Cardura XL

DRUG DESCRIPTION

CARDURA® XL (doxazosin mesylate extended release tablets) contains doxazosin mesylate which is a quinazoline compound with the chemical name 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(1,4benzodioxan-2-ylcarbonyl) piperazine methanesulfonate. The empirical formula for doxazosin mesylate is C23H25N5O5 •CH4O3S and the molecular weight is 547.6. It has the following structure:

CARDURA XL (doxazosin mesylate) Structural Formula Illustration

CARDURA XL (doxazosin mesylate extended release tablets) is an extended release tablet for oral use and is designed to deliver 4 or 8 mg of doxazosin as the free base. Each 4 and 8 mg tablet contains 5.1 and 10.2 mg doxazosin mesylate (includes a 5% overage) to provide 4 and 8 mg doxazosin as a free base, respectively. The inactive ingredients for CARDURA XL are: polyethylene oxide, sodium chloride, hypromellose, red ferric oxide, titanium dioxide, magnesium stearate, cellulose acetate, Macrogol®, pharmaceutical glaze, and black iron oxide.

CARDURA XL (doxazosin mesylate extended release tablets) System Components and Performance

CARDURA XL (doxazosin mesylate extended release tablets) is similar in appearance to a conventional tablet. It consists, however, of an osmotically active drug core surrounded by a semipermeable membrane. The core itself is divided into two layers: an “active” layer containing the drug, and a “push” layer containing pharmacologically inert (but osmotically active) components. The membrane surrounding the tablet is permeable to water but not to drug or osmotic excipients. As water from the gastrointestinal tract enters the tablet, pressure increases in the osmotic layer and “pushes” against the drug layer, resulting in the release of drug through a small, laser-drilled orifice in the membrane on the drug side of the tablet.

CARDURA XL (doxazosin mesylate extended release tablets) utilizes GITS (Gastrointestinal Therapeutic System) which is designed to provide a controlled rate of delivery of doxazosin into the gastrointestinal lumen which is independent of pH or gastrointestinal (GI) motility. The function of CARDURA XL (doxazosin mesylate extended release tablets) depends upon the existence of an osmotic gradient between the contents of the bi-layer core and fluid in the GI tract. Drug delivery is essentially constant as long as the osmotic gradient remains constant, and then gradually falls to zero. The biologically inert components of the tablet remain intact during GI transit and are eliminated in the feces as an insoluble shell.

What are the precautions when taking doxazosin mesylate extended release tablets (Cardura XL)?

Before taking doxazosin, tell your doctor or pharmacist if you are allergic to it; or to other alpha blockers such as prazosin and 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: prostate cancer, stomach/intestine problems (e.g., short bowel syndrome, chronic constipation, narrowing gut, slow gut movement), heart disease (e.g., congestive heart failure, angina, heart attack in last 6 months), liver disease.

To minimize dizziness and lightheadedness, get up slowly when rising from a sitting or lying position, especially when you first...

Read All Potential Precautions of Cardura XL »


Cardura XL Consumer (continued)

SIDE EFFECTS: Dizziness, headache, drowsiness, stomach upset/pain, or decreased sexual ability/interest may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

An empty tablet shell may appear in your stool. This is harmless since your body has already absorbed the medication.

Remember that your doctor has prescribed this medication because he or she 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 immediately if any of these unlikely but serious side effects occur: fainting, shortness of breath, weakness.

Tell your doctor immediately if any of these rare but very serious side effects occur: yellowing eyes/skin, dark urine, easy bleeding/bruising, fever, persistent sore throat.

Seek immediate medical attention if any of these rare but very serious side effects occur: vision changes, chest pain, jaw/left arm pain, weakness on one side of the body, slurred speech, confusion.

In the unlikely event you have a painful or prolonged erection lasting 4 or more hours, stop using this drug and seek immediate medical attention, or permanent problems could occur.

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: 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.

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 and 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: prostate cancer, stomach/intestine problems (e.g., short bowel syndrome, chronic constipation, narrowing gut, slow gut movement), heart disease (e.g., congestive heart failure, angina, heart attack in last 6 months), liver disease.

To minimize dizziness and lightheadedness, get up slowly when rising from a sitting or lying position, especially when you first start taking this drug or if your doctor changes your dose. Also, when you first start taking this drug, avoid situations where you may be injured if you faint.

This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

The elderly may be at a greater risk for dizziness and low blood pressure while using this drug.

Before having surgery (including cataract eye surgery), tell your doctor or dentist that you are taking this medication.

This medication should not be used in women.



Related Drugs Index: