Dosing & Uses
Dosage Forms & Strengths
tablet
- 1mg
- 2mg
- 4mg
- 8mg
tablet, extended release
- 4mg
- 8mg
Hypertension
1 mg PO qDay in AM or PM; may titrate by doubling daily dose up to 16 mg qDay based on blood pressure response; usual dosage range is 1-2 mg qDay; if therapy is discontinued for several days, initiate dose at 1 mg qDay and titrate using initial dosing regimen
Extended release: Not indicated for hypertension
Benign Prostatic Hyperplasia
Immediate release: 1 mg PO qDay; may titrate by doubling daily dose at 1-2 week intervals to maximum 8 mg/day
If therapy is discontinued for several days, initiate dose at 1 mg qDay and titrate using initial dosing regimen
Extended release: 4 mg PO qDay; may titrate based on response and tolerability every 3-4 weeks to 8 mg PO qDay
If therapy is discontinued for several days, initiate dose at 1 mg qDay and titrate using initial dosing regimen
Dosing Modifications
Hepatic impairment: Use with caution in mild-to-moderate hepatic dysfunction; do not use in severe impairment
Renal impairment: Labeling from manufacturer does not provide dosage adjustment information
Dosing Considerations
Give first dose and increase at bedtime to avoid syncope
Dosage Forms & Strengths
tablet
- 1mg
- 2mg
- 4mg
- 8mg
Hypertension (Off-label)
Immediate release: 1-4 mg PO once daily in AM or PM
Hypertension
Avoid use for hypertension; high risk of orthostatic hypotension (Beers criteria); if used, lower initial dosages and gradual adjustments are recommended
Immediate release: 0.5-16 mg PO once daily in AM or PM
Extended release: Not indicated for hypertension
Benign Prostatic Hyperplasia
Immediate release: 1-8 mg/day PO
Extended release: 4 mg/day PO initially at breakfast; may be increased to no more than 8 mg/day PO
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (4)
- sildenafil
sildenafil increases effects of doxazosin by pharmacodynamic synergism. Avoid or Use Alternate Drug. Risk of hypotension; separate sildenafil >25mg from alpha blocker by 4hr.
- tamsulosin
doxazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.
- vardenafil
vardenafil increases effects of doxazosin by pharmacodynamic synergism. Contraindicated. Risk of hypotension.
- yohimbe
yohimbe increases effects of doxazosin by pharmacodynamic synergism. Contraindicated.
Monitor Closely (92)
- acebutolol
doxazosin and acebutolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.
- aceclofenac
aceclofenac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- acemetacin
acemetacin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- aldesleukin
aldesleukin increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.
- alfuzosin
alfuzosin and doxazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- amifostine
amifostine, doxazosin. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.
- amlodipine
doxazosin and amlodipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- asenapine
asenapine and doxazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- aspirin
aspirin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- aspirin rectal
aspirin rectal decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- aspirin/citric acid/sodium bicarbonate
aspirin/citric acid/sodium bicarbonate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- atenolol
doxazosin and atenolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- avanafil
avanafil increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.
- betaxolol
doxazosin and betaxolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- bisoprolol
doxazosin and bisoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- captopril
captopril, doxazosin. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response. Both drugs lower blood pressure. Monitor blood pressure.
- carbidopa
carbidopa increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Therapy with carbidopa, given with or without levodopa or carbidopa-levodopa combination products, is started, dosage adjustment of the antihypertensive drug may be required.
- carvedilol
doxazosin and carvedilol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- celecoxib
celecoxib decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- celiprolol
doxazosin and celiprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- choline magnesium trisalicylate
choline magnesium trisalicylate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- clevidipine
doxazosin and clevidipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- clonidine
clonidine, doxazosin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive sympatholytic action may worsen sinus node dysfunction and atrioventricular (AV) block.
- diclofenac
diclofenac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- diflunisal
diflunisal decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- diltiazem
doxazosin and diltiazem both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- duvelisib
duvelisib will increase the level or effect of doxazosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.
- enalapril
enalapril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- esmolol
doxazosin and esmolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.
- etodolac
etodolac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- felodipine
doxazosin and felodipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- fenoprofen
fenoprofen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- flurbiprofen
flurbiprofen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- fosinopril
fosinopril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- ibuprofen
ibuprofen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- ibuprofen IV
ibuprofen IV decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- iloperidone
iloperidone increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor.
