You are here: Urology Textbook > Drugs in Urology > Alpha-blocker > Doxazosin
Alpha-Blocker (2/5): Doxazosin
- Alpha-blocker (1/6): General pharmacology
- Alpha-blocker (2/6): Terazosin
- Alpha-blocker (3/6): Doxazosin
- Alpha-blocker (4/6): Tamsulosin
- Alpha-blocker (5/6): Alfuzosin
- Alpha-blocker (6/6): Silodosin
Review Literatur: (Chapple, 2004).
General Pharmacology of Doxazosin
Please see section general pharmacology of alpha-blocker.
Mechanism of Action of Doxazosin
Doxazosin is a non-selective alpha1-blocker with a long elimination half-life.
Indications for Doxazosin
- Treatment of lower urinary tract symptoms due to benign prostatic hyperplasia
- Treatment of arterial hypertension
Pharmacokinetics of Doxazosin
- Elimination half-life 22 h
Doxazosin: Mechanism of Action
Postsynaptic alpha1-blockade leads to:
- Arterial and venous vasodilation, hypotension
- Smooth muscle relaxation of the prostate, bladder neck and the urethra. Alpha-blocker improve the dynamic component of subvesical obstruction due to benign prostatic hyperplasia (BPH).
- Positive effect on the lipid metabolism by lowering cholesterol and triglycerides
Side Effects of Doxazosin
- Hypotension, orthostatic syncope, reflex tachycardia
- Stuffy nose
- Retrograde ejaculation
- Tachyphylaxis in the treatment of hypertension due to volume retention and peripheral edema.
- Dizziness, weakness
- Overall rate of side effects is between 10–30%
Contraindications of Doxazosin
Urological Contraindications:
Conservative treatment of BPH is not indicated, if surgical treatment is imperative: chronic urinary retention with renal failure, recurrent hematuria due to prostatic enlargement, recurrent infections and bladder stones.
Cardiac Contraindications:
Hypotension, mechanical heart failure (valvular, pulmonary embolism, pericarditis), congestive heart failure.
Other contraindications:
Doxazosin should be paused perioperatively for cataract surgery to prevent an intraoperative floppy iris syndrome.
Dosage of Doxazosin
The treatment of doxazosin should be started with a low dosage, such as 1 mg 1-0-0. The dosage can be increased each week to 2–4–8 mg 1-0-0, depending on treatment effect, side effects and blood pressure.
Terazosin | Index | Tamsulosin |
Index: 1–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
References
- Chapple 2004 CHAPPLE, C. R.:
- Pharmacological therapy of benign prostatic hyperplasia/lower urinary
tract symptoms: an overview for the practising clinician.
In: BJU Int
94 (2004), Nr. 5, S. 738–44
Deutsche Version: Doxazosin