Cardura (Doxazosin)

(℞) Prescription Required

    Cardura (Doxazosin) Dosage and Side Effects

    CARDURA is used to treat benign prostatic hyperplasia (BPH) or Hypertension.

    Proper Use of this medication

    Follow your doctor's instructions very carefully about how to take CARDURA.

    For the treatment of Hypertension:

    Usual Adult Dose:

    Start with 1 mg once daily. Maximum recommended daily dose is 16 mg once daily.

    For the treatment of Benign Prostatic Hyperplasia:

    Usual Adult Dose:

    Start with 1 mg once daily. Maximum recommended daily dose is 8 mg once daily.

    Dose increase should be done gradually with caution due to consideration of possible dizziness/vertigo effect.

    Do not share CARDURA with anyone else; it was prescribed only for you.

    Notify your doctor about any illness which may develop during your treatment with CARDURA and about any new prescription or non-prescription medication you may take. If you require medical help for other reasons, inform the attending physician that you are taking CARDURA.

    You can take CARDURA either in the morning or at bedtime, with or without food. If you take CARDURA at bedtime but need to get up from bed to go to the bathroom, get up slowly and cautiously until you are sure how the medication affects you. It is important to get up slowly from a chair or bed at any time until you learn how you react to CARDURA. You should not drive or do any hazardous tasks until you are used to the effects of the medication. If you begin to feel dizzy, sit or lie down until you feel better.

    How long to take CARDURA:

    You should take CARDURA as long as your doctor thinks it is necessary.


    If you take too many tablets by accident, call a poison control center immediately.

    Missed dose:

    Talk with your doctor if you don't take it for a few days for some reason; you may then need to restart the medication at a 1 mg dose, increase your dose gradually and again be cautious about possible dizziness.

    Side Effects

    Side effects you could have while taking CARDURA include drowsiness, fatigue (tiredness), swelling of the feet, shortness of breath, weight gain, headache, and a decrease in your white blood cell count.

    You may also experience dry or reduced or other kinds of ejaculation disorders. This condition may be harmless but can lead to temporary infertility during the medication usage.

    Most side effects are mild. Discuss any unexpected effects you notice with your doctor.

    Serious Side Effects, How Often They Happen and What to Do About Them:

    Extremely rarely, CARDURA and similar medications have caused painful erection of the penis, sustained for hours and unrelieved by sexual intercourse or masturbation. This condition is serious, and if untreated it can be followed by permanent inability to have an erection. If you have a prolonged abnormal erection, call your doctor, or go to an emergency room as soon as possible.

    If you notice any of the following potentially serious side effects, please stop taking CARDURA and contact your doctor immediately:

    Warnings and Precautions

    BEFORE you use CARDURA talk to your doctor or pharmacist if:

    • you take phosphodiesterase (PDE-5)-inhibitor such as sildenafil, tadalafil or vardenafil, due to the risk of developing low blood pressure;

    • you take other medications, including those you can buy without prescription and herbal products, or if you drink alcohol;

    • you have or have had heart or blood vessel diseases;

    • you have heart problems;

    • you have or have had kidney and liver disease;

    • you have or have had stomach or intestinal problems;

    • you suffer from muscular dystrophy or other neuromuscular disorder;

    • you are pregnant or plan to get pregnant;

    • your are breastfeeding or plan to breastfeed.

    CARDURA can cause a sudden drop in blood pressure after the first dose or first few doses. You may feel dizzy, faint, or "light-headed", particularly after you get up from bed or from a chair. This is more likely to occur after you have taken the first few doses, but can occur at any time while you are taking the drug. It can also occur if you stop taking the drug and then restart treatment. If you feel very dizzy, faint or "light-headed" you should contact your doctor. Your doctor will discuss with you how often you need to visit and how often your blood pressure should be checked.

    In general, you should be cautious when using a phosphodiesterase (PDE-5) inhibitor such as sildenafil, tadalafil or vardenafil when taking CARDURA due to the risks of developing serious hypotension (low blood pressure).

    Your doctor has prescribed CARDURA for symptomatic BPH or High blood pressure and not for prostatic cancer. It is possible for men to have both BPH and prostate cancer at the same time. Doctors usually recommend that men be checked for prostate cancer once a year when they turn 50 (or 40 if a family member has had prostate cancer). These checks should continue while you are taking CARDURA. CARDURA is not a treatment for prostate cancer.

    About Prostate Specific Antigen (PSA)

    Your doctor may have done a blood test called PSA. Your doctor is aware that CARDURA does not affect PSA levels. You may want to ask your doctor more about this if you have a PSA test done.

    You should see an effect on your symptoms in 1 to 2 weeks. While taking CARDURA, you must have regular check-ups to evaluate your progress regarding your BPH and to monitor your blood pressure. Follow your doctor's advice about when to have these check-ups.

    If you drink alcohol the effects of the alcohol may be increased and prolonged. You should be aware of that and be more cautious with alcohol or you may wish to avoid alcohol altogether.

    If you’re seeing more than one doctor make sure that each one knows about all the medicines you are taking.

    Interactions with this medication

    The following list includes drugs that may interact with CARDURA:

    • drugs to treat erectile dysfunction (sildenafil, tadalafil, vardenafil)

    • drugs to treat hypertension, including diuretics (“water pills”) and other classes of medications

    • drugs to treat infections (clarithromycin, itraconazole, ketoconazole, telithromycin, voriconazole)

    • drugs to treat HIV infections (indinavir, nelfinavir, ritonavir, saquinavir)

    • drugs to treat depression (nefazodone)

    Talk to your doctor or pharmacist if you drink alcohol.

    Other related products

    The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

    Back to top
    Symantec Security Validated