Dutasteride - tamsulosin is a combination medication that is used to treat moderate-to-severe symptoms of benign prostatic hyperplasia (BPH). BPH is a noncancerous enlargement of the prostate gland that usually occurs in men after the age of 50.

Dutasteride belongs to a class of medications known as 5-alpha-reductase inhibitors. It works to reduce the production of dihydrotestosterone (DHT), a hormone that causes enlargement of the prostate gland. Dutasteride relieves symptoms of BPH by reducing the size of the prostate and improving the flow of urine.

Tamsulosin belongs to a group of medications known as alpha 1A receptor antagonists. 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.

Relief of symptoms such as decreased urine flow, difficulty urinating, needing to get up during the night to urinate or hesitation at the start of urination may be seen after 3 months of taking dutasteride - tamsulosin, however it may take 6 months or more to see the full effects of this medication.

Your doctor may have suggested this medication 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 this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

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

The recommended dose of dutasteride - tamsulosin is one capsule taken at the same time each day.

Many things can affect the dose of 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.

Dutasteride - tamsulosin should be taken approximately 30 minutes after the same meal each day. Swallow the capsule whole. Do not chew or open the capsule.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue 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 this medication at room temperature and keep it out of the reach of children.

Each oblong, hard-shell capsule, with a brown body and an orange cap imprinted with "GS 7CZ" in edible black ink, contains one oblong, opaque, dull-yellow dutasteride soft gelatin capsule containing dutasteride 0.5 mg and white-to-off-white tamsulosin hydrochloride sustained release pellets containing tamsulosin hydrochloride 0.4 mg.

Nonmedicinal ingredients: dutasteride soft gelatin capsule: mono-di-glycerides of caprylic/capric acid, butylhydroxytoluene, glycerol, gelatin, titanium dioxide, medium chain triglycerides, lecithin, and iron oxide yellow; tamsulosin hydrochloride sustained release pellets: microcrystalline cellulose, methacrylic acid - ethyl acrylate copolymer dispersion, talc, and triethyl citrate; hard-shell capsule: hypromellose, carrageenan, titanium dioxide, iron oxide red, FD&C Yellow No. 6, and potassium chloride imprinted in edible black ink.

Do not take this medication if you:

• are allergic to dutasteride, tamsulosin, or any ingredients of the medication
• have had an allergic reaction to finasteride

This medication should not be taken by or given to children or women.

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 this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. 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.

• constipation
• diarrhea
• dry mouth
• hair loss
• headache
• itchy, congested, or runny nose
• reduced interest in sex
• vomiting
• weakness or loss of strength

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

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

• breast enlargement
• breast tenderness
• dizziness or lightheadedness when rising from a lying or sitting position
• itchiness
• nose bleeds
• pain and swelling in the testicles
• performance problems during sex
• rapid, pounding, or irregular heartbeat
• rash
• shortness of breath
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• vision changes

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

• fainting
• painful, prolonged erection
• 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 (e.g., 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 this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Abnormal heart rhythms: Other medications similar to tamsulosin can cause abnormal heart rhythms. If you have heart disease and abnormal heart rhythms, or are taking medications that can increase the risk of a type of abnormal heart rhythm called QT prolongation, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Medications that can cause this abnormal heart rhythm include sotalol, quinidine, thioridazine, chlorpromazine, pimozide, moxifloxacin, mefloquine, pentamidine, arsenic trioxide, and tacrolimus.

Allergy: Some people who are allergic to sulfa medications also experience allergic reactions to tamsulosin. Before you take dutasteride - tamsulosin, tell your doctor about any previous adverse reactions you have had to medications, especially sulfonamides.

Contact your doctor at once if you experience signs of an allergic reaction, such as skin rash, itching, difficulty breathing or swelling of the face and throat.

Blood donation: Men taking this medication should not donate blood until at least 6 months have passed following their last dose. This is to prevent pregnant women from being exposed to dutasteride during a blood transfusion.

Cataracts: If you will be undergoing cataract surgery, tell your doctor that you are taking a medication that contains tamsulosin. Your surgeon may advise you to temporarily stop taking the medication before the surgery.

Grapefruit and grapefruit juice: Regularly eating grapefruit or drinking grapefruit juice while taking dutasteride - tamsulosin may cause an increase in the amount of medication in the body, thereby causing an increase in side effects. You should avoid regularly eating or drinking grapefruit products while taking this medication.

