred
  3. Medical Expulsive Therapy for Ureteral Stone
    1. Replaced by the preferred Selective Alpha-1a Antagonists (e.g. Tamsulosin)

III. Dosing

  1. Hypertension
    1. Start: 1 mg orally at bedtime and titrate dose (Maximum 16 mg/day)
  2. Benign Prostatic Hypertrophy (replaced by Selective Alpha-1a Antagonists)
    1. Start: 1 mg orally at bedtime and titrate every 1-2 weeks doubling dose, to a maximum of 8 mg at bedtime
    2. Extended release formulation (e.g. Cardura XL) 4 mg in am daily (may increase to 8 mg daily after 3-4 weeks)
  3. Medical Expulsive Therapy for Ureteral Stone (replaced by Selective Alpha-1a Antagonists)
    1. Extended release formulation (e.g. Cardura XL) 4 mg orally daily (not FDA approved)

IV. Safety

  1. Unknown safety in Pregnancy
  2. Unknown safety in Lactation

V. Mechanism

  1. See Alpha Adrenergic Receptor (Alpha-1 Antagonist)
  2. Peripheral Alpha-1 Adrenergic Antagonist
    1. Arterial and Venous Vasodilation

VII. Drug Interactions

  1. Strong CYP3A4 Inhibitors (e.g. Clarithromycin, Itraconazole)
    1. Risk of increased Doxazosin effects (e.g. Orthostatic Hypotension)

IX. References

  1. (2020) Med Lett Drugs Ther 62(1598): 73-80
  2. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 62-3
  3. Hamilton (2020) Tarascon Pocket Pharmacopoeia

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Related Studies

Cost: Medications

doxazosin (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
DOXAZOSIN MESYLATE 1 MG TAB Generic $0.09 each
DOXAZOSIN MESYLATE 2 MG TAB Generic $0.07 each
DOXAZOSIN MESYLATE 4 MG TAB Generic $0.09 each
DOXAZOSIN MESYLATE 8 MG TAB Generic $0.11 each

Ontology: Doxazosin (C0114873)

Definition (MSH) A prazosin-related compound that is a selective alpha-1-adrenergic blocker.
Definition (NCI) A quinazoline with antihypertensive and antineoplastic properties. Doxazosin is an alpha-adrenergic antagonist that selectively inhibits alpha-1 adrenergic receptors. Blockages of the alpha-1 adrenergic action on the vascular smooth muscles lead to a decrease in vascular resistance and antihypertensive activity. This agent also shows high affinity to alpha-1c adrenoceptor, the predominant functional type in the prostate, which may partially attribute to its effect in treatment of benign prostatic hyperplasia. Furthermore, doxazosin induces apoptosis in prostate cancer cells mediated through inhibition of protein kinase B (PKB)/Akt-signaling death receptor regulatory pathway.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D017292
SnomedCT 108556006, 372508002
LNC LP171393-4
English Doxazosin, Piperazine, 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-((2,3-dihydro-1,4-benzodioxin-2-yl)carbonyl)-, Doxazosin [Chemical/Ingredient], doxazosin (medication), alpha blockers doxazosin, doxazosin, DOXAZOSIN, Doxazosin (product), Doxazosin (substance)
Swedish Doxazosin
Czech doxazosin
Finnish Doksatsosiini
Russian DOKSAZOZIN, ДОКСАЗОЗИН
Japanese ドキサゾシン, ドキサゾシンメシレート, メシル酸ドキサゾシン
Spanish Doxazosina, Doxazosin, doxazosina (producto), doxazosina (sustancia), doxazosina
Portuguese Doxazossina, Doxazosin, Doxazosina
Polish Doksazosyna, Metylosulfonian doksazosyny
French Doxazosine
German Doxazosin
Italian Dossazosina

Ontology: Cardura (C0678136)

Definition (MSH) Trade name in United States.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D017292
English Carduran, cardura, carduran, Cardura, Cardular, Pfizer Brand of Doxazosin Mesylate, Zoxan