Flomax CR (Tamsulosin) belongs to a group of medications known as alpha 1A receptor antagonists. It is used to treat symptoms of enlarged prostate (Benign Prostatic Hyperplasia [BPH]).

As the prostate gland enlarges, it can put pressure on the urethra, the tube that carries urine away from the bladder to be expelled. This causes a weak urine stream or a feeling of not being able to empty the bladder completely. Flomax CR (Tamsulosin) helps to relax the muscles in the prostate and the opening of the bladder. This helps the stream of urine to flow more freely and the bladder to be emptied completely.

Flomax CR (Tamsulosin) does not shrink the prostate gland. Therefore, although symptoms are improved with treatment, prostate surgery may still be needed some time in the future if the prostate gland continues to enlarge.

Flomax CR (Tamsulosin) may be available under multiple brand names and/or in several different forms. Any specific brand name of Flomax CR (Tamsulosin) may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of Flomax CR (Tamsulosin) may not be used for all of the conditions discussed here.

Your doctor may have suggested Flomax CR (Tamsulosin) for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking Flomax CR (Tamsulosin), speak to your doctor. Do not stop taking Flomax CR (Tamsulosin) without consulting your doctor.

Do not give Flomax CR (Tamsulosin) to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take Flomax CR (Tamsulosin) if their doctor has not prescribed it.

The recommended dose for Flomax CR (Tamsulosin) controlled-release tablets is 0.4 mg once daily, taken with or without food taken at the same time each day.

The tablets must be swallowed whole. Do not crush or chew the tablets.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important that Flomax CR (Tamsulosin) be taken exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If you remember the day after your scheduled dose, skip the missed dose and continue on with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store Flomax CR (Tamsulosin) at room temperature and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Flomax CR (Tamsulosin). If you are concerned about side effects, discuss the risks and benefits of Flomax CR (Tamsulosin) with your doctor.

The following side effects have been reported by at least 1% of people taking Flomax CR (Tamsulosin). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abnormal ejaculation
• Constipation
• decreased sexual drive or performance
• Diarrhea
• dizziness or lightheadedness
• headache
• itching and Hives
• nausea
• skin rash
• stuffy or runny nose
• unusual weakness
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• dizziness when rising from a lying or sitting position
• fast, pounding heart beat
• fainting
• vision changes

Stop taking the medication and seek immediate medical attention if any of the following occur:

• priapism (painful, persistent erection of the penis that is not relieved by sexual activity)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with Fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Flomax CR (Tamsulosin).

Each controlled-release tablet for oral administration contains Flomax CR (Tamsulosin) HCl 0.4 mg. Nonmedicinal ingredients: hypromellose, iron oxide yellow E172, macrogol 7,000,000, macrogol 8,000, and magnesium stearate.

Do not take Flomax CR (Tamsulosin) if you:

• are allergic to Flomax CR (Tamsulosin) or any ingredients of the medication
• are taking certain medications that are removed from the body by the liver such as:
• clarithromycin
• ketoconazole
• nefazodone
• protease inhibitors (e.g., lopinavir, ritonavir)

Flomax CR (Tamsulosin) is not intended for use by women or children.

There may be an interaction between Flomax CR (Tamsulosin) and any of the following:

• Abiraterone
• Aldesleukin
• Aliskiren
• alpha/beta-agonists (e.g., Epinephrine, norepinephrine)
• alpha-agonists (e.g., Clonidine, methyldopa)
• other alpha-blockers (e.g., Alfuzosin, Doxazosin, Prazosin, Silodosin)
• Amiodarone
• angiotensin converting enzyme inhibitors (ACEIs; Captopril, Ramipril)
• angiotensin receptor blockers (ARBs; e.g., Candesartan, Irbesartan, Losartan)
• antipsychotics (e.g., Chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• Apalutamide
• Aprepitant
• "azole" antifungals (e.g., fluconazole, itraconazole, ketoconazole)
• barbiturates (e.g., Phenobarbital,)
• beta-adrenergic blockers (e.g., Atenolol, Propranolol, Sotalol)
• Bicalutamide
• Bosentan
• brimonidine
• Bupropion
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• Carbamazepine
• Celecoxib
• chloroquine
• Cimetidine
• Clobazam
• Cobicistat
• conivaptan
• Crizotinib
• Cyclosporine
• Dabrafenib
• Darifenacin
• Deferasirox
• diuretics (water pills; e.g., Furosemide, Hydrochlorothiazide, triamterene)
• Dronedarone
• Duloxetine
• Enzalutamide
• grapefruit juice
• Guanfacine
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delavirdine, efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., indinavir, lopinavir, nelfinavir, ritonavir)
• Hydralazine
• Idelalisib
• imatinib
• Imipramine
• isoniazid
• levodopa
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• Methadone
• mifepristone
• Mirabegron
• Mitotane
• Modafinil
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, Phenelzine, Rasagiline, Selegiline, Tranylcypromine)
• Nilotinib
• nitrates (e.g., Nitroglycerin, isosorbide dinitrate, isosorbide mononitrate)
• Obinutuzumab
• Oxcarbazepine
• Palbociclib
• Pentoxifylline
• Phenytoin
• phosphodiesterase 5 inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil)
• primidone
• rifabutin
• rifampin
• Ropinirole
• quinidine
• St. John's wort
• Sarilumab
• Sertraline
• siltuximab
• Stiripentol
• Ticlopidine
• Tocilizumab
• tolcapone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Flomax CR (Tamsulosin). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.