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Related to Cardura: Cardura XL

doxazosin mesylate

Cardozin XL (UK), Cardura, Cardura XL, Doxadura (UK)

Pharmacologic class: Sympatholytic, peripherally acting antiadrenergic

Therapeutic class: Antihypertensive

Pregnancy risk category C


Blocks alpha1-adrenergic receptors, promoting vasodilation. Also reduces urethral resistance, relieving obstruction and improving urine flow and other symptoms of benign prostatic hypertrophy (BPH).


Tablets: 1 mg, 2 mg, 4 mg, 8 mg

Tablets (extended-release): 4 mg, 8 mg

Indications and dosages


Adults: 1 mg P.O. once daily. May increase dosage gradually q 2 weeks, up to 2 to 16 mg daily, as needed.


Adults: 1 mg P.O. once daily. May increase dosage gradually, up to 8 mg daily, as needed. Or, initially 4 mg (extended-release) P.O. daily. May increase dosage to 8 mg daily, as needed, at 3- to 4-week intervals.

Off-label uses

• Pheochromocytoma

• Syndrome X


• Hypersensitivity to drug, its components, or quinazoline derivatives


Use cautiously in:

• renal or mild or moderate hepatic impairment, coronary insufficiency, or preexisting severe GI narrowing

• severe hepatic impairment (extended-release form not recommended)

• intraoperative floppy iris syndrome

• concurrent use of strong CYP3A4 inhibitor (such as atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, or voriconazole), phosphodiesterase-5 (PDE-5) inhibitors

• elderly patients

• pregnant or breastfeeding patients (extended-release form not recommended in breastfeeding patients)

• children (safety not established).


• Give initial immediate-release dose at bedtime to minimize orthostatic hypotension and syncope.

• Give initial extended-release dose at breakfast.

• Be aware that extended-release tablets aren't indicated for hypertension.

• Be aware that prostate carcinoma should be ruled out before giving drug for BPH.

• Know that incidence of orthostatic hypotension increases greatly when daily dosage exceeds 4 mg and that it usually occurs within 6 hours of administration.

If new or worsening signs or symptoms of angina pectoris occur, discontinue drug.

Adverse reactions

CNS: dizziness, vertigo, headache, depression, drowsiness, fatigue, nervousness, weakness, asthenia

CV: orthostatic hypotension, chest pain, palpitations, tachycardia, arrhythmias

EENT: abnormal or blurred vision, conjunctivitis, epistaxis, rhinitis, pharyngitis

GI: nausea, vomiting, diarrhea, constipation, abdominal discomfort, flatulence, dry mouth

GU: decreased libido, sexual dysfunction

Respiratory: dyspnea

Musculoskeletal: joint pain, arthritis, gout, myalgia

Skin: flushing, rash, pruritus

Other: edema


Drug-drug. Clonidine, nitrates, other antihypertensives: decreased antihypertensive effect

Drugs that reduce GI motility leading to markedly prolonged GI retention times (such as anticholinergics): increased systemic exposure to doxazosin

PDE-5 inhibitors: increased risk of symptomatic hypotension

Drug-diagnostic tests. Neutrophils, white blood cells: decreased counts

Drug-food. Any food: increased drug plasma Cmax (extended-release form)

Patient monitoring

• Monitor blood pressure with patient lying down and standing up every 2 to 6 hours after initial dose or after a dosage increase (when orthostatic hypotension is most likely to occur).

Patient teaching

• Tell patient to swallow extended-release tablets whole and not to chew, divide, cut, or crush them.

• Caution patient not to drive or perform other activities requiring alertness for 12 to 24 hours after first dose.

• Tell patient to move slowly when sitting up or standing, to avoid dizziness or light-headedness from sudden blood pressure decrease.

• Advise patient to report episodes of dizziness or palpitations.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


(dox-ay-zoe-sin) ,


(trade name),

Cardura XL

(trade name)


Therapeutic: antihypertensives
Pharmacologic: peripherally acting antiadrenergics
Pregnancy Category: C


Hypertension (alone or with other agents) (immediate-release only).Symptomatic benign prostatic hyperplasia (BPH).


Dilates both arteries and veins by blocking postsynaptic alpha1-adrenergic receptors.

Therapeutic effects

Lowering of BP.
Increased urine flow and decreased symptoms of BPH.


