Flomax Side Effects After Stopping

Some conditions can cause a simple natural occurrence like urination to become problematic.

Frequent urination during the day or at night, the urgent need to urinate, difficulty starting urination, dribbling at the end of urination, inability to completely empty the bladder, and a weak urine stream or a stream that stops intermittently are symptoms of a condition known as Benign Prostatic Hyperplasia (BPH).

If you experience any of the above symptoms, you should see a doctor immediately. One of the medications used to manage this condition is Flomax. This article discusses Flomax; its use, side effects and what happens when it is discontinued.

Flomax– Dosage And How It Works

Flomax is recommended for BPH

Flomax is a brand name for the generic alpha-blocker Tamsulosin. It is an oral capsule that can be used alone or in conjunction with a drug from another class of drugs used in BPH management. It is administered at a dose of 0.4mg or 0.8mg once daily.

Like other alpha receptor blockers, Flomax acts by blocking the alpha-1 receptors found on the muscles of the prostate gland, urethra, and bladder neck. By doing this, it causes the muscles around these areas to relax, thus preventing them from enlargement, and improving the flow of urine.


Side Effects Of Stopping Flomax

side effects

Discontinuation of Flomax may result in some unwanted effects. However, weaning off Flomax by the gradual reduction in dose can reduce the intensity or even likelihood of occurrence of these effects.

1. Return Of BPH Symptoms

Discontinuation of Flomax may result in the return of BPH symptoms, such as urinary urgency, incomplete bladder emptying, and a weak urine stream. If these symptoms persist, they may predispose to chronic renal failure, recurrent urinary tract infections, and even bladder stones.

In some cases, it might be advisable to change medications or switch to an alternative therapy like the minimally invasive surgery or radiation rather than outright discontinuation of Flomax.

2. Cardiovascular Side Effects

A change in dose or discontinuation of Flomax can cause changes in blood pressure, which can lead to dizziness or even fainting in some cases. It is very important to closely monitor your blood pressure anytime the dose of the drug is changed.

If you are taking an antihypertensive (a drug taken to lower the blood pressure), it may be necessary to adjust the dose of the antihypertensive as you gradually lower the dose of Flomax. This underscores the importance of ensuring that your doctor is aware of all the medications you are taking.

It is a good idea to stay away from heavy machines and high-risk tasks such as driving until you are sure it is safe to do so.

In many cases, the effects of Flomax discontinuation lasted for weeks after which people reported no effects and normal urination. If you experience these effects for longer than 4 weeks, please inform your doctor.

Why Do People Stop Using Flomax?


In many cases, people discontinue the use of Flomax for reasons such as listed below.

1. When Preparing For Cataract Surgery

As mentioned above, Flomax use has been associated with Intraoperative floppy iris syndrome, which has potentially fatal consequences during cataract surgery and is a serious concern for ophthalmologists (doctors who specialize in eye and vision care). The ophthalmologist may advise that Flomax is discontinued for some time before the surgery, to avoid this complication.

2. Relief From BPH Symptoms

Some people choose to discontinue Flomax when they have had effective relief from the BPH symptoms. A study suggests that continual use of Flomax may not be necessary for urinary symptom relief in patients who feel symptom improvement after initial treatment with Flomax. It is strongly advised that you consult your doctor before discontinuing the use of Flomax.


3. Potential Drug Interactions

medication interactions

People sometimes discontinue the use of Flomax because of its interaction with other medications they are using. Flomax is known to interact with the following drugs:

  • Antibiotic medications like chloramphenicol, Biaxin (clarithromycin) and Ketek (telithromycin), Vibramycin (doxycycline); Erythrocin (erythromycin); Vigamox (moxifloxacin)
  • Antifungal medications like Sporanox (itraconazole), Noxafil (posaconazole), and Nizoral (ketoconazole)
  • Antiviral medications like Kaletra (lopinavir/ritonavir) and Norvir (ritonavir), and Victrelis (Boceprevir)
  • Anticancer medications like Gleevec (imatinib)
  • Antacids like Tagamet (cimetidine), Zantac (ranitidine) and Pepcid (famotidine).
  • Other alpha-blocker medications for prostate conditions like Minipress (prazosin), Rapaflo (silodosin), Hytrin (terazosin)
  • Antidepressants belonging to selective serotonin reuptake inhibitors (SSRIs) class, such as Zoloft (sertraline) or Prozac (fluoxetine)
  • Antidepressants belonging to tricyclic antidepressants (TCAs) class such as Paxil (paroxetine), Anafranil (clomipramine), and Norpramin (desipramine)

Always check with your doctor or pharmacist before taking any medication while you are taking Flomax.

4. Inability To Tolerate Side Effects

Some people are just unable to tolerate the side effects of Flomax, regardless of the fact that they have benefited from effective relief of their BPH symptoms, hence they discontinue its use.

Whatever your reason, if you choose to discontinue the use of Flomax, it is advisable not to stop abruptly. Discuss your intention with your doctor who would work with you to gradually decrease the dose over a period of time in order to avoid the return of BPH symptoms or heart and blood pressure complications.

General Side Effects Of Flomax

Usually, upon commencement of the medication or during the course of therapy, you may experience some of these side effects;

  1. Orthostatic Hypotension, a sudden drop in blood pressure upon standing. It is usually associated with symptoms such as dizziness, lightheadedness, and fainting. This can be aggravated in people who are also taking blood pressure-lowering drugs.
  2. You may also experience a headache with Flomax
  3. Ejaculation problems may also occur, which may present as any of the following
    1. Decreased ease of ejaculation
    2. Inability to ejaculate
    3. Ejaculation of semen into the bladder instead of out of the body
  4. Priapism refers to the painful, continuous erection of the penis, lasting more than 4 hours without sexual stimulation, does not go away and is not relieved by sex. This side effect is not common but there have been documented case reports. Priapism is a medical emergency, if you experience it, you should go to a hospital immediately.
  5. Allergic reactions such as rash, itching, difficulty breathing and swelling of tongue and throat may also occur.
  6. In rare cases, serious skin reactions like Stevens-Johnson syndrome can occur. Stevens-Johnson syndrome is a serious and life-threatening skin reaction characterized by loss of skin layers, facial swelling, fever, difficulty in breathing and raised welts.
  7. Intraoperative Floppy Iris Syndrome – This syndrome is a complication that occurs during Cataract surgery. It is also not a common side effect but has been reported to occur in some people who used Flomax.

These side effects may persist during the course of therapy, or if your dosage is changed abruptly. To alleviate these side effects, it is advised that the dose of the medication be increased or decreased slowly under the supervision of your doctor.

Unless your doctor says otherwise, you should not take Flomax if you have a very serious kidney problem, have liver disease or coronary artery disease, if you usually feel lightheaded when you stand up, or if you are prone to priapism.


Flomax is a commonly used drug due to its effectiveness in relieving BPH symptoms. If during use, you need to discontinue the medication for any reason, ensure it is done under the supervision of your doctor so as to reduce your risk of developing the above side effects after stopping.

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Grace Adejuwon, B.Pharm

Grace Adejuwon joined 25 Doctors in 2019. She has a bachelor's degree in Pharmacy from the Obafemi Awolowo University with many years experience in pharmaceutical care, logistics and pharmacy business management. She is also the lead pharmacist at Synapse Services Ltd, a community pharmacy. An ardent lover of nature, she delights in spending time within the pages of books. She uses her love for welding words together to educate people, especially about drugs.
Grace Adejuwon, B.Pharm

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