What Does Flomax Do?

Published July 1st, 2020 by Bridget Reed
Fact Checked by
Chris Riley
Updated Date: Apr 9th, 2022

Benign prostatic hyperplasia affects approximately 70 percent of men over the age of 70 in the United States, making it one of the most common medical conditions affecting aging men.

Fortunately, there is no link between benign prostatic hyperplasia, also known as enlarged prostate or BPH, and prostate cancer, but the symptoms can still be frustrating, inconvenient, and embarrassing.  

Flomax is an FDA-approved medication for the treatment of the symptoms of benign prostatic hyperplasia, and while there are many benefits to the use of the medication, there are also some risks.

If you’ve been asking yourself What does Flomax do?” and wondering how it can help you, we have the complete guide to the medication. 

What Is Flomax?

Flomax, also sold under the generic name tamsulosin, belongs to a class of drugs called alpha-blockers.

Not to be confused with beta-blockers, which are used for blood pressure and cardiac issues, alpha-blockers block the action of a hormone called norepinephrine, which is responsible for causing the muscles in the walls of the veins and arteries to constrict.

Although alpha-blockers are sometimes used to treat high blood pressure, they are most often combined with other drugs, like diuretics, when used for this purpose.

flomax pill bottle

Flomax is an FDA-approved medication for the treatment of symptoms associated with benign prostatic hyperplasia and is not used for the treatment of blood pressure.  

What Is Flomax Used to Treat?

As the name suggests, Flomax is used for the treatment of symptoms associated with benign prostatic hyperplasia.

Although the development of BPH is commonly correlated to advancing age, it can also be impacted by lifestyle factors or caused by medical conditions like diabetes and heart disease.

BPH might be a common affliction, but that doesn’t make it any less frustrating and inconvenient, as it primarily impacts the ability to urinate properly. So, what is the prostate and what happens when it is enlarged?

The prostate is a gland that surrounds a portion of the urethra, a thin tube that carries urine and semen out of the penis.

When the prostate becomes enlarged, it squeezes or presses down on the urethra, diminishing the flow capacity. Prior to diagnosis with BPH, many men notice that they have difficulty beginning the flow of urination or suffer from a weak urine stream or dribbling urine.

While the urethra bears the brunt of the pressure from an enlarged prostate, other body parts are also affected. When the body has difficulty eliminating urine, the bladder begins to work harder in order to compensate.

Over time, this can cause the muscles of the bladder to weaken, making it even more difficult to empty your bladder.  Men with weak bladders may suffer from any or all of the following symptoms:

  • Waking up during the night to urinate
  • Frequent trips to the bathroom (eight or more times per day)
  • A sudden, urgent need to pee
  • Incomplete emptying (feeling like you have to urinate even after you just went)
  • Incontinence (lack of control over urination)

Although BPH can cause embarrassing and inconvenient symptoms, there are many different treatment options, including medications like Flomax. 

What Does Flomax Do?

Alpha-blockers like Flomax relax the muscles, veins, and arteries in the body by blocking the action of alpha1 receptors. Although many medications use the effects of alpha-blockers to treat heart problems, Flomax works specifically on alpha1 receptors in the prostate.

Flomax blocks the action of alpha1 receptors in and near the prostate, at the bladder neck, and at the top of the urethra. By preventing the receptors from absorbing alpha1, a hormone that causes the muscles to tighten, Flomax helps to increase the flow of urine and keep the enlargement of the prostate from squeezing the urethra.

Therefore, Flomax effectively treats the symptoms of BPH, but it does not treat the root cause of the condition, which is an enlarged prostate. Flomax does not reduce the size of the prostate, which will continue to grow over time. 

What Is the Cost of Flomax?

Flomax is available in both the brand name drug and in its generic form, called tamsulosin. In general, Flomax is considered a moderately priced drug.

A one month supply of 30 capsules (0.4 mg) costs between $7.17 and $9.50 for tamsulosin, while Flomax costs approximately $250 for a one month supply.

