Doxazosin STADA
Alpha-1 adrenergic antagonist for hypertension and benign prostatic hyperplasia (BPH)
Doxazosin STADA is a prescription medication containing doxazosin mesilate, an alpha-1 adrenergic antagonist. It is used to treat high blood pressure (hypertension) and to relieve urinary symptoms caused by benign prostatic hyperplasia (BPH). The extended-release formulation provides controlled drug delivery over 24 hours, typically requiring only one tablet daily.
Quick Facts
Key Takeaways
- Doxazosin STADA is prescribed for both high blood pressure and benign prostatic hyperplasia (BPH), making it particularly useful for men who have both conditions.
- The extended-release formulation should be swallowed whole — never crushed, chewed, or split — to ensure proper controlled release over 24 hours.
- Orthostatic hypotension (dizziness upon standing) is a known risk, especially at the start of treatment. Rise slowly from sitting or lying positions.
- Inform your eye surgeon before cataract surgery if you take or have ever taken doxazosin, due to the risk of Intraoperative Floppy Iris Syndrome (IFIS).
- Use caution when combining with PDE5 inhibitors (sildenafil, tadalafil, vardenafil), as both lower blood pressure and the combined effect may cause dangerous drops.
What Is Doxazosin STADA and What Is It Used For?
Quick Answer: Doxazosin STADA contains doxazosin mesilate, an alpha-1 adrenergic antagonist that relaxes blood vessels and prostatic smooth muscle. It is prescribed to lower high blood pressure and to relieve urinary symptoms associated with an enlarged prostate (BPH).
Doxazosin STADA belongs to a class of medications known as alpha-1 adrenergic receptor antagonists (alpha-1 blockers). The active ingredient, doxazosin, works by selectively blocking alpha-1 adrenergic receptors found on the smooth muscle of blood vessels and the prostate gland. By blocking these receptors, the medication causes relaxation of vascular smooth muscle, which widens blood vessels and makes it easier for the heart to pump blood through them. This mechanism effectively lowers blood pressure and reduces the risk of cardiovascular complications associated with hypertension, including heart disease, stroke, and kidney damage.
For patients with benign prostatic hyperplasia (BPH), doxazosin provides relief by relaxing the smooth muscle around the bladder neck and the prostate gland. BPH is a common condition in older men where the prostate gland becomes enlarged, compressing the urethra and making it difficult to urinate. Symptoms include a weak urine stream, frequent urination (especially at night), difficulty starting urination, and a feeling of incomplete bladder emptying. By relaxing these muscles, Doxazosin STADA improves urine flow and reduces the bothersome lower urinary tract symptoms associated with BPH.
The extended-release formulation of Doxazosin STADA is specifically designed to deliver the active ingredient gradually over a 24-hour period. This controlled-release mechanism provides more consistent plasma drug levels throughout the day, potentially reducing the peak-related side effects (such as dizziness and orthostatic hypotension) that can occur with immediate-release formulations. Clinical studies, including the landmark ALLHAT trial published in JAMA, have established doxazosin as an effective antihypertensive agent, though it is typically not recommended as a first-line monotherapy for hypertension.
One of the clinical advantages of doxazosin is its dual utility: men who suffer from both hypertension and BPH can benefit from a single medication that addresses both conditions simultaneously. According to guidelines from the European Association of Urology (EAU) and the American Urological Association (AUA), alpha-1 blockers are considered first-line pharmacological therapy for moderate-to-severe BPH symptoms. The blood pressure-lowering effect is also beneficial, as many men with BPH are in an age group where hypertension is prevalent.
Doxazosin STADA is a prescription-only medication. Do not start, stop, or change the dose without consulting your healthcare provider. Your doctor will determine whether this medication is appropriate for your condition and will monitor your response to treatment.
What Should You Know Before Taking Doxazosin STADA?
Quick Answer: Do not take Doxazosin STADA if you are allergic to doxazosin or quinazoline derivatives, have low blood pressure, or certain urinary or gastrointestinal obstructions. Use caution if you have liver disease, heart failure, or are taking PDE5 inhibitors for erectile dysfunction.
Contraindications
Doxazosin STADA must not be used in the following situations, as it could cause serious harm:
- Allergy to doxazosin or quinazoline derivatives: If you are allergic to doxazosin, to other quinazoline-based drugs such as prazosin or terazosin, or to any of the inactive ingredients in Doxazosin STADA, you must not take this medication. Signs of an allergic reaction include skin rash, itching, swelling of the face or throat, and difficulty breathing.
- Hypotension: If you have abnormally low blood pressure or a history of orthostatic hypotension (blood pressure drops causing dizziness, lightheadedness, or fainting when standing up), Doxazosin STADA should not be used.
- BPH with urinary tract complications: If you have BPH along with upper urinary tract obstruction, chronic urinary tract infection, or bladder stones, this medication is not appropriate for you.
- Gastrointestinal obstruction: If you have or have had any form of narrowing or obstruction in the gastrointestinal tract, do not take Doxazosin STADA, as the extended-release tablet shell passes through the digestive system intact.
- Overflow incontinence or anuria: If you have loss of bladder control due to overflow incontinence, no urine production (anuria), or progressively worsening kidney function, this medication is contraindicated.
- Breastfeeding: Doxazosin STADA must not be used while breastfeeding.
Warnings and Precautions
Several important warnings apply when taking Doxazosin STADA. Orthostatic hypotension — a sudden drop in blood pressure when changing position from lying or sitting to standing — is one of the most significant concerns, particularly during the initial phase of treatment. This can manifest as dizziness, weakness, lightheadedness, or even fainting episodes. These symptoms are most likely to occur when you first start taking the medication, when your dose is increased, or when you resume treatment after a break. To minimize this risk, stand up slowly and avoid abrupt changes in posture. If you experience these symptoms, sit or lie down immediately until they pass.
Patients with liver disease should exercise particular caution, as doxazosin is extensively metabolized in the liver. Your doctor may need to adjust your dose or monitor your liver function more frequently. Similarly, patients with a history of heart failure or other acute cardiac conditions should discuss the risks and benefits of doxazosin therapy with their physician, as some studies have raised concerns about cardiovascular outcomes with alpha-blocker use in certain patient populations.
If you notice what appears to be a tablet remnant in your stool, this is normal and not a cause for concern. The Doxazosin STADA extended-release tablet has a non-absorbable shell that is designed to release the medication gradually; the empty shell is then expelled naturally.
If you are scheduled for cataract (lens opacity) surgery, inform your ophthalmologist that you are using or have previously used Doxazosin STADA. Alpha-1 blockers can cause a condition called Intraoperative Floppy Iris Syndrome (IFIS), which can lead to complications during the surgical procedure. If your surgeon is aware of your medication history, they can take appropriate precautions to manage this risk.
Children and Adolescents
Doxazosin STADA is not recommended for use in children or adolescents under 18 years of age. The safety and efficacy of doxazosin have not been established in the pediatric population, and there is insufficient clinical evidence to support its use in this age group. If you have concerns about blood pressure management in a child or adolescent, consult a pediatric specialist.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to have a baby, consult your doctor before taking Doxazosin STADA. Experience with the use of doxazosin during pregnancy is limited, and the potential risks to the developing fetus have not been fully evaluated. Your doctor will weigh the potential benefits against the possible risks before deciding whether treatment with doxazosin is appropriate during pregnancy.
Doxazosin STADA should not be used during breastfeeding. It is not known whether doxazosin passes into breast milk, and therefore nursing mothers should not take this medication. If treatment with doxazosin is necessary, your doctor will advise you to stop breastfeeding.
Driving and Operating Machinery
Doxazosin STADA can cause drowsiness, dizziness, and lightheadedness, which may impair your ability to drive or operate heavy machinery safely. These effects are particularly likely when you first start treatment, when your dose is increased, or when you resume the medication after an interruption. Do not drive or operate machinery if you are experiencing dizziness or feel faint. You are responsible for assessing your own fitness to perform these activities.
Sodium Content
Doxazosin STADA contains less than 1 mmol (23 mg) of sodium per tablet, meaning it is essentially sodium-free. This is relevant for patients who are following a controlled sodium diet.
How Does Doxazosin STADA Interact with Other Drugs?
Quick Answer: Doxazosin STADA can interact with other blood pressure-lowering medications, PDE5 inhibitors (such as sildenafil), and NSAIDs. These interactions can either increase the risk of low blood pressure or reduce the effectiveness of doxazosin.
Drug interactions are an important consideration when taking Doxazosin STADA. Because doxazosin lowers blood pressure, combining it with other medications that also reduce blood pressure can lead to an additive hypotensive effect, potentially causing dangerously low blood pressure. Always inform your healthcare provider about all medications you are taking, including prescription drugs, over-the-counter medicines, and herbal supplements.
PDE5 Inhibitors (Erectile Dysfunction Medications)
One of the most clinically significant interactions involves PDE5 inhibitors used to treat erectile dysfunction, including sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra). Both doxazosin and PDE5 inhibitors have vasodilatory (blood vessel-widening) effects, and using them together can result in a substantial drop in blood pressure. Symptoms may include severe dizziness, lightheadedness, or fainting. To minimize this risk, you should be stabilized on a regular, fixed daily dose of Doxazosin STADA before starting a PDE5 inhibitor. Always consult your doctor before combining these medications.
Other Antihypertensive Agents
Combining doxazosin with other blood pressure-lowering medications — such as ACE inhibitors, angiotensin II receptor blockers (ARBs), beta-blockers, calcium channel blockers, or diuretics — can lead to an enhanced hypotensive effect. While these combinations are sometimes intentionally used under medical supervision to achieve better blood pressure control, the additive effect means a greater risk of orthostatic hypotension and its associated symptoms.
| Drug / Drug Class | Interaction Type | Effect | Clinical Advice |
|---|---|---|---|
| PDE5 inhibitors (sildenafil, tadalafil, vardenafil) | Major | Additive blood pressure lowering; risk of symptomatic hypotension | Stabilize on doxazosin first; start PDE5 inhibitor at lowest dose |
| Other antihypertensives (ACE inhibitors, ARBs, beta-blockers, CCBs, diuretics) | Moderate | Enhanced blood pressure reduction; increased orthostatic hypotension risk | Monitor blood pressure closely; dose adjustment may be needed |
| NSAIDs (ibuprofen, naproxen, diclofenac) | Moderate | May reduce the blood pressure-lowering effect of doxazosin | Monitor blood pressure; consider alternative pain relief |
| Other alpha-blockers (tamsulosin, prazosin, terazosin) | Major | Excessive alpha-blockade; severe hypotension risk | Avoid concomitant use; do not combine alpha-blockers |
| General anaesthetics | Moderate | Increased risk of hypotension during surgery | Inform your anaesthetist about doxazosin use before surgery |
Food and Drink
Doxazosin STADA can be taken with or without food. The extended-release formulation is designed to provide consistent drug release regardless of meal timing. However, alcohol consumption should be approached with caution as it can exacerbate the blood pressure-lowering effect of doxazosin, increasing the risk of dizziness and orthostatic hypotension.
What Is the Correct Dosage of Doxazosin STADA?
Quick Answer: The usual dose of Doxazosin STADA is one 4 mg extended-release tablet once daily. Your doctor may increase the dose to a maximum of 8 mg (two tablets) daily. The tablet must be swallowed whole and can be taken at any time of day.
Always take Doxazosin STADA exactly as your doctor has instructed. If you are unsure about anything, consult your doctor or pharmacist. The dosage for treating high blood pressure is the same as for treating symptoms of BPH. This makes dosing straightforward, particularly for men who have both conditions.
Adults
Standard Dosing
Starting dose: One tablet (4 mg) once daily.
Maximum dose: Two tablets (8 mg) once daily, if your doctor determines that a higher dose is needed for adequate symptom control.
Administration: Swallow the tablet whole with a generous amount of liquid. Do not crush, chew, or split the tablet, as this would compromise the extended-release mechanism and potentially lead to excessive drug release.
Doxazosin STADA is specifically formulated to release the active ingredient evenly throughout the day. You can take the tablet at any time of day, with or without food. Choose a time that is convenient for you and take the tablet at the same time each day to maintain consistent blood levels. Some patients prefer taking it in the evening to reduce the impact of any initial dizziness, although this is a matter of personal preference and should be discussed with your doctor.
| Patient Group | Initial Dose | Maximum Dose | Notes |
|---|---|---|---|
| Adults (hypertension) | 4 mg once daily | 8 mg once daily | Blood pressure should be monitored regularly |
| Adults (BPH) | 4 mg once daily | 8 mg once daily | Symptom improvement typically occurs within 1–2 weeks |
| Elderly patients | 4 mg once daily | 8 mg once daily | Extra caution due to increased risk of orthostatic hypotension |
| Hepatic impairment | Physician discretion | Physician discretion | Reduced dose may be needed; contraindicated in severe hepatic impairment |
| Children (<18 years) | Not recommended | Not recommended | Safety and efficacy not established |
Elderly Patients
Elderly patients are at greater risk of orthostatic hypotension and falls. While no specific dose adjustment is required by age alone, your doctor will consider your overall health, other medications you take, and your risk of falls when prescribing Doxazosin STADA. Extra care should be taken when standing up, particularly during the initial treatment period or after dose adjustments.
Missed Dose
If you forget to take a dose of Doxazosin STADA, do not worry. Simply take your next dose at the usual time the following day. Do not take a double dose to compensate for the one you missed. Taking two doses at once increases the risk of a significant blood pressure drop and associated symptoms.
Overdose
If you take too many Doxazosin STADA tablets, or if a child accidentally ingests the medication, contact your doctor, go to the nearest emergency department, or call your local poison control center immediately. The most likely symptoms of an overdose are feeling faint or dizzy due to a significant drop in blood pressure. If this occurs, lie down on your back with your feet elevated above heart level until emergency help arrives.
Stopping Treatment
Continue taking Doxazosin STADA until your doctor tells you to stop. Do not discontinue the medication on your own, even if you feel your blood pressure is well controlled or your BPH symptoms have improved. Stopping suddenly without medical guidance could lead to a rebound increase in blood pressure or a return of urinary symptoms.
What Are the Side Effects of Doxazosin STADA?
Quick Answer: Common side effects include dizziness, headache, drowsiness, fatigue, and low blood pressure (especially when standing up). Uncommon effects include palpitations, nausea, and sleep disturbances. Rare but serious effects include fainting, abnormal heart rhythms, and liver problems.
Like all medications, Doxazosin STADA can cause side effects, although not everyone will experience them. The side effects listed below are categorized by how frequently they occur based on clinical data and post-marketing surveillance. Most side effects are mild to moderate and tend to diminish as your body adjusts to the medication. However, some side effects can be serious and require prompt medical attention.
Common
May affect up to 1 in 10 people
- Respiratory tract infection
- Dizziness, headache, drowsiness
- Unsteadiness or balance problems
- Palpitations (sensation of rapid or irregular heartbeat), increased heart rate
- Low blood pressure, orthostatic hypotension (blood pressure drop upon standing)
- Bronchial inflammation, cough, shortness of breath, nasal congestion or runny nose
- Abdominal pain, indigestion, dry mouth, nausea
- Itching
- Back pain, muscle pain
- Urinary tract infection, cystitis (bladder inflammation), urinary incontinence
- General weakness, chest pain, flu-like symptoms, swelling (oedema)
Uncommon
May affect up to 1 in 100 people
- Allergic drug reactions
- Loss of appetite, gout, increased appetite
- Anxiety, emotional instability, insomnia
- Stroke, decreased sensation, fainting, tremor, tinnitus (ringing in the ears)
- Chest pain (angina), heart attack, nosebleed
- Constipation, diarrhoea, bloating, vomiting, gastroenteritis
- Abnormal liver function tests
- Skin rash
- Joint pain
- Painful or difficult urination, blood in urine, increased urination frequency
- Erectile dysfunction (impotence)
- Weight gain, facial swelling
Very Rare
May affect up to 1 in 10,000 people
- Decreased platelet count (thrombocytopenia)
- Decreased red and white blood cell counts
- Positional dizziness
- Restlessness, agitation
- Tingling or prickling sensations (paraesthesia)
- Blurred vision
- Slow heart rate (bradycardia), irregular heartbeat (arrhythmia)
- Flushing (hot flushes)
- Bronchospasm (narrowing of the airways)
- Cholestasis (blocked bile flow), hepatitis (liver inflammation), jaundice
- Hair loss (alopecia), purpura (skin bruising), urticaria (hives)
- Muscle cramps, muscle weakness
- Urinary disturbances, increased nighttime urination, increased urine volume
- Gynecomastia (temporary breast enlargement in men)
- Priapism (painful, prolonged erection) — seek immediate medical attention
- Fatigue, malaise
Frequency Not Known
Cannot be estimated from available data
- Intraoperative Floppy Iris Syndrome (IFIS) — a complication affecting the iris muscle during cataract surgery
- Taste disturbances (dysgeusia)
- Retrograde ejaculation (ejaculation into the bladder)
Rare cases of syncope (fainting) associated with postural hypotension have been observed, especially during the initial phase of treatment. If you experience fainting or near-fainting episodes, contact your doctor promptly. These symptoms can usually be managed by adjusting the dose or modifying how quickly you change positions.
It is important to report suspected side effects after a medicine has been authorized. This allows ongoing monitoring of the medicine's benefit-risk balance. You can report side effects to your national medicines regulatory authority or through your healthcare provider. In the US, contact the FDA MedWatch program. In the EU, contact your national competent authority or the EMA.
How Should You Store Doxazosin STADA?
Quick Answer: Store Doxazosin STADA at room temperature, out of reach of children. No special storage conditions are required. Check the expiry date on the packaging and do not use after it has passed.
Keep Doxazosin STADA out of the sight and reach of children. Store the medication in its original packaging to protect it from light and moisture. This medication does not require any special storage conditions — standard room temperature storage is sufficient. Avoid exposing the tablets to excessive heat, direct sunlight, or damp environments such as bathrooms.
Do not use Doxazosin STADA after the expiry date printed on the carton and blister packaging after “EXP.” The expiry date refers to the last day of the stated month. If your tablets have passed their expiry date or you no longer need them, do not dispose of them via household waste or by flushing them down the toilet. Return unused or expired medications to your pharmacy for safe disposal, which helps protect the environment.
What Does Doxazosin STADA Contain?
Quick Answer: Each Doxazosin STADA extended-release tablet contains 4.85 mg doxazosin mesilate, equivalent to 4 mg doxazosin. The tablets are white, round, biconvex, and imprinted with “DL” on one side.
Active Substance
The active substance is doxazosin (as mesilate). Each extended-release tablet contains 4.85 mg doxazosin mesilate, which is equivalent to 4 mg of doxazosin base. The mesilate salt form is used to enhance stability and bioavailability of the active compound.
Inactive Ingredients (Excipients)
The tablet contains a carefully selected combination of excipients that enable the extended-release mechanism:
- Tablet core: Macrogol, microcrystalline cellulose, povidone K 29-32, butylhydroxytoluene (E321), alpha-tocopherol, colloidal anhydrous silica, sodium stearyl fumarate
- Coating: Methacrylic acid-ethyl acrylate copolymer (1:1) dispersion 30%, colloidal hydrated silica, macrogol 1300-1600, titanium dioxide (E171)
Appearance and Packaging
Doxazosin STADA tablets are white, round, and biconvex (slightly curved on both sides), with “DL” imprinted on one side. The tablets are supplied in PVC/PVDC/aluminium blister packs. Available pack sizes vary by market and may include 5, 10, 14, 20, 28, 30, 40, 50, 56, 60, 80, 84, 90, 98, 100, 150, 196, 200, 250, 300, 400, 500, and 1,000 tablets. Not all pack sizes may be marketed in your country.
Marketing Authorization Holder and Manufacturer
Marketing authorization holder: STADA Arzneimittel AG, Stadastrasse 2-18, 61118 Bad Vilbel, Germany.
Manufacturer: STADA Production Ireland Ltd., Waterford Road, Clonmel, Co. Tipperary, Ireland.
Frequently Asked Questions About Doxazosin STADA
Doxazosin STADA is used to treat two conditions: high blood pressure (hypertension) and urinary symptoms caused by an enlarged prostate (benign prostatic hyperplasia, or BPH). It works by relaxing blood vessels to lower blood pressure, and by relaxing the muscles around the bladder neck and prostate to improve urine flow. Many men with both conditions benefit from this dual action.
Yes, dizziness is one of the most common side effects of Doxazosin STADA, particularly when starting the medication, increasing the dose, or restarting after a break. This is usually caused by orthostatic hypotension — a temporary drop in blood pressure when you stand up. To reduce this risk, stand up slowly, especially first thing in the morning or after sitting for a long period. If dizziness is severe or persistent, consult your doctor.
Caution is required when combining Doxazosin STADA with PDE5 inhibitors such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra). Both types of medication lower blood pressure, and using them together can lead to symptomatic hypotension (dangerously low blood pressure). You should be on a stable daily dose of doxazosin before starting an erectile dysfunction medication, and always consult your doctor beforehand.
Absolutely. You must inform your eye surgeon before cataract surgery if you are currently taking or have ever taken Doxazosin STADA or any other alpha-blocker. These medications can cause a condition called Intraoperative Floppy Iris Syndrome (IFIS), which can make the surgical procedure more challenging. If your surgeon knows about your medication history beforehand, they can use modified surgical techniques to manage the risk effectively.
No, you must never crush, chew, or split Doxazosin STADA extended-release tablets. These tablets are specially designed with a controlled-release mechanism that delivers the medication gradually over 24 hours. Destroying the tablet structure would release all the doxazosin at once, which could lead to an excessive drop in blood pressure and increase the risk of serious side effects. Always swallow the tablet whole with a generous amount of water.
If you miss a dose, simply take your next dose at the usual scheduled time the following day. Do not take a double dose to compensate for the missed one, as this could cause a significant drop in blood pressure. Try to take Doxazosin STADA at the same time each day to help you remember. If you frequently forget doses, consider setting a daily reminder alarm.
References
- European Medicines Agency (EMA). Doxazosin — Summary of Product Characteristics. www.ema.europa.eu
- ALLHAT Officers and Coordinators. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs diuretic. JAMA. 2002;288(23):2981-2997. doi:10.1001/jama.288.23.2981
- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. Journal of the American College of Cardiology. 2018;71(19):e127-e248.
- Gravas S, Cornu JN, Gacci M, et al. EAU Guidelines on Management of Non-Neurogenic Male Lower Urinary Tract Symptoms (LUTS), incl. Benign Prostatic Obstruction (BPO). European Association of Urology, 2024. uroweb.org
- British National Formulary (BNF). Doxazosin. National Institute for Health and Care Excellence (NICE). bnf.nice.org.uk
- World Health Organization (WHO). Model List of Essential Medicines — 23rd List, 2023. www.who.int
- U.S. Food and Drug Administration (FDA). Doxazosin Mesylate — Prescribing Information. www.accessdata.fda.gov
- Chang DF, Campbell JR. Intraoperative floppy iris syndrome associated with tamsulosin. J Cataract Refract Surg. 2005;31(4):664-673. doi:10.1016/j.jcrs.2005.02.027
Medical Editorial Team
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All content is independently produced with no pharmaceutical company involvement. Our editorial process follows international evidence-based medicine standards. Last reviewed: .