Absorption: Well absorbed following oral administration.
Distribution: Probably enters breast milk; rest of distribution unknown.
Protein Binding: 98–99%.
Metabolism and Excretion: Extensively metabolized by the liver.
Half-life: 22 hr.

Time/action profile

PO†1–2 hr2–6 hr24 hr
PO-XL‡5 wkunknownunknown
† Antihypertensive effect‡ Improved urinary flow and BPH symptoms


Contraindicated in: Hypersensitivity.
Use Cautiously in: Hepatic dysfunction;Gastrointestinal narrowing (XL only); Geriatric: Appears on Beers list. Geriatric patients are at ↑ risk for hypotension; Obstetric / Lactation / Pediatric: Safety not established;Patients undergoing cataract surgery (↑ risk of intraoperative floppy iris syndrome).

Adverse Reactions/Side Effects

Central nervous system

  • dizziness (most frequent)
  • headache (most frequent)
  • depression
  • drowsiness
  • fatigue
  • nervousness
  • weakness

Ear, Eye, Nose, Throat

  • abnormal vision
  • blurred vision
  • conjunctivitis
  • epistaxis
  • intraoperative floppy iris syndrome


  • dyspnea


  • first-dose orthostatic hypotension (most frequent)
  • arrhythmias
  • chest pain
  • edema
  • palpitations


  • abdominal discomfort
  • constipation
  • diarrhea
  • dry mouth
  • flatulence
  • nausea
  • vomiting


  • ↓ libido
  • priapism
  • sexual dysfunction


  • flushing
  • rash
  • urticaria


  • arthralgia
  • arthritis
  • gout
  • myalgia


Drug-Drug interaction

↑ risk of hypotension with sildenafil, tadalafil, vardenafil, other antihypertensives, nitrates, or acute ingestion of alcohol.NSAIDs, sympathomimetics, or estrogens may ↓ effects of antihypertensive therapy.


Oral (Adults) —1 mg once daily, may be gradually ↑ at 2-wk intervals to 2–16 mg/day; incidence of postural hypotension greatly ↑ at doses >4 mg/day. BPH—1 mg once daily, may be gradually increased to 8 mg/day.
Benign Prostatic Hyperplasia
Oral (Adults) Immediate release—1 mg once daily, may be ↑ every 1–2 wk up to 8 mg/day; Extended release—4 mg once daily (with breakfast), may be ↑ in 3–4 wk to 8 mg/day.

Availability (generic available)

Tablets: 1 mg, 2 mg, 4 mg, 8 mg Cost: Generic — 1 mg $60.00 / 100, 2 mg $79.89 / 100, 4 mg $85.34 / 100, 8 mg $60.41 / 100
Extended-release tablets: 4 mg, 8 mg Cost: 4 mg $84.62 / 30, 8 mg $88.90 / 30

Nursing implications

Nursing assessment

  • Monitor BP and pulse 2–6 hr after first dose, with each increase in dose, and periodically during therapy. Report significant changes.
    • Assess for first-dose orthostatic hypotension and syncope. Incidence may be dose related. Observe patient closely during this period and take precautions to prevent injury.
    • Monitor intake and output ratios and daily weight, and assess for edema daily, especially at beginning of therapy. Report weight gain or edema.
  • BPH: Assess patient for symptoms of prostatic hyperplasia (urinary hesitancy, feeling of incomplete bladder emptying, interruption of urinary stream, impairment of size and force of urinary stream, terminal urinary dribbling, straining to start flow, dysuria, urgency) prior to and periodically during therapy.

Potential Nursing Diagnoses

Impaired urinary elimination (Indications)
Risk for injury (Side Effects)


  • Do not confuse Cardura with Coumadin.
  • Oral: Administer daily dose at bedtime.
    • XL tablets should be swallowed whole; do not break, crush, or chew.
  • Hypertension: May be administered concurrently with a diuretic or other antihypertensive.

Patient/Family Teaching

  • Emphasize the importance of continuing to take this medication, even if feeling well. Instruct patient to take medication at the same time each day. Take missed doses as soon as remembered unless almost time for next dose. Do not double doses.
    • May cause drowsiness or dizziness. Advise patient to avoid driving or other activities requiring alertness until response to medication is known.
    • Caution patient to change positions slowly to decrease orthostatic hypotension. May cause syncopal episodes, especially within first 24 hr of therapy, with dose increase, and with resumption of therapy after interruption.
    • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to avoid concurrent use of alcohol or OTC medications and herbal products, especially cold preparations, without consulting health care professional, especially cough, cold, or allergy remedies.
    • Advise male patient to notify health care professional if priapism or erection of longer than 4 hr occurs; may lead to permanent impotence if not treated.
    • Advise female patient to notify health care professional if pregnancy is planned or suspected or if breast feeding.
    • Emphasize the importance of follow-up visits to determine effectiveness of therapy.
  • Hypertension: Instruct patient and family on proper technique for BP monitoring. Advise them to check BP at least weekly and report significant changes.
    • Encourage patient to comply with additional interventions for hypertension (weight reduction, low-sodium diet, smoking cessation, moderation of alcohol consumption, regular exercise, and stress management).

Evaluation/Desired Outcomes

  • Decrease in BP without appearance of side effects.
  • Decrease in urinary symptoms of BPH.
Drug Guide, © 2015 Farlex and Partners


A trademark for the drug doxazosin mesylate.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


Doxazosin mesylate, see there.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
[alpha]-Antagonists Tamsulosin (Flomax) Terazosin (Hytrin) Doxazosin (Cardura)
"When Pfizer's Cardura XL was not approved [by the year-end date], we exercised our right to terminate the Pfizer contract.
Pfizer has publicly stated that it supported the NHLBI's decision to stop the Cardura arm of the study.
Its important products include Norvasc (cardiovascular), Zoloft (antidepressant), Zithromax (antibiotic), Lipitor (cholesterol), Aricept (Alzheimer's), Cardura (cardiovascular), Diflucan (antifungal), Zyrtec (antihistamine), Viagra (impotence) and Celebrex/Bextra (rheumatoid arthritis and osteoarthritis).
Older, nonselective alpha-blockers--doxazosin (Cardura) and terazosin (Hytrin)--relax these muscles and those surrounding blood vessels elsewhere.
The ALLHAT trial, a double-blind RCT of 42,448 high-risk hypertensive patients aged >55 years, compared chlorthalidone (a thiazide-type diuretic) with amlodipine (Norvasc), lisinopril (Prinivil, Zestril), or doxazosin (Cardura).
strengths; four dosage levels of doxazosin mesylate tablets (a generic version of Pfizer Inc.'s heart drug Cardura); and bisoprolol fumarate and hydrochlorothiazide tablets in concentrations of 2.5 mg./6.25 mg., 5 mg./6.25 mg.
Other drugs used to treat Raynaud's include losartan potassium (Cozaar), doxazosin (Cardura), prazosin ( Minipress ) and pentoxifylline (Trental), a blood thinner .
Although older, nonselective alpha-blockers--doxazosin (Cardura) and terazosin (Hytrin)--require blood pressure monitoring and dose adjustments and are slightly more likely to cause lightheadedness, dizziness and fatigue than their selective counterparts, they're equally as effective and may be less costly, Dr.
TABLE Potentially inappropriate medications in the elderly MEDICATION POTENTIAL ADVERSE EFFECT Meperidine (Demerol) Confusion Propoxyphene (Darvon) CNS effects Diphenhydramine (Benadryl) Sedation Long-term use of NSAIDs GI bleeding Amitriptyline (Elavil) Sedation/anticholinergic effects Methyldopa (Aldomet) Bradycardia Diazepam (Valium) Sedation Cimetidine (Tagamet) Confusion Nitrofurantoin (Macrodantin) Potential renal insufficiency Clonidine (Catapres) Hypotension/CNS effects Disopyramide (Norpace) Heart failure Ketorolac (Toradol) GI bleeding Short-acting nifedipine (Procardia) Hypotension Doxazosin (Cardura) Hypotension
Other key drugs are Viagra, for impotence; Celebrex, for rheumatoid arthritis and osteoarthritis; Zithromax, an antibiotic; Aricept, for Alzheimer's; Cardura, a cardiovascular medication; Diflucan, an antifungal; and Zyrtec, an antihistamine.
Men who take alpha-blockers--doxazosin (Cardura) and terazosin (Hytrin) are examples--also may be at risk for a drop in blood pressure and should use PDE-5 inhibitors with caution.