Monolosin 0.4mg capsule contains the active substance Tamsulosin. It is an alpha-adrenergic antagonist used in men to treat benign prostatic hyperplasia (enlarged prostate), which includes difficulty in urinating, painful urination, and urinary frequency and urgency. It is also used to reduce the tension in the muscles of the prostate and urethra. It belongs to the class of medications called alpha-blockers. It works by relaxing the muscles in the prostate and bladder so that urine can flow easily. Do not take this medicine if you are allergic to tamsulosin or any of the other ingredients of this medicine, or if angioedema (swelling due to allergic reaction) occurs after using of some drugs. Inform your physician if you have a serious infection of the liver, or if you suffer from dizziness, or if you have already had malaise while you urinate or after urinating (micturition syncope). If you are planning to undergo cataract or glaucoma surgery, please inform your doctor that you are taking or have recently taken Monolosin 0.4mg capsules. Caution should be paid if you have severely impaired renal function, as there is insufficient data from clinical studies about patients with severe renal impairment. In case of dizziness, it is necessary to sit down or lay down until the disappearance of these signs. Report to your physician if there is a drop in blood pressure on long-term use.