Although some men due take the brand name version of the medication for medical reasons, most men will be prescribed the generic version of the drug, which is widely available and more cost-effective.  

Although some people express concern over the quality of generic drugs, these concerns are unfounded; the FDA subjects generic forms of the medication to the same stringent testing as the brand name form of the drug. The generic medication uses the same active ingredient as the brand name form of the medication in the same amount but may use different inactive ingredients that affect the color, size, shape, or taste of the medication.

However, you will receive the same treatment when using a generic medication of the same form and strength as you would with a brand name medication.

Choosing a generic medication can help you save money on your prescription, but patients should also consider using a pharmacy discount card program like USA Rx. Pharmacy discount cards offer savings on all FDA-approved brand name and generic medications, including Flomax and tamsulosin. 

What Are the Benefits of Flomax?

Flomax is one of the most popular drugs for the treatment of BPH and has several benefits. Benefits of Flomax include:

  • Flomax effectively improves urine flow rates and other symptoms of BPH including hesitancy, intermittency, incomplete emptying, and weak urine streams.
  • Flomax is well tolerated by men with kidney or liver disease, who generally do not need to adjust their dosage of the medication. However, the use of Flomax in men with end-stage kidney or liver disease has not been studied.
  • Over 80 percent of patients who completed six years of treatment with Flomax reported a consistently positive response to the medication and a low incidence of orthostasis.

Are There Any Downsides Associated With Flomax?

In addition to the benefits associated with Flomax, the medication also has several downsides. The downsides of Flomax include:

  • When patients first start taking Flomax or after an increase in the dose, they may experience an unsafe drop in blood pressure when moving from sitting to standing. Vertigo and syncope, a temporary loss of consciousness, can also occur. Elderly men should be especially cautious when taking Flomax due to the increased risk of falls associated with the medication. 
  • Erections lasting longer than four hours, called priapism, have been known to occur in men taking Flomax. Priapism is a serious medical condition and should be attended to immediately. 
  • Flomax can cause an adverse reaction in people with a sulfa allergy.
  • Flomax can react with several different types of drugs, including CYP3A4 inhibitors like ketoconazole, CYP2D6 inhibitors like paroxetine, PDE5 inhibitors like Viagra, and blood thinners like warfarin.
  • Dizziness upon waking is common for men taking Flomax. Patients taking the medication should be careful when moving from a lying position to sitting or standing.
  • When combined with other factors, such as heart disease, dialysis, dehydration, a low-sodium diet, vomiting, diarrhea, or heavy sweating, Flomax can cause your blood pressure to become too low.

What Dose of Flomax Should I Take?

Flomax is sold in 0.4 mg capsules in both its generic and brand name forms. Most patients start on an initial dose of 0.4 mg taken orally once per day.

The maximum dose is 0.8 mg, or two capsules are taken once per day. The dosage of Flomax prescribed to you by your doctor will vary depending on the severity of your symptoms, your age, other health conditions, and other medications you may be taking.

Flomax is generally taken about 30 minutes after a meal and should be taken at the same time each day. 

What Are the Side Effects of Flomax?

Side effects associated with Flomax are categorized as either common or uncommon. Flomax is generally well tolerated by most men. Common side effects associated with Flomax that usually do not need medical attention include:

  • Sleep problems (insomnia)
  • Dizziness
  • Drowsiness
  • Weakness
  • Low blood pressure
  • Nausea
  • Diarrhea
  • Abnormal ejaculation
  • Decreased amount of semen
  • Blurred vision
  • Fever, chills, body aches, flu symptoms
  • Headache
  • Chest pain
  • Back pain
  • Tooth problems
  • Stuffy or runny nose, sinus pain, sore throat, cough
  • Decreased interest in sex

Most of the Flomax side effects listed above are mild and last for only a few days or weeks as your body adjusts to Flomax. If side effects persist or an allergic reaction develops, talk to your doctor.