- imidapril
imidapril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- indomethacin
indomethacin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- isradipine
doxazosin and isradipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- ketoprofen
ketoprofen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- ketorolac
ketorolac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- ketorolac intranasal
ketorolac intranasal decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- labetalol
doxazosin and labetalol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- levodopa
levodopa increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Consider decreasing dosage of antihypertensive agent.
- lisinopril
lisinopril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- lornoxicam
lornoxicam decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- lurasidone
lurasidone increases effects of doxazosin by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed.
- maraviroc
maraviroc, doxazosin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of orthostatic hypotension.
- meclofenamate
meclofenamate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- mefenamic acid
mefenamic acid decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- meloxicam
meloxicam decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- metoprolol
doxazosin and metoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- moexipril
moexipril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- moxisylyte
doxazosin and moxisylyte both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- nabumetone
nabumetone decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- nadolol
doxazosin and nadolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- naproxen
naproxen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- nebivolol
doxazosin and nebivolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- nicardipine
doxazosin and nicardipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- nifedipine
doxazosin and nifedipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- nirmatrelvir/ritonavir
nirmatrelvir/ritonavir will increase the level or effect of doxazosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for increased bradycardia, hypotension, or dizziness. If needed, temporarily pause the antihypertensive drug.
- nisoldipine
doxazosin and nisoldipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- nitroglycerin rectal
nitroglycerin rectal, doxazosin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Observe for possible additive hypotensive effects during concomitant use. .
- oxaprozin
oxaprozin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- oxymetazoline topical
oxymetazoline topical increases and doxazosin decreases sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- parecoxib
parecoxib decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- penbutolol
doxazosin and penbutolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- perindopril
perindopril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- phenoxybenzamine
doxazosin and phenoxybenzamine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- phentolamine
doxazosin and phentolamine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- pindolol
doxazosin and pindolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- piroxicam
piroxicam decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- prazosin
doxazosin and prazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- propranolol
doxazosin and propranolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.
- pseudoephedrine
pseudoephedrine decreases effects of doxazosin by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- quinapril
quinapril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- ramipril
ramipril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- salicylates (non-asa)
salicylates (non-asa) decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- salsalate
salsalate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- silodosin
doxazosin and silodosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- sotalol
doxazosin and sotalol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.
- sulfasalazine
sulfasalazine decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- sulindac
sulindac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- tadalafil
tadalafil increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.
- terazosin
doxazosin and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- timolol
doxazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- tolfenamic acid
tolfenamic acid decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- tolmetin
tolmetin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- trandolapril
trandolapril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- verapamil
doxazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- zotepine
doxazosin and zotepine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
Minor (7)
- brimonidine
brimonidine increases effects of doxazosin by pharmacodynamic synergism. Minor/Significance Unknown.
- butcher's broom
doxazosin, butcher's broom. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- ethanol
doxazosin, ethanol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension, esp. in Asian pts.
- phenylephrine
doxazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- phenylephrine PO
doxazosin, phenylephrine PO. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- tizanidine
tizanidine increases effects of doxazosin by pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension.
- treprostinil
treprostinil increases effects of doxazosin by pharmacodynamic synergism. Minor/Significance Unknown.
Adverse Effects
>10%
Dizziness (5-19%)
Fatigue (8-12%)
Headache (6-10%)
1-10%
Vertigo (7%)
Upper respiratory tract infection (URTI) (5%)
Edema (3-4%)
Rhinitis (3%)
Dyspnea (1-3%)
Abdominal pain (2%)
Hypotension (1-2%)
