Doxazosin
Unchecked
Alpha-1 adrenergic blocker (non-selective), Benign prostatic hyperplasia treatment, Antihypertensive
Doxazosin
Cardura, Cardura XL
Experience
No personal reports yet
No clinical reports yet
Log in to add your own experience.
Problems
No problems yet. Be the first to suggest one.
+ Add a problemTitration strategies
No titration strategies yet. Be the first to suggest one.
Effects
No effects listed yet. Be the first to suggest one.
Relevant anecdote
No anecdotes yet. Share a relevant one.
Relevant Literature
No literature entries yet.
Log in to submit relevant literature.
Summary
Classes
Common uses
Benign prostatic hyperplasia (LUTS)0, Hypertension (later-line; first-dose hypotension limits as monotherapy)0, PTSD-related nightmares (off-label, mostly prazosin in practice)0
Pharmacy
Starting dose
IR 1 mg PO at bedtime, titrate weekly; XL 4-8 mg PO daily
Preparations
1, 2, 4, 8 mg IR tablets; 4, 8 mg XL tablets
US FDA Max
16 mg/d (IR); 8 mg/d (XL)
Pharmacology
Routes
Oral
Onset
BP and symptomatic LUTS improvement within 1-2 weeks
Duration
24 hours
Half-life
~22 hours[1]
Bioavailability
~65% (oral)[1]
Pregnancy
Limited data; rarely indicated in pregnancy.[citation needed]
Legal status
Rx-only in US
Purported mechanism
Doxazosin is a non-selective α1 adrenergic receptor antagonist that relaxes vascular smooth muscle (lowering BP) and prostatic/bladder-neck smooth muscle (improving urodynamic flow); unlike tamsulosin, it lacks α1A subtype selectivity, producing more peripheral hypotension and the characteristic first-dose syncope that drives bedtime initiation.0 ALLHAT (2000) showed the doxazosin arm had significantly more heart failure than chlorthalidone, leading to the general practice of using α1 blockers as later-line antihypertensives rather than first-line[1]. Intraoperative floppy iris syndrome is a recognized class effect.
References
[edit | edit source]- ↑ 1.0 1.1 1.2 FDA Prescribing Information, Cardura (doxazosin mesylate), Pfizer, current revision. https://www.accessdata.fda.gov/drugsatfda_docs/label/2015/019668s032lbl.pdf