Flomax (tamsulosin) belongs to in a class of medications called alpha blockers. It works by relaxing the muscles in the prostate and bladder so that urine can flow easily. Flomax capsules are used in men to treat the symptoms of an enlarged prostate (benign prostatic hyperplasia or BPH) which include difficulty urinating (hesitation, dribbling, weak stream, and incomplete bladder emptying), painful urination, and urinary frequency and urgency.

Dosage and direction
Take Flomax capsules exactly as prescribed by your doctor. Flomax capsules are usually taken once a day, within 30 minutes after the same meal each day. Swallow the capsule whole and do not crush, chew, break, or open it.

Precautions
To make sure this medicine is safe for you, tell your doctor if you have ever had: prostate cancer; low blood pressure; an allergy to sulfa drugs; or liver or kidney disease.
Tamsulosin can affect your pupils. If you have cataract surgery, tell the surgeon you use this medicine.
Ask your doctor about prostate cancer screening before and while taking this medicine.

Contraindications
Flomax capsules are not approved for use in women or children.
You should not use Flomax if you are allergic to tamsulosin.
Do not take tamsulosin with other similar medicines such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), silodosin (Rapaflo), or terazosin (Hytrin).
Flomax may cause dizziness or fainting, especially when you first start taking it or when you start taking it again. Be careful if you drive or do anything that requires you to be alert. Avoid standing for long periods of time or becoming overheated during exercise and in hot weather. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Possible side effect
Get emergency medical help if you have signs of an allergic reaction to Flomax (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Tamsulosin may cause serious side effects. Stop using Flomax and call your doctor at once if you have: a light-headed feeling, like you might pass out; or a painful erection that lasts 4 hours or longer.
Common Flomax side effects may include: abnormal ejaculation, decreased amount of semen; dizziness, drowsiness, weakness; runny or stuffy nose, sore throat, cough; back pain, chest pain, headache; nausea, diarrhea; tooth problems; blurred vision; sleep problems (insomnia); or decreased interest in sex.

Drug interaction
Tell your doctor about all your current medicines. Many drugs can affect tamsulosin, especially: cimetidine; medicine to treat impotence or pulmonary arterial hypertension--avanafil (Stendra), sildenafil (Viagra, Revatio), tadalafil (Adcirca, Cialis), or vardenafil (Levitra, Staxyn); or drugs to treat high blood pressure or a prostate disorder--alfuzosin, doxazosin, prazosin, terazosin, silodosin.

Missed dose
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time. If you stop using this medicine for several days in a row, do not start it again without your doctor's advice.

Overdose
Seek emergency medical attention.

Storage
Store tightly closed at room temperature, away from moisture and heat.