Nausea (1-2%)
Orthostatic hypotension (dose related) (0.3-2%)
Anxiety (1%)
Palpitations (1%)
Postmarketing experience
Autonomic Nervous System: Priapism
Cardiovascular System: Cerebrovascular accidents, dizziness postural, myocardial infarction
Central and Peripheral Nervous System: Hypoesthesia, paresthesia
Endocrine System: Gynecomastia
Gastrointestinal System: Gastrointestinal obstruction, vomiting
General Body System: Fatigue, hot flushes, malaise
Heart Rate/Rhythm: Bradycardia, cardiac arrhythmias
Hematopoietic: Leukopenia, purpura, thrombocytopenia
Liver/Biliary System: Abnormal liver function tests, hepatitis, hepatitis cholestatic, jaundice
Musculoskeletal System: Muscle cramps, muscle weakness
Psychiatric: Agitation, anorexia, nervousness
Respiratory System: Bronchospasm aggravated
Skin Disorders: Alopecia, urticaria, skin rash, pruritus
Special Senses: Blurred vision, intraoperative Floppy Iris Syndrome
Urinary System: Hematuria, micturition disorder, micturition frequency, nocturia, polyuria
Warnings
Contraindications
Hypersensitivity to doxazosin or other quinazolines
Cautions
Use with caution in liver disease or recent cerebrovascular accident (CVA)
Rule out prostate cancer before initiating therapy
May cause first-dose syncope or sudden loss of consciousness
Risk of orthostatic hypotension (dose dependent)
Potential for hypotension, dry mouth, and urinary complications in elderly
Priapism (painful penile erection, sustained for hours and unrelieved by sexual intercourse or masturbation) rarely reported (probably less frequently than once in every several thousand patients), with alpha-1 antagonists, including doxazosin; because condition can lead to permanent impotence if not promptly treated, patients must be advised about seriousness of condition
Concomitant use of other antihypertensives (additive hypotensive effects)
Extended-release form not indicated for hypertension
Concomitant administration of immediate-release form with a phosphodiesterase-5 (PDE-5) inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension
May increase the risk of heart failure by exacerbating underlying myocardial dysfunction by β1Receptor stimulation with increases in renin and aldosterone
May cause CNS depression, which may impair ability to operate heavy machinery and performing tasks that require mental alertness
Allergic reactions, including urticaria, rash, angioedema, pruritus, and respiratory symptoms may occur
Intraoperative floppy iris syndrome reported in cataract surgery patients who received alph1-blocker therapy; discontinuing alpha-blocker therapy prior to surgery does not appear to be of benefit
Decreases in white blood cells (WBC) and neutrophil count reported; WBC and neutrophil counts returned to normal following discontinuation of therapy
Pregnancy & Lactation
Pregnancy
Not indicated for use in females or for the treatment of hypertension; the limited available data in pregnant women are not sufficient to inform a drug-associated risk for major birth defects and miscarriage; no adverse developmental outcomes were observed in animal reproduction studies with oral administration to pregnant rats and rabbits at doses of up to 10 and 4 times, respectively, the 12 mg/day recommended dose; postnatal development was delayed in rats at a dose of 8 times the 12 mg/day recommended dose
Lactation
Present in human milk; there is no information on effects on breastfed infant or effects on milk production
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Hypertension: Blocks postsynaptic alpha1 receptors; alpha blockade causes arterial, arteriolar, and venous dilation; decreases total peripheral resistance and blood pressure
Benign prostatic hyperplasia (BPH): Blocks alpha1 receptors in prostatic stromal and bladder tissues; reduces sympathetic tone-induced urethral stricture responsible for BPH symptoms
Absorption
Bioavailability: Immediate release, 65%; extended release, 54-59%
Onset (antihypertensive response): Peak, 4-8 hr
Onset (BPH response): Initial, 2 wk; peak, 4-6 weeks
Duration: 24 hr
Peak plasma time: 2-3 hr
Distribution
Protein bound: 99%
Vd: 1-3.4 L/kg
Metabolism
Metabolized extensively in liver
Metabolites: 6- and 7-O-demethyl metabolites, 6'- and 7'-hydroxy metabolites, other minor metabolites (activity unknown)
Elimination
Half-life: Immediate release, 22 hr; extended release, 15-19 hr
Dialyzable: HD, no
Total body clearance: 83-140 mL/min
Excretion: Feces (65%), urine (0.6-9%)
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| Cardura XL oral - | 8 mg tablet |  | |
| Cardura XL oral - | 4 mg tablet |  | |
| doxazosin oral - | 2 mg tablet |  | |
| doxazosin oral - | 8 mg tablet |  | |
| doxazosin oral - | 8 mg tablet |  | |
| doxazosin oral - | 4 mg tablet |  | |
| doxazosin oral - | 2 mg tablet |  | |
| doxazosin oral - | 2 mg tablet |  | |
| doxazosin oral - | 4 mg tablet |  | |
| doxazosin oral - | 1 mg tablet |  | |
| doxazosin oral - | 4 mg tablet |  | |
| doxazosin oral - | 8 mg tablet |  | |
| doxazosin oral - | 8 mg tablet |  | |
| doxazosin oral - | 1 mg tablet |  | |
| doxazosin oral - | 1 mg tablet |  | |
| doxazosin oral - | 1 mg tablet |  | |
| doxazosin oral - | 2 mg tablet |  | |
| doxazosin oral - | 2 mg tablet |  | |
| doxazosin oral - | 4 mg tablet |  | |
| doxazosin oral - | 2 mg tablet |  | |
| doxazosin oral - | 1 mg tablet |  | |
| doxazosin oral - | 4 mg tablet |  | |
| doxazosin oral - | 1 mg tablet |  | |
| doxazosin oral - | 2 mg tablet |  | |
| doxazosin oral - | 4 mg tablet |  | |
| doxazosin oral - | 4 mg tablet |  | |
| doxazosin oral - | 8 mg tablet |  | |
| doxazosin oral - | 8 mg tablet |  | |
| doxazosin oral - | 8 mg tablet |  | |
| doxazosin oral - | 4 mg tablet |  | |
| doxazosin oral - | 1 mg tablet |  | |
| Cardura oral - | 1 mg tablet | | |
| Cardura oral - | 8 mg tablet | | |
| Cardura oral - | 4 mg tablet | | |
| Cardura oral - | 2 mg tablet | |
Copyright © 2010 First DataBank, Inc.
