Cardura XL (Doxazosin) 4mg Pfizer

What Is Cardura XL 4mg?

Cardura XL 4mg is a prescription medication manufactured by Pfizer containing doxazosin, an alpha-1 blocker used to treat two common conditions in men: high blood pressure (hypertension) and the urinary symptoms associated with benign prostatic hyperplasia (BPH) — an enlarged prostate.

The "XL" (extended-release) formulation means the active ingredient is released slowly and steadily throughout the day, providing consistent, all-day relief with just one tablet taken daily.

What Is Cardura XL 4mg Used For?

For Benign Prostatic Hyperplasia (BPH) — Enlarged Prostate: If you experience difficulty urinating, a weak urine stream, frequent urges to urinate (especially at night), or a feeling that your bladder hasn't fully emptied, you may have BPH. Cardura XL 4mg helps relax the muscles in the prostate and bladder neck, making urination easier and more comfortable.

For High Blood Pressure (Hypertension): Cardura XL 4mg works by relaxing and widening the blood vessels, allowing blood to flow more freely. This helps lower blood pressure and reduces the workload on the heart.

How Does Cardura XL 4mg Work?

Doxazosin belongs to a class of drugs called alpha-1 adrenergic blockers. It selectively blocks alpha-1 receptors in the smooth muscle of blood vessels — causing them to relax and lower blood pressure — and in the prostate and bladder neck, relieving urinary obstruction caused by an enlarged prostate. The extended-release design ensures a stable drug level in your bloodstream throughout the day, reducing the risk of a sudden drop in blood pressure.

Dosage & How to Take It

The standard starting dose is 4mg once daily, though your doctor may adjust this. You can take it with or without food, but be consistent. Swallow the tablet whole — do not crush, chew, or split it, as this destroys the extended-release mechanism. It is best taken in the morning to minimise any dizziness during the day. Always follow your prescriber's instructions, and do not stop taking this medication suddenly without consulting your doctor.

Common Side Effects

Most people tolerate Cardura XL well. Possible side effects include dizziness or light-headedness (especially when standing up quickly), headache, fatigue or weakness, swollen ankles or feet, and a runny or blocked nose. Seek medical attention immediately if you experience a prolonged or painful erection, chest pain, fainting, or signs of a severe allergic reaction such as rash, swelling of the face, lips, or throat, or difficulty breathing.

Important Warnings & Precautions

Some patients experience a significant drop in blood pressure after the first dose — taking the first dose at night can reduce this risk. Dizziness may affect your ability to drive, so take caution until you know how this medicine affects you. Inform your surgeon or eye specialist if you are taking or have previously taken doxazosin, as it can affect procedures such as cataract surgery. It is not suitable for patients with a history of orthostatic hypotension, certain liver conditions, or those allergic to doxazosin or other quinazoline derivatives.