Some side effects of Flomax do require medical attention. Check with your health care provider immediately if you experience any of the following uncommon but serious side effects while taking Flomax:

  • Lower back or side pain
  • A light-headed feeling/feeling like you might pass out
  • Priapism/painful erection lasting more than four hours
  • Cough or hoarseness
  • Painful or difficult urination
  • Chest pain
  • Severe skin reaction characterized by the following:
    • Red or purple skin rash that spreads
    • Blistering or peeling associated with the skin rash
    • Rash on the face or upper body
    • Fever 
    • Sore throat
    • Swelling in the face or tongue
    • Burning in the eyes
    • Painful skin

Is There a Link Between Flomax and Cognitive Decline?

Men’s prostates continue to grow in size as they age, so once men are diagnosed with BPH, they have the condition for life.

Therefore, men taking medication for the treatment of their symptoms often take medications like Flomax for many years. Recently, scientists have begun investigating the link between the continuous use of Flomax and other alpha-blockers with cognitive decline and dementia.

Anecdotal reports of a link between alpha-blockers and cognitive decline and dementia sparked the interest of researchers who decided to conduct studies to determine if a link could be conclusively determined.

A literature review of Medicare data from 2006 to 2012 showed an increased risk of dementia in patients over the age of 65 who were actively taking Flomax.

Patients taking Flomax experienced dementia at a rate of 31.3 per 1000 person-years compared to 25.9 per 1000 person-years in the control group of men who were not taking BPH medications. Other alpha-blockers and BPH medications, including doxazosin, terazosin, alfuzosin, dutasteride, and finasteride were also found to be linked to an increased risk of dementia and cognitive decline when compared to men who were not taking BPH medications.

The incidence of dementia was higher in patients taking Flomax than in patients taking any of the other medications, although each medication showed an elevated risk of cognitive decline. At this time, it is unknown why Flomax may contribute to cognitive decline or an increased risk of dementia. Some scientists suspect that Flomax causes symptoms of dementia to appear earlier in men who already had the condition but had not yet been diagnosed, but the exact cause is unknown.

More research is needed in order to conclusively determine the impact of Flomax on dementia rates and cognitive decline in elderly men. Patients should consider whether the benefits of taking Flomax to manage their BPH outweigh the risks and should get medical advice from their doctors before using Flomax.

Who Should Not Take Flomax?

Certain medical conditions may be exacerbated by the use of Flomax. People with the following medical conditions should speak to their doctor before taking Flomax:

  • Severe kidney disease
  • Severe liver disease
  • Allergy to sulfa drugs
  • Hypotension (low blood pressure)

People taking the following medications should inform their doctors prior to taking Flomax, as the medications may interact:

  • Antifungals, such as itraconazole and ketoconazole
  • Antihistamines, such as diphenhydramine
  • Beta-blockers such as atenolol or metoprolol
  • Cyclosporine
  • CYP3A4 or CYP2D inducers or inhibitors
  • HIV medications such as ritonavir
  • Antibiotics such as clarithromycin, erythromycin, or doxycycline
  • Antidepressants, such as fluoxetine, paroxetine, St John’s Wort, monoamine oxidase inhibitors, and tricyclic antidepressants (such as amitriptyline, imipramine, and nortriptyline)
  • Imatinib
  • Other alpha-blockers such as prazosin or terazosin
  • Some medications used to treat mental illness, such as clozapine or thioridazine
  • Some heart medications, such as amiodarone, clonidine, digoxin, diltiazem, propafenone, quinidine, and verapamil
  • NSAIDs, such as diclofenac, ibuprofen, and indomethacin, may decrease the blood pressure-lowering capabilities of Flomax.

References and Sources:

Flomax - Info

Published July 1st, 2020 by Bridget Reed
Fact Checked by
Chris Riley
Updated Date: Apr 9th, 2022

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