Kidney function: The effect of dutasteride - tamsulosin on people with kidney problems has not been studied. If you have kidney disease or reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: The effect of this medication on people with liver disease has not been studied. If you have liver disease or reduced liver function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Orthostatic hypotension: People taking tamsulosin may experience orthostatic hypotension, which is low blood pressure when getting up. If you experience dizziness or weakness, sit or lie down until the symptoms have disappeared. Fainting is the most severe symptom of orthostatic hypotension. To reduce the risk of this dizziness, rise slowly from a lying or sitting position.

If you experience fainting, contact your doctor as soon as possible. Do not drive a car or perform hazardous tasks until you are certain that this medication does not impair your ability to perform these tasks safely.

Priapism: Tamsulosin, one of the ingredients in this medication, may cause priapism, which is a painful and persistent erection of the penis that is unrelieved by sexual activity. This condition can lead to damage to the penis or impotence if it is not treated quickly. If you suspect that you have these symptoms, call your doctor or go to the emergency room as soon as possible.

Prostate cancer: Prostate cancer and BPH cause many of the same symptoms. These two diseases frequently coexist. An evaluation should be done to rule out prostate cancer before dutasteride - tamsulosin therapy is started. Neither dutasteride nor tamsulosin is intended to treat symptoms of prostate cancer.

There may be a link between dutasteride and a type of cancer called high-grade prostate cancer. The risk of this cancer while taking this medication is still considered very small. If you experience worsening symptoms or symptoms that do not improve within 6 months, discuss this with your doctor. 

PSA test: Dutasteride can decrease PSA (prostate specific antigen) levels by up to 50%. Doctors often measure PSA levels to test for prostate cancer. PSA levels can still be measured for this purpose, but your doctor will need to adjust the results in order for the test to be accurate. If you are having a PSA test, ensure your doctor knows that you are taking dutasteride.

Women and children: Dutasteride - tamsulosin is intended for use by men only. Women and children must avoid contact with dutasteride, as it is absorbed through the skin. If contact occurs, wash the exposed area immediately with soap and water.

Pregnancy: This medication is intended for use by men only. Women who may be pregnant must avoid touching any capsules containing dutasteride (even ones that are not leaking). Pregnant women or women who may be pregnant should not handle dutasteride because the medication can be absorbed through the skin and may cause abnormalities in the baby. If a pregnant woman accidentally comes in contact with the capsules, she should wash the contact area immediately with soap and water.

Breast-feeding: Dutasteride is not intended for use by women. It is not known if dutasteride passes into breast milk. Do not handle this medication if you are breast-feeding.

Children: This medication is not intended for use by children. The safety and effectiveness of dutasteride have not been established for use by children.

There may be an interaction between dutasteride - tamsulosin and any of the following:

• abiraterone acetate
• alpha/beta agonists (e.g., epinephrine, norepinephrine)
• alpha-1 blockers (e.g., alfuzosin, doxazosin,  prazosin, terazosin)
• alpha-agonists (e.g., clonidine, methyldopa)
• amiodarone
• angiotensin converting enzyme inhibitors (ACEIs; captopril, ramipril)
• angiotensin receptor blockers (ARBs; e.g., candesartan, irbesartan, losartan)
• anti-psychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• apomorphine
• aprepitant
• "azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
• beta-blockers (e.g., atenolol, carvedilol, metoprolol, propranolol, sotalol)
• brimonidine
• bromocriptine
• bupropion
• calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
• cinacalcet
• conivaptan
• darifenacin
• diuretics (water pills; e.g., furosemide, hydrochlorothiazide, triamterene)
• dronedarone
• duloxetine
• grapefruit or grapefruit juice
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• iron sucrose
• letermovir
• levodopa
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• mifepristone
• milk thistle (an herbal product)
• mirabegron
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• morphine
• nabilone
• nitrates (e.g., isosorbide dinitrate, isosorbide mononitrate, nitroglycerine)
• obinutuzumab
• paclitaxel
• pentoxifylline
• phenobarbital
• phosphodiesterase 5 inhibitors (e.g., sildenafil, tadalafil, vardenafil)
• pramipexole
• protein kinase inhibitors (e.g., ceritinib, crizotinib, dabrafenib, dasatinib, nilotinib)
• quinidine
• quinine
• riociguat
• rotigotine
• sacubitril
• selective serotonin reuptake inhibitors (SSRIs; e.g., paroxetine, fluoxetine, citalopram, sertraline)
• terbinafine
• warfarin

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 this medication. 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.