Patient Handout
doxazosin oral
DOXAZOSIN EXTENDED-RELEASE TABLET - ORAL
(dox-AZE-oh-sin)
COMMON BRAND NAME(S): Cardura XL
USES: Doxazosin is used in men to treat the symptoms of an enlarged prostate (benign prostatic hyperplasia-BPH). It does not shrink the prostate, but it works by relaxing the muscles in the prostate and part of the bladder. This helps to relieve symptoms of BPH such as difficulty in beginning the flow of urine, weak stream, and the need to urinate frequently or urgently (including during the middle of the night).Doxazosin belongs to a class of drugs known as alpha blockers.This medication should not be used to treat high blood pressure.
HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start taking doxazosin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth as directed by your doctor, usually once daily with breakfast.Doxazosin may cause a sudden drop in your blood pressure, which could lead to dizziness or fainting, usually within a few hours after you take it. This risk is higher when you first start taking this drug, after your doctor increases your dose, or if you restart treatment after you stop taking it. During these times, avoid situations where you may be injured if you faint.Swallow the tablets whole. Do not crush or chew the tablets. Doing so can release all of the drug at once, increasing the risk of side effects.The dosage is based on your medical condition and response to treatment.Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day. If you miss taking doxazosin for a few days, you may need to restart treatment at a lower dose and gradually increase your dose again. Consult your doctor for more details.If you are switching from another form of doxazosin to this extended-release form, be sure to follow your doctor's instructions closely.Tell your doctor if your condition does not improve or if it worsens.
SIDE EFFECTS: Dizziness, lightheadedness, or drowsiness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.An empty tablet shell may appear in your stool. This effect is harmless because your body has already absorbed the medication.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: sore throat that doesn't go away, fainting, shortness of breath, weakness, yellowing eyes/skin, dark urine, easy bleeding/bruising, fever.Get medical help right away if you have any very serious side effects, including: chest pain.Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking doxazosin, tell your doctor or pharmacist if you are allergic to it; or to other alpha blockers such as prazosin or terazosin; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: stomach/intestine problems (such as short bowel syndrome, chronic constipation, narrow gut, slow gut movement), heart disease (such as congestive heart failure, angina, heart attack in last 6 months), liver disease, low blood pressure, certain eye problems (cataracts, glaucoma).This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis). See also How to Use section.Before having surgery (including cataract/glaucoma eye surgery), tell your doctor or dentist if you are taking or have ever taken this medication, and about all the other products you use (including prescription drugs, nonprescription drugs, and herbal products).Older adults may be more sensitive to the side effects of this drug, especially dizziness and low blood pressure when getting up from a sitting or lying position. These side effects can increase the risk of falling.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.This medication passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: other alpha blocker drugs (such as prazosin, tamsulosin).If you are also taking a drug to treat erectile dysfunction-ED or pulmonary hypertension (such as sildenafil, tadalafil), your blood pressure may get too low which can lead to dizziness or fainting. Your doctor may need to adjust your medications to minimize this risk.Other medications can affect the removal of doxazosin from your body, which may affect how doxazosin works. Examples include azole antifungals (such as itraconazole, ketoconazole), macrolide antibiotics (such as clarithromycin), HIV protease inhibitors (such as lopinavir), ritonavir, among others.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe dizziness, fainting.
NOTES: Do not share this medication with others.Lab and/or medical tests (such as prostate exams, blood pressure) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up. See also How to Use section.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised December 2022. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
Adding plans allows you to compare formulary status to other drugs in the same